Manual Table of Contents - Osna-net

Transcription

original contents found at http://www.hillmanimages.com/912/ PDF created by Torbeyns Gilles
Manual Table of Contents
The Factory 912 Manual.
1. Engine
2.Fuel System
3.Electrical System
4.Rear Axle and Transmission
1. Engine
•
•
•
1.1 ENGINE DESCRIPTION
1.1.1 Numerical Designation Of Cylinders And Main Bearings ....................................11
1.1.2 Cross-Sectional View of Engine ........................................................................... 12
1.1.3 Bottom View ......................................................................................................... 14
1.1.4 Crankcase .............................................................................................................. 15
1.1.5 Crankshaft and Connecting Rods.......................................................................... 16
1.1.6 Pistons ................................................................................................................... 17
1.1.7 Cylinders ............................................................................................................... 18
1.1.8 Cylinder Heads...................................................................................................... 19
1.1.9 Cam Shaft...............................................................................................................20
1.1.10 Cooling System ................................................................................................... 21
1.1.11 Engine Lubrication System................................................................................. 22
1.1.12 Oil Cooling.......................................................................................................... 23
1.1.13 Oil Pressure Indicator ......................................................................................... 24
1.2 ENGINE DISASSEMBLY
1.2.1Disassembling Engine............................................................................................ 25
1.2.2 Remove the Exhaust System................................................................................. 26
1.2.3 Disconnect the Distributor .................................................................................... 27
1.2.4 Remove the Carburetors........................................................................................ 28
1.2.5 Remove the Oil Lines ........................................................................................... 29
1.2.6 Remove Oil Filler ..................................................................................................30
1.2.7 Remove Fan Shroud.............................................................................................. 31
1.2.8 Remove Fuel Pump and Distributor...................................................................... 32
1.2.9 Remove the Rockers ............................................................................................. 33
1.2.10 Remove Intake Manifolds................................................................................... 34
1.2.11 Remove Heads Cylinders and Pistons ................................................................ 35
1.2.12 Remove Crankshaft Pulley.................................................................................. 36
1.2.13 Remove Oil Pump Gears..................................................................................... 37
1.2.14 Remove Third Piece............................................................................................ 38
1.2.15 Remove Clutch.................................................................................................... 39
1.2.16 Remove the Crankshaft........................................................................................40
1.2.17 Remove Bearings and Lifters.............................................................................. 41
1.3 ENGINE ASSEMBLY
1.3.1 Engine Assembly Start.......................................................................................... 42
1.3.2 Assemble Crank and Cam Shaft in the Case......................................................... 43
1.3.3 Join the Case ......................................................................................................... 44
1.3.4 Assemble Fly Wheel, Clutch and Third Piece ...................................................... 45
1.3.5 Install Third Piece and Crankshaft Pulley............................................................. 46
1.3.6 Install Distributor and Oil Cooller ........................................................................ 47
2
•
•
•
•
•
1.3.7 Install Pistons and Cylinders................................................................................. 48
1.3.8 Install Heads.......................................................................................................... 49
1.3.9 Install Rocker Arms ...............................................................................................50
1.3.10 Finish Assembly.................................................................................................. 51
1.4 MANUAL COOLING SYSTEM REMOVAL1.4.1 R/R AIR BLOWER HOUSING
1.4.1 Engine Cooling System......................................................................................... 52
1.4.2 Remove the Air Cleaners and Heating Hoses....................................................... 53
1.4.3 Cooling System - Remove the Breather Hose ...................................................... 54
1.4.4 Cooling System – Removal................................................................................... 55
1.4.5 Cooling System Replace ....................................................................................... 61
1.4.6 Manual Cooling System Replace.......................................................................... 62
1.4.7 Remove Air Blower Housing................................................................................ 62
1.4.8 Install Air Blower.................................................................................................. 66
1.4.9 Manual Replace Cooling Blower.......................................................................... 67
1.4.10 Removing Cooling Blower ................................................................................. 67
1.4.11 Installation........................................................................................................... 68
1.4.12 Removal and Installation of the Cooling Blower Fan ........................................ 69
1.4.13 Fan part number ...................................................................................................70
1.4.14 Fan Mounting Detail ........................................................................................... 72
1.4.15 Removing Air Hoses........................................................................................... 73
1.4.16 Removing Euro Hose .......................................................................................... 74
1.4.17 Euro Hose Adjustment ........................................................................................ 75
1.4.18 Installing Lower Duct with Air Gates................................................................. 76
1.4.19 Installing Air Gate Assembly.............................................................................. 77
1.5 CHECKING AND ADJUSTING V-BELT TENSION
1.5.1 Checking V-Belt Tension...................................................................................... 78
1.5.2 Adjusting V-Belt Tension ......................................................................................80
1.6 DESCRIPTION OF THE 912 (356 B/T6) HEATING SYSTEM
1.6.1 Functional View of the Heating System (Germany and Sweden) ........................ 82
1.6.2 Functional Description.......................................................................................... 83
1.6.3 Operating description: Heater Control................................................................. 84
1.6.4 Bottom View of Vehicle ....................................................................................... 87
1.6.5 Description of the Export - Type Heating System................................................ 88
1.6.6 Functional View of the Heating System ............................................................... 88
1.6.7 Bottom View of Vehicle - Export Type Heater .................................................... 89
1.7 REMOVING AND INSTALLING EXHAUST MUFFLER
1.7.1 Remove Clamps from Heat Exchangers ................................................................90
1.7.2 Remove Muffler.................................................................................................... 91
1.7.3 Installation............................................................................................................. 91
1.8 ENGINE LUBRICATION SYSTEM
1.8.1 Oil Circuit in Cold Engine .................................................................................... 92
1.8.2 Oil Circuit at Operating Temperatures.................................................................. 93
1.8.3 Removing Oil Strainer .......................................................................................... 94
1.8.4 Magnetic Oil Filtering........................................................................................... 96
1.8.5 Pressure Relief Valve............................................................................................ 97
1.8.6 Bypass Valve......................................................................................................... 98
1.8.7 Bypass Valve at Start Up ...................................................................................... 99
1.8.8 Bypass Valve When Running ..............................................................................100
1.8.9 Removal Cap Screw............................................................................................ 101
1.8.10 Withdraw Spring and Plunger........................................................................... 102
1.8.11 Remove Oil Cooler ........................................................................................... 103
1.8.12 Remove Oil Pump............................................................................................. 105
1.8.13 Changing Bypass Oil Filter............................................................................... 107
3
•
•
•
•
1.9 HEADS
1.9.1 Removal Rocker Arm Carrier ............................................................................. 108
1.9.2 Remove rocker arm shafts................................................................................... 109
1.9.3 Rocker Arm Installation...................................................................................... 110
1.9.4 Tighten the Rocker Arm Shaft Nuts ................................................................... 111
1.9.5 Disassembling and Reassembling Rocker Arm Carrier...................................... 112
1.9.6 Remove Cylinder Head....................................................................................... 113
1.9.7 Position Cylinder Deflectors............................................................................... 115
1.9.8 Torque the Head Bolts ........................................................................................ 117
1.9.9 Install Pushrods ................................................................................................... 118
1.9.10 Install Rocker Arms .......................................................................................... 119
1.10 VALVES
1.10.1 Adjust Valves.................................................................................................... 120
1.10.2 Removing and Installing Valve Springs ........................................................... 121
1.10.3 Valve Spring ..................................................................................................... 122
1.10.3 Checking Valve Guides for Wear ..................................................................... 123
1.10.4 Checking and Reconditioning Valve Seats....................................................... 124
1.10.5 Seating, Inspecting and Testing Valves ............................................................ 128
1.10.6 Adjusting Valve Clearance ............................................................................... 129
1.10.7 Checking Valve Timing and Clearance ............................................................ 132
1.10.8 Removing and installing Valve Guides ............................................................ 133
1.10.9 Removing and installing Valve Seat Inserts ..................................................... 134
1.11 CYLINDERS AND PISTONS
1.11.1 Reconditioning and Exchange of Cylinder Heads ............................................ 135
1.11.2 Check Cylinder Head Displacement ................................................................. 135
1.11.3 Removing and Installing Cylinders................................................................... 136
1.11.4 Inspecting Cylinders ......................................................................................... 138
1.11.5 Cylinder Marking.............................................................................................. 139
1.11.6 Removing and Installing Pistons ...................................................................... 140
1.11.7 Remove and Mark Cylinders ............................................................................ 142
1.11.8 Heat Pistons ...................................................................................................... 143
1.11.9 Remove Pins and Rings .................................................................................... 144
1.11.10 Check Proper Size of Rings ............................................................................ 145
1.11.11 Check Ring Fit in Piston ................................................................................. 146
1.11.12 Install Piston Pins............................................................................................ 147
1.11.13 Inspecting Pistons ........................................................................................... 148
1.11.14 Piston Measuring Points.................................................................................. 149
1.11.15Piston Size Table.............................................................................................. 150
1.12 CRANKCASE
1.12.1 Crankcase Dissassembly ................................................................................... 151
1.12.2 Remove Oil Pump............................................................................................. 152
1.12.3 Remove Timing Gear Cover ............................................................................. 153
1.12.4 Separate the Case .............................................................................................. 154
1.12.5 Not Correct Position of Timing Gears .............................................................. 155
1.12.6 Install Timing Gear Cover ................................................................................ 156
1.12.7 Disconnect Distributor ...................................................................................... 157
1.12.8 Inspect and Install Pinion Shaft Washer ........................................................... 158
1.12.9 Install Pinion Shaft............................................................................................ 159
1.12.10 Insert Spring in Pinion Shaft........................................................................... 160
1.12.11 Install Bearing 4 Oil Seal ................................................................................ 161
1.12.12 Deform Oil Seal .............................................................................................. 162
1.12.13 Pry Oil Seal ..................................................................................................... 163
1.12.14 Heat and Remove Bearing 4 ........................................................................... 164
4
•
•
•
1.12.15 Install Oil Seal................................................................................................. 165
1.12.16 Timing Gear Cover R/R.................................................................................. 166
1.12.17 Timing Gear Cover O-Rings........................................................................... 167
1.12.18 Rubber Plugs on Timing Gear Cover.............................................................. 168
1.12.19 Flywheel R/R .................................................................................................. 169
1.12.20 Flywheel Installation....................................................................................... 171
1.12.21 Dowel Pin Position.......................................................................................... 172
1.12.22 Reconditioning Flywheel ................................................................................ 173
1.12.23 Crankshaft Pulley Diagram............................................................................. 174
1.12.24 Flywheel Oil Seal R/R .................................................................................... 175
1.12.25Camshaft Remove / Install............................................................................... 176
1.12.26 Timing Gear Position ...................................................................................... 177
1.12.27 Camshaft Gear Marking.................................................................................. 178
1.12.28 Install Crankshaft ............................................................................................ 179
1.12.29 Connecting Rods R/R...................................................................................... 180
1.12.30 Torque Connecting Rods ................................................................................ 181
1.12.31 Tap to Rods Relieve Stress ............................................................................. 182
1.12.32 Check Clearance ............................................................................................. 183
1.12.33 Installing Connecting Rod .............................................................................. 184
1.12.34 Measuring and Realigning Connecting Rods.................................................. 184
1.12.35 Checking for Twisted Connecting Rods ......................................................... 185
1.13 CRANKSHAFT
1.13.1 Crankshaft Disassembly.................................................................................... 187
1.13.2 Crankshaft Reassembly..................................................................................... 188
1.13.3 Crankshaft End Play.......................................................................................... 189
1.13.4 Measure End Play ............................................................................................. 190
1.13.5 Calculating End Play......................................................................................... 191
1.13.6 Reconditioning Crankshaft ............................................................................... 193
1.13.7 Measuring Bearing Inserts ................................................................................ 196
1.14 CLUTCH
1.14.1 Diagram of the Clutch....................................................................................... 197
1.14.2 Remove Clutch.................................................................................................. 198
1.14.3 Clutch Installation ............................................................................................. 199
1.14.4 Measure Clutch Thickness .................................................................................200
1.14.5 Check Clutch Disk for Runout.......................................................................... 201
1.14.6 Inspecting Clutch Assembly ............................................................................. 202
1.14.7 Check Pressure Plate......................................................................................... 202
1.14.8 Check Clutch Attachment Points ...................................................................... 203
1.14.9 Check Wear of Rivet Heads.............................................................................. 204
1.14.10 Adjusting Clutch ............................................................................................. 205
1.14.11 Adjust Clutch Free-Play at Control Lever ...................................................... 205
1.14.12 Adjust Free-Play at Clutch Pedal .................................................................... 206
1.14.13 Adjusting Clutch Travel.................................................................................. 207
1.14.14 Adjusting Clutch Pedal Travel........................................................................ 208
1.15 TOLERANCES AND WEAR LIMITS
1.15.1 Cylinder Seat Depth in Cylinder Head ............................................................. 209
1.15.2 Cylinder Bore Ovality....................................................................................... 210
1.15.3 Piston Ring Gap ................................................................................................ 210
1.15.4 Piston Pin to Connecting Rod Clearance .......................................................... 211
1.15.5 Crank Pin to Connecting Rod Clearance .......................................................... 211
1.15.6 Crankshaft to Main Bearing Clearance............................................................. 212
1.15.7 Crankshaft Runout ............................................................................................ 213
1.15.8 Crankshaft to Crankshaft Thrust Bearing ......................................................... 214
1.15.9 Diagram of the Clutch....................................................................................... 215
5

1.15.10 Crankshaft Pulley Runout ............................................................................... 216
1.15.11 Camshaft Bearing Clearance........................................................................... 217
1.15.12 Camshaft End Play at Thrust End ................................................................... 218
1.15.13 Camshaft Center Bearing Runout ................................................................... 219
1.15.14 Lateral Runout................................................................................................. 219
1.15.15 Vertical Runout ............................................................................................... 220
1.15.16 Flywheel Lateral Runout................................................................................. 220
1.15.17 Flywheel Vertical Runout ............................................................................... 221
1.15.18 Flywheel Diam of Oil Sealing Surface ........................................................... 222
1.15.19 Flywheel Depth of Recess to Web.................................................................. 223
1.15.20 Flywheel Web Thickness ................................................................................ 224
1.15.21 Flywheel Width of Oil Sealing Area............................................................... 224
1.15.22 Valve Guide Clearances.................................................................................. 225
1.15.23 Valve Seat ....................................................................................................... 226
1.15.24 Valve Springs.................................................................................................. 227
1.15.25 Valve Spring Lengths...................................................................................... 228
1.15.26 Valve Lifter Dimensions................................................................................. 229
1.15 27 Oil Pump ......................................................................................................... 230
1.15.28 Pressure Relief Spring..................................................................................... 231
1.15.29 Torque Values for Bolts and Nuts .................................................................. 232
6
2. Fuel System
The fuel system consists of the carburetors, fuel pump, fuel tank and fuel lines.
• 2.1 FUEL SYSTEM DESCRIPTION................................................................................ 233
• 2.2 DESCRIPTION OF THE SOLEX 40 P II - 4 CARBURETOR
2.2.1 Solex 40 P II-4 Solid Shaft Parts list................................................................... 234
2.2.2 Solex 40 PII-4 Split Shaft Parts List ................................................................... 238
2.2.3 Solex 40 P II-4 Diagram ..................................................................................... 243
2.2.4 Solex 40 P II-4 Cross Section ............................................................................. 244
2.2.5 Solex 40 P II-4 Lateral Cross Section ................................................................. 245
2.2.6 The Float Chamber.............................................................................................. 246
2.2.7 Idle Metering....................................................................................................... 247
2.2.8 Intermediate Metering ......................................................................................... 248
2.2.9 Partial Load ......................................................................................................... 249
2.2.10 Full Power with Enrichment ............................................................................. 250
2.2.11 Acceleration ...................................................................................................... 251
2.2.12 Check Valve ...................................................................................................... 252
2.2.13 Carburetor Specifications2.2 Solex Carburetors .............................................. 253
• 2.3 REPAIR PROCEDURES
2.3.1 Removing and Installing Fuel Line..................................................................... 254
2.3.2 Removing and Installing Carburetor................................................................... 255
2.3.3 Cleaning Carburetor ............................................................................................ 256
2.3.4 Disassembling and Reassembling Carburetor..................................................... 257
2.3.5 Inspection and Reassembly ................................................................................. 258
2.3.6 Adjusting Injection Quantity............................................................................... 259
2.3.7 Adjusting Idle Speed ........................................................................................... 261
2.3.8 Checking Carburetor Float Level........................................................................ 263
2.3.9 Removing and Installing Air Cleaners ................................................................ 265
2.3.10 Removing and Installing Intake Duct ............................................................... 266
2.3.11 Removing and Installing Throttle Linkage ....................................................... 266
2.3.12 Adjusting Throttle Linkage ............................................................................... 267
2.3.13 Carburetor Service Diagnosis ........................................................................... 267
•
2.4 FUEL PUMP
2.4.1 Fuel Pump Schematic.......................................................................................... 269
2.4.2 Schematic of Manual Fuel Pump Drive .............................................................. 271
2.4.3 Pump Side of Mechanical Fuel Pump ................................................................. 272
2.4.4 Actuating Side of Mechanical Fuel Pump .......................................................... 273
2.4.5 Testing Pump Pressure ........................................................................................ 274
2.4.6 Removing and Installing Fuel Pump................................................................... 275
2.4.7 Reconditioning Fuel Pump.................................................................................. 277
7
3. Electrical System

3.1 ELECTRICAL SYSTEM DESCRIPTION………………………………………..280
3.2 LAMPS AND FUSES……………………………………………………………..282
3.3 GENERATOR DESCRIPTION………………………………………………..….284
3.3.1 Changing Ignition Warning Light……………………………………….287
3.3.2 Checking the Generator………………………………………………….288
3.3.3 Removing and Refitting Regulator Switch………………………………290
3.3.4 Checking Carbon Brushes and commutator…...………………………....290
3.3.5 Removing and Refitting Generator……………......………………..........291
3.3.6 Dismantling and Reassembling Generator…………………………...…..291
3.3.7 Checking Armature…………………………………………………...….292
3.3.8 Generator Faults and their Elimination…………………………………..295
• 3.4 ENGINE STARTER DESCRIPTION……………………………………………..296
4. Rear Axle and Transmission
•
4.1 ADJUSTING GEARSHIFT LINKAGE
4.1.1 Remove Cover…………………………………………………………...299
4.1.2 Loosen Hex Bolt…………………………………………………………299
4.1.3 Set Selector………………………………………………………………300
8
1. ENGINE
1.1 912 ENGINE DESCRIPTION
The engine shown is for a 1965-1966 SWB car and has the German heating
system. There is no smog equipment on the car other than crank case
ventilation from the oil filler can to the right hand head.
In late 1966 the motor mount changed from the flat plate shown to a Ushaped channel with 4 rubber motor mounts.
The arrow points to the engine serial number.
As you already know, there is great similarity between the 912 and 1600 SC
engine. Thus you will find many familiar instructions in this Service Guide for
the 912 engine.
Chassis design of the 912 Porsche is basically the same as that of the Type911. Consequently, you may apply the workshop manual for the Type 911, in
combination with this Service Guide for the 912 engine, to the 912 Porsche as
well.
The choice of arranging your Porsche manuals is being left to your discretion.
You may remove from your 911'Workshop Manual the chapter dealing with the
9
911 engine and replace it with this Service Guide for the 912 engine, thus
having a complete 912 Workshop Manual; you may supplement your 911
Workshop Manual with this Service Guide for the 912 engine to have both
types in a single book; or you may retain your 911 Workshop Manual and this
Service Guide for 912 engines in separate books to have ample space in each
book for the inclusion of notes and supplements.
The procedures, tool application and identification have, of course, been
adopted from the 911 Workshop Manual.
10
1.1.1 Numerical Designation Of
Cylinders And Main Bearings
Here we see a diagram of the engine showing how the cylinders are numbered.
One additional piece of information is the cylinder firing order: 1-4-3-2
Cylinders
Viewed in direction of travel;
•
•
•
•
Cylinder
Cylinder
Cylinder
Cylinder
I: Front, right side
II; Rear, right side
III: Front, left side
IV: Rear, left side
MAIN BEARINGS
Bearing
1.
2.
3.
4.
Inside
Inside
Inside
Inside
diameter
diameter
diameter
diameter
50
55
55
40
mm,
mm,
mm,
mm,
sleeve insert (flywheel-end)
split insert
split insert
sleeve insert (at crankshaft pulley)
11
1.1.2 Cross-Sectional View of Engine
Fig. 3
The figure shows a cutaway view of the engine with major items identified.
Cross-Sectional View of the Engine
1. Clutch
2. Flywheel
3. Main bearing journal. Bearing 2
4. Cooling air inlet
5. Cooling blower impeller
6. A ir blower housing
7. Oil filler
8. Generator
9. Generator carrier
10.
V-belt
11.
Spacers, adjusting V-belt tension
12.
Bearing sleeve. Bearing 4
13.
Pulley retaining nut
14.
Flywheel gland nut
15.
Cylinders and pistons
16.
Camshaft
17.
Oil strainer
18.
Magnetic filtering el<
19.
Connecting rod bearii
12
20.
21.
22.
23.
24.
25.
Oil suction tube
Timing gear
Oil pump
Camshaft drive gear
Distributor drive gear
Crankshaft pulley
13
1.1.3 Bottom View
Fig. 5
The bottom view again shows the German edition of the 912 with different
heater components including modified heat exchangers and muffler. This
version was used for Sweden and Germany. The rest of the world recieved
'flapper boxes' patterned after the VW Beetle of the period. Notice also that the
mounting system for the exhaust system is different with what appears to be
connections to the third piece of the engine case.
Bottom View of Vehicle
1. Transmission filler plug
2. Transmission drain plug
3. Transmission
4. Clutch control lever
5. Engine drain plug
6. Oil strainer cover
7. Crankcase
8. Exhaust muffler
9. Forward power train carrier
10.
Suspension control arm
11.
Heating air control gates
12.
Axle shaft
13.
Shock absorber
14.
Heat exchanger
15.
Tail pipe
14
1.1.4 Crankcase
We often refer to the timing gear cover as the 'third piece'. The manual
description is interesting because there it includes assembly instructions which
seem out of place in this section of the manual.
The cast - light alloy crankcase consists of two crankcase sections and a timing
gear cover. It is possible to replace the timing gear cover alone, if the dowel
pin bores are bored to 8,1 mm diameter. before assembling. When assembling,
first tighten the screw lightly, then while turning the crankshaft tighten to the
correct torque.
15
1.1.5 Crankshaft and Connecting
Rods
Fig. 7
Here we see the crankshaft and connecting rods.
The four connecting rods ride on the plain-bearing crankshaft in lead-bronze
bearing inserts. All connecting rods have bronze piston pin bushings. All
crankshaft journals are soft nitrided. Bearings 2 and 3 (seen from the clutchend) are split-sleeve inserts. Bearing 4 may be replaced without disassembling
the crankcase by removing the timing gear cover.
Bearing 1 also takes up the crankshaft thrust. The flywheel, which also carries
the starter gear teeth, is attached to the crankshaft by means of a gland nut
and fixed in position by 8 aligning dowel pins. The camshaft gear and the
distributor drive gear are locked to the crankshaft through Woodruff keys. The
crankshaft pulley is attached to the crankshaft through a hex bolt and locked
with a Woodruff key. The crankshaft is sealed in the crankcase through oil
seals located at the flywheel and crankshaft pulley ends.
16
1.1.6 Pistons
Fig. 8
The light-alloy pistons in the Type 912 engine have 3 piston rings each, the
lowest ring being the oil scraper. The piston pins float in the connecting rod
bushings; they are contained within the pistons through the use of circlips.
17
1.1.7 Cylinders
A big bore kit has larger diameter pistons, from 83.5mm to 86mm. The
cylinder description is, of course, for the stock cylinder which are not suitable
to be bored out to accept the larger diameter pistons. Cast iron cylinders used
for the 356C engines are often used for this purpose.
The cylinders are made of carbon steel encased with light-alloy cooling fins.
18
1.1.8 Cylinder Heads
The clylinder heads are symetrical left and right. The combustion chamber
needs to be modified for the narrower sealing surface of big bore cylinders.
Each bank of two cylinders has a common, heavily finned, cast light alloy
cylinder head with shrunk-in valve seats and valve guides. Helicoil inserts are
used as spark plug seats. The cylinder head accommodates the valves in a "V"
arrangement. No gasket is used between the cylinder head and the cylinders.
19
1.1.9 Cam Shaft
The 3-journal camshaft rides on the base metal of the crankcase. Camshaft
drive is through helical gears; the timing gear is of light alloy. Valve timing is
effected through cams, valve lifters, push rods, and rocker arms. Each cam
alternately actuates one valve of two opposing cylinders. The exhaust valves
are cased with high-grade chrome-nickel steel.
20
1.1.10 Cooling System
Fig. 12
The engine is cooled by an air blower. The blower impeller is situated on the
extended generator shaft which is driven by the crankshaft over a V-belt. The
blower draws cooling air through an intake in the blower housing and forces it
over the heavily finned cylinders and cylinders heads. The cooling air is guided
by deflector baffles.
21
1.1.11 Engine Lubrication System
Fig. 13
The engine oil supply is in the bottom of the case, normal with wet sump
lubrication systems and unlike the 911.
Engine lubrication is effected through a forced feed system and includes an oil
cooling provision.
The oil pump is situated in the timing gear cover and is driven by the
camshaft. The oil is picked up from the lowest point in the crankcase and
forced into the oil cooler and the oil galleries. Part of the oil is forced through
the main bearings into the drilled oil galleries in the crankshaft and lubricates
the connecting rod bearings. A second part of the oil lubricates the camshaft
bearings, and still another part passes through the hollow pushrods to the
rocker arm bearings, also lubricating the valve shafts. Cylinder walls, pistons,
and piston pins are lubricated through oil splash. Oil draining from the points
of lubrication collects in the bottom of the crankcase where it passes through
an oil strainer and a magnetic filtering element, both entrapping foreign matter
that may be suspended in the oil. A bypass oil filter additionally cleans the
circulating oil.
22
1.1.12 Oil Cooling
The stock oil cooler is made of steel and is associated with cracks in the case.
An aluminum replacement is available which has better head transfer
characteristicsand is lighter weight, putting less stress on the case.
The oil cooler is mounted on the crankcase in the stream of cooling air forced
through by the cooling blower. The oil cooler is so inserted into the oil circuit
that the oil pumped by the oil pump must pass through the oil cooler before it
reaches the points of lubrication. Cooling of the oil ensures that it retains its
full lubricating qualities even in very warm weather and under constant
operating loads. When the oil is cold and thick flowing, a pressure relief valve
permits the oil to bypass the oil cooler and flow directly into the oil galleries.
23
1.1.13 Oil Pressure Indicator
Fig. 15
There are two electrical sending units shown in the diagram. The vertical one is
the pressure sender and the horizontal one behind it is the temperature
sender. It is not uncommon for these to fail and to leak oil.
A pressure-actuated switch is connected to the pressure gallery between the
pump and oil cooler. The switch opens the electric circuit of the oil pressure
indicator lamp at a pressure between 0.3 and 0. 6 aim (4. 5 - 8. 8 psi),
causing the lamp to go out. The lamp glows when the ignition is turned on and
the oil pressure is low.
24
1.2 MANUAL ENGINE DISASSEMBLY
1.2.1 Disassembling Engine
Fig. 17
The maunal calls out some special tools that are used for Dissembling and
Assembling the engine. It is assumed in this series that the engine has been
removed from the car.
Special Tools:
•
•
•
•
•
•
P la - Electric piston heater
P 2 - Piston pin mandrel
P 8a - Piston ring compressor
P 42 - Torque wrench, 50 mkg (362 lbs/ft), flywheel tightening and
loosening
P 44 - Hex socket, 36 mm, flywheel tightening and loosening
VW 307 - Engine and transmission bench mount
Disassembly
Disassemble the engine in the following order:
•
1. Drain engine oil.
25
1.2.2 Remove the Exhaust System
Fig. 18
The shields are the horizontal sheet metal. Removing the exhaust system is
often difficult after years of use but replacement parts are still being made, so
a cut-off saw may be considered.
•
•
2. Remove engine front, rear and side Shields.
3. Remove exhaust muffler and exhaust pipes with heat exchangers.
26
1.2.3 Disconnect the Distributor
Fig. 17
•
4. Detach cable connecting coil and distributor, remove distributor cover.
27
1.2.4 Remove the Carburetors
Fig. 19
•
•
•
•
5.
6.
7.
8.
Remove
Remove
Remove
Remove
air cleaners.
fuel lines and throttle linkage.
carburetors (2 Fu).
V-belt.
28
1.2.5 Remove the Oil Lines
Fig. 20
•
9. Detach oil lines from bypass oil filter.
29
1.2.6 Remove Oil Filler
Fig. 21
The picture shows the Euro fan shroud and a braket used to hold the air hose.
This is not included on the U.S. model.
•
10. Remove oil filler.
30
1.2.7 Remove Fan Shroud
Fig. 22
Not mentioned are many details including the generator strap and that the
generator can remain attached to the fan shroud for this operation.
•
•
•
•
11. Remove shroud retaining bolts.
12. Unfasten generator,
13. Withdraw blower housing. (See cooling)
14. Remove cylinder shrouds and, in cases involving the Export heater,
lower air ducts. (See cooling)
31
1.2.8 Remove Fuel Pump and
Distributor
Fig. 23
The picture shows only the generator carrier.
•
•
•
15. Remove fuel pump (13 Fu).
16. Remove distributor and distributor pinion shaft.
17. Remove generator carrier.
32
1.2.9 Remove the Rockers
Fig. 24
The rockers cover some of the access to the head studs, so must be removed
first.
•
•
•
18. Remove rocker box Covers.
19. Remove rocker arms.
20. Remove rocker arm carriers.
33
1.2.10 Remove Intake Manifolds
Fig. 25
•
•
21. Pull out pushrods.
22. Remove intake ducts.
34
1.2.11 Remove Heads Cylinders and
Pistons
It would be good to take pictures of each stage of dissassembly to guide in
reassembly.
•
•
•
23. Remove cylinder heads
24. Remove pushrod tubes and air deflector baffles.
25. Remove cylinders and pistons, marking each for reassembly.
35
1.2.12 Remove Crankshaft Pulley
912_fig_27
Notice that the U.S. models did not include the exhaust muffler brackets that
are seen in this picture.
•
•
26. Remove crankshaft pulley, withdraw Woodruff key.
27. Remove exhaust muffler brackets.
36
1.2.13 Remove Oil Pump Gears
Fig. 28
•
•
28. Remove oil pump cover.
29. Withdraw oil pump gears.
37
1.2.14 Remove Third Piece
Fig. 29
•
30. Remove timing gear cover.
38
1.2.15 Remove Clutch
Fig. 30
•
31. Remove clutch.
39
1.2.16 Remove the Crankshaft
•
•
•
•
32.
33.
34.
35.
Remove flywheel.
Remove oil strainer cover and oil strainer.
Disassemble crankcase.
Withdraw crankshaft and camshaft.
40
1.2.17 Remove Bearings and Lifters
Fig. 32
•
•
•
36. Withdraw valve lifters.
37. Withdraw bearing 2 and 3 inserts.
38. Remove oil seal, deflector, bearing 4 and bypass valve from the
timing gear cover.
41
1.3 MANUAL - ENGINE ASSEMBLY
1.3.1 Engine Assembly Start
Fig. 33
Now we can start putting the engine back together.
Reassemble engine in reversed order of the above, noting the following points:
•
•
•
1. Thoroughly clean crankcase parts, flush oil passages with clean
gasoline, install oil drain plug.
2. Install bearing inserts for Bearing 2 and 3 into the right and left
crankcase halves.
3. Lubricate valve lifters with graphite oil and install.
42
1.3.2 Assemble Crank and Cam Shaft
in the Case
•
•
•
4. Check dowel pin in Bearing 1 for firm seating.
5. Place assembled crankshaft into crankcase half.
6. Place cam shaft into crankcase half.
43
1.3.3 Join the Case
Fig. 35
•
•
•
7. Insert thrust washer and oil seal.
8. Install camshaft end plus,.
9. Join both crankcase halves.
44
1.3.4 Assemble Fly Wheel, Clutch
and Third Piece
Fig. 36
•
•
•
•
10. Install flywheel.
11. Install clutch.
12. Install oil strainer and oil strainer cover.
13. Install Bearing 4, deflector, oil seal, bypass valve, counter-pressure
oil line, and oil pump, into the timing gear cover. Install timing gear
cover, check Bearing 4 set screw for firm seating.
45
1.3.5 Install Third Piece and
Crankshaft Pulley
Fig. 37
•
•
•
14. Install crankshaft pulley shield.
15. Install crankshaft pulley.
16. Insert distributor pinion shaft with thrust washer and spring.
46
1.3.6 Install Distributor and Oil
Cooller
Fig. 38
•
•
•
17. Install distributor.
18. Install fuel pump.
19. Install oil cooler.
47
1.3.7 Install Pistons and Cylinders
Fig 39
•
20. Install pistons and cylinders. Do not fail to install cylinder base
gaskets.
48
1.3.8 Install Heads
Fig. 40
•
•
•
•
21. Install deflector baffles with supporting springs.
22. Install pushrod covers with gaskets.
23. Insert cylinder head and tighten. Note proper location of cylinder
shrouds.
24. Squirt oil into pushrods and insert in place.
49
1.3.9 Install Rocker Arms
•
•
25. install rocker arm carriers.
26. Adjust valve clearance, install rocker box covers.
50
1.3.10 Finish Assembly
Fig. 42
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
27. Install spark plugs.
28. Install intake manifolds using new gaskets (clean the gasket
surface).
29. Insert blower housing with generator.
30. Install cylinder shrouds.
31. Install fuel pump shield.
32. Fasten lower air ducts (Export heater).
33. Install cylinder end shrouds.
34. Attach oil lines to bypass oil filter and oil- pressure switch, check for
leakage.
35. Fasten generator strap, spin generator shaft to ensure that blower
impeller is not binding.
36. Install V-belt.
37. Connect cable to Terminal I connecting coil and distributor.
38. Install carburetors, throttle linkage, and fuel line.
39. Install oil filler.
40. Install air cleaners.
41. Connect ignition leads.
42. Install exhaust muffler, connecting with heat exchangers.
43. Fill engine oil, run engine briefly and recheck oil level, replenish if
necessary.
51
1.4 MANUAL COOLING SYSTEM
REMOVAL
1.4.1 Engine Cooling System
Fig. 43
1.
2.
3.
4.
5.
6.
Engine front shield
Engine side shield
Cylinder shroud
Blower housing
Engine side shield
Engine rear shield
52
1.4.2 Remove the Air Cleaners and
Heating Hoses
Fig. 44
•
•
•
1. Remove air cleaners from both carburetors.
2. Loosen the right and left heating hose attaching clamps.
3. Loosen the center hose clamp and, pushing it to the right, remove
from the attaching tab.
53
1.4.3 Cooling System - Remove the
Breather Hose
•
•
4. Remove transverse engine carrier (4 bolts); in cars equipped with the
newer version of the carrier also remove the carrier plate.
5. Remove crankcase breather hi from breather.
54
1.4.4 Cooling System - Removal
These instructions apply to the Euro heating system.
•
•
6. Remove heating hose connecting flange from the air blower housing.
7. Remove short connecting hose from rear engine cover panel.
•
8. Remove retaining screws from the engine rear shield and withdraw
shield by pulling rear ward.
9. Remove side shield on right and left sides, withdraw together with
breather.
•
55
•
•
•
10. Remove engine front shield.
11. Remove exhaust muffler.
12. Remove heat exchanger
•
13. Detach cables connecting the distributor and coil, and remove
distributor cover.
56
•
•
•
14. Remove caruretors (2 Fu).
15. Remove V-belt.
16. Remove oil breather.
57
•
•
•
18. Remove Distributor.
19. Remove Fuel Pump.
58
•
20. Remove both transverse carrier supposts
•
•
•
21. Remove cover shrouds.
22. Unfasten generator retaing strap.
23. Withdraw blower housing.
59
•
•
•
24. Remove cylinder shrouds and lower air duct.
25. After removing the cylinder heads, withdraw deflector baffles and
supporting springs.
26. Using a puller, withdraw crankshaft pulley and remove pulley shield.
60
1.4.5 Cooling System Replace
The cooling air shroud should be reinstalled in reversed order of the above,
making certain that the shrouds are well fitted and the spark plug rubber
covers properly seated. Torn, porous, or otherwise defective rubber gaskets
must be replaced, A 11 rubber parts should be kept free of grease and oil.
Particular attention must be given to proper placement of the deflector baffles.
To the left is Deflector baffle for Cyl 3 and 4
To the right is Deflector baffle for Cyl 1 and 2
61
1.4.6 Manual Cooling System Replace
1.4.7 Remove Air Blower Housing
•
1. Detach throttle linkage from both throttle control levers,
62
•
•
•
2. Remove carburetors and fuel supply line.
3. Detach throttle control linkage.
4. Remove generator retaining strap.
63
•
64
•
•
•
6. Detach ignition leads from spark plugs, and cable connecting
distributor with coil, remove distributor cover.
7. Remove retaining screws from cylinder end and side shrouds.
8. Detach heating air connecting flange from air blower housing.
65
9. Remove air blower housing by pulling it up.
1.4.8 Install Air Blower
Install the air blower housing in reversed order of the above by noting the
following points:
1. The cover shrouds must join their counterparts with good fit to preclude loss
of cooling air.
2. With engine installed, properly connect the generator cables.
3. Adjust carburetor linkage.
4. Check gasket at the oil filler stack, replace if necessary.
66
1.4.9 Manual Replace Cooling
Blower
The detachable generator carrier permits withdrawal of the generator and
blower impeller assembly without removal of the entire air blower housing. The
work procedure is as follows:
1.4.10 Removing Cooling Blower
•
•
•
•
•
1.
2.
3.
4.
5.
Remove V-belt and detach generator cables.
Loosen generator retaining strap.
Remove oil filler stack.
Remove bypass oil filter assembly.
Remove retaining bolts from the blower housing cover.
67
•
•
6. Remove generator carrier, cover the crankcase opening to prevent
entry of foreign matter.
7. Withdraw the generator and blower impeller assembly.
1.4.11 Installation
The installation is accomplished in reversed order of the above by noting the
following points:
1. Properly connect generator cables (brown cable to Terminal D-, black
cable to Terminal DF, red cable to Terminal D+).
2. Insert new gasket between the generator carrier and timing gear cover.
3. Check for proper V-belt alignment between the generator and crankshaft
pulleys and correct be repositioning the generator in its cradle; however,
make certain that no tension is created between the blower housing
cover and the blower housing when the retaining screws are tightened.
68
1.4.12 Removal and Installation of
the Cooling Blower Fan
Special Tools
P 42 Torque wrench, or
VW 118 Torque wrench
P 44 Hex socket. 36 mm, for P 42,
Removal
Diagram of the fan installation to the generator shaft.
1. Remove air blower.
2. Mount generator in a vice by fastening it by the pulley
spindle through plastic or aluminum grip protectors.
3. Unscrew the special impeller nut and withdraw impeller
together with its back shield.
Installation
1.
2.
3.
4.
Note the proper arrangement of spacers.
Position impeller shield.
Tighten the special impeller nut to 10 mkp (72. 3 lbs/ft).
The clearance between the blower housing cover and impeller should be
approximately 3 mm (1/8 in.).
5. When turning, the impeller should not strike the housing cover.
69
1.4.13 Fan part number
Parts Manual
There is a difference between the parts for the small and larger generator.
49
900.028.008.01
Spring Washer. B 6 DIN 137 bost.
5
50
900.075.010.02
Hexagon Srew M 6x12 DIN 933-8G
5
52
616.106.181.00
Nut for fan for generator 350 W
1
(52)
547.09.303
Nut for fan for generator 420 W
2
53
616.106.011.00
Fan for generator 350 W
1
(53)
616.106.023.00
Fan for generator 420 W
1
54
546.06.204
Cover plate for generator 350 W
1
(54)
616.106.337.00
1
55
546.06.202
Washer
1
56
546.06.203
Carrier plate for generator 350 W
1
57
539.09.314
Washer
19
70
58
539.06.201
Hub for fan for generator 350 W
1
(58)
616.106.201.00
Hub for fan for generator 420 W
1
59
539.06.102
Reinforcement flange for generator 350 W
1
(59)
616.106.339.00
-
616.106.115.00
1
60
616.106.125.00
Distance ring
1
61
616.106.105.01
Cover for fan housing, generator 350 W
1
(61)
616.106.024.00
Cover for fan housing, generator 420 W
1
Reinforcement flange for fan cover for generator
350 W
71
1
1.4.14 Fan Mounting Detail
Diagram of the fan installation to the generator shaft.
1. Thick washer
2. Impeller back shield
3. Thick washer
4. Generator shaft
5. Blower housing cover
6. Special impeller nut
7. Impeller
8. Spacers (as needed, 2-5 each)
9. Impeller hub
10.
Generator
72
Manual Replace Hoses, Ducts and
Gates
Air Hose Connecting Duct
Removal
1.4.15 Removing Air Hoses
•
•
1. Detach heating hose from connecting duct.
2. Detach breather hose from breather.
73
1.4.16 Removing Euro Hose
•
3. Remove retaining nut and bolt from the connecting duct. Push rubber
hose section down and off the duct, pull duct diagonally upward.
74
1.4.17 Euro Hose Adjustment
•
•
1. Check adjustment of the counter-nut used for fastening the
connecting duet. The nut must be screwed in deep enough to permit
flush alignment of the connecting duct with the blower housing without
deformation of the duct when tightened at the attaching points.
2. Inspect heating hose and breather hose for airtightness and possible
damage.
75
1.4.18 Installing Lower Duct with
Air Gates
Export Heater
The air gates, located in the lower air duct must be so adjusted that they
perform the opening and closing functions in unison. Ensure that the large air
gate flaps are positioned approx 10 mm (2/5in.) from the bottom of the ducts
when the small air gate flap is fully closed. Upon mounting the lower ducts at
the engine, check for proper functioning of the air gates and readjust if
necessary.
76
1.4.19 Installing Air Gate Assembly
The following points should be observed when installing the air gate assembly:
Heating Hose attachment
Check for proper seating of the 2,5 mm-thick cork gasket.
Check heating hose attachment for air-tightness and firm seating with the help
of the hose clamp.
77
1.5 MANUAL CHECKING AND
ADJUSTING V-BELT TENSION
1.5.1 Checking V-Belt Tension
General
The generator and air blower are driven by a V-belt. The loads created by
these two accessory units impose considerable stresses upon the belt at high
engine speeds and, especially, during downshifts. For this reason, we recommend that the V-belt tension be frequently checked and adjusted when
necessary.
Loose V-belt tension results in belt slippage in the pulley causing the engine to
run hot.
excessively high V-belt tension leads to belt failure and, possibly, premature
wear of the generator bearings.
78
When servicing the engine, care should be excercised to keep oil and grease
off the V-belt; oily V-belts should be washed in a soap or detergent solution
and then thoroughly rinsed in clear water although it is always of advantage in
such cases to install a new belt. V-belts contaminated with oil or grease for any
length of time are usually no longer serviceable and must be replaced. When
correctly adjusted, the V-belt can be deflected by 15-20 mm (5/8 - 3/4 in.)
under slight thumb pressure applied midway between both belt pulleys. The
belt should not show any signs of wear such as frayed edges or split flanks.
79
1.5.2 Adjusting V-Belt Tension
Note
New V-belt will stretch after a short time of use so that they no longer have
the proper tension after 50 - 100 km (30-60 miles). For this reason it is
absolutely necessary to recheck the belt tension of new belts within a short
period subsequent to the installation.
Attempts to remove the V-belt by means of a screwdriver, without loosening
the generator pulley, will result in damaged V-belt and pulley.
•
•
1. Remove generator pulley retaining nut (36 mm wrench); to lock the
pulley in place during this procedure, insert a square-edged screwdriver
into the recess in the inner edged of the pulley and brace, it .against the
top bolt protruding from the generator housing.
2. Remove outer pulley half.
80
Adjusting V-Belt Tension
•
•
•
•
3. Arrange spacers between pulley halves as needed. The belt tension
should be so adjusted, by adding or removing spacers between the two
pulley halves, that the belt will yield by about 15-20 mm (5/8 - 3/4in)
under light thumb pressure. Removal o|.ipacers increases the belt
tension, addition of spacers decreases the tension (see Fig. 72). If the
belt has streched or worn to such extent that only one spacer remains
between the pulleys at correct belt tension, it should be replaced since
the condition will result in insufficient cooling due to decreased impeller
speeds. In addition, it should be noted that the belt does not ride at the
pulley root, that is, on the pulley spacers.
4. Mount outer pulley half.
5. Spacers not inserted between the two pulley halves should be placed
onto the shaft between the outer pulley half and the nut so that all
spacers remain on the pulley hub.
6. Tighten pulley retaining nut. Loose pulley halves will quickly become
defective in their seats and also cause a rapid V-belt wear. Damaged
pulley halves must be replaced.
81
1.6 DESCRIPTION OF THE 912 (356
B/T6) HEATING SYSTEM
1.6.1 Functional View of the Heating
System (Germany and Sweden)
Due to varying laws in force, it is necessary to equip The Type 912 cars with
two different heating systems. Cars manufactured for sale in Germany and
Sweden are equipped with a modified heating system known as 356 B/T6
whereas all other Type 912 export cars continue to be equipped with the wellproven and reliable Export-type heating system. The difference between the
two systems is that in the 356 B/T6 system the air required for heating is
drawn from the air blower housing and ducted to the passenger compartment
through the heat exchangers, without passing through the engine cooling
cycle. In the Export-type heating system the cold air performs its engine
cooling function and, already preheated, is ducted into the heat exchanger and
on to the passenger compartment. The desired effectiveness of both heaters is
achieved through the use of appropriately designed heat exchangers.
82
1.6.2 Functional Description
The entire fresh air mass enters through slots in the engine compartment lid
(1), being drawn in by the cooling air blower. Part of the fresh . air mass
required for heating the passenger compartment is diverted from the cooling
air blower (2) into a separate duct (3),
The fresh air (outside air) flows from the supply duct through the two heat
exchangers (4) at the engine. The heat exchangers consist of sheet- metal
jackets which enclose the exhaust pipes (5). All detachable and welded joints
of the exhaust system (6) are located outside the heat exchangers.
The entire engine exhaust system as well as most part of the engine, such as
the crankcase and cylinders, is located in the free-air stream beneath the rear
section of the car.
The heating air flows from both heat exchangers' through connecting hoses
(7), air gates (8), guide ducts (9), and silencers (10) which are situated within
the longitudinal chassis support members, to heat outlets arranged in pairs.
Heat outlets are provided as follows:
For defrosting the windshield (11) and the rear window (12) by way of
defroster nozzles. For the forward leg area (pedal area) by way of sliding gates
(13) located alongside the longitudinal chassis supports next to both seats.
The air gates (8) are so designed as to permit a continuous flow of air through
the heat exchangers (over the exhaust pipes) regardless whether the heat is
turned on or off.
In addition, outside air may be let in through the ventilating system (14) in
front of the windshield independently of the cars heating system. Hot air for
preheating the carburetors is taken from the hot air stream.
83
1.6.3 Operating description:
Heater Control
The heat is controlled through a control lever (15) located in front of the
gearshift lever.
With the lever moved back, the heater is open, and with the lever moved
forward, the heater is closed.
Through the lever action, air gate flaps are moved in the air gate assembly (8)
by way of a cable connection. Should the cable break, the two flaps shut
automatically and the hot air is permitted to flow outside.
84
Located in the forward leg area, along the right and left sides adjacent to the
front seats, are sliding gates (13) with which it is possible to regulate the flow
of hot air to the leg area. When the slider is moved forward, the flow of air
stops although in that case the entire warm air supply enters the passenger
compartment through the defroster nozzles (11 and 12).
85
86
1.6.4 Bottom View of Vehicle
Bottom view of Vehicle. Heater Type 356b/T6.
3. Transmission
6. Oil strainer cover
7. Engine crankcase
8. Exhaust muffler
10.
11.
Heating air control gate
12.
Axle shaft
13.
Shockabsorber
14.
Heat exchanger
15.
Tail pipe
87
1.6.5 Description of the Export Type Heating System
1.6.6 Functional View of the Heating
System
Functional Description
The entire fresh air mass enters through slots in the engine compartment lid
(1). being drawn in by the cooling air blower (2). The air blower forces the air
over the cylinders (3) where it is preheated, and on to the lower air ducts.
When the heater is shut off, the air flows directly outside. When the heater is
turned on (control lever -15- moved back), the air flows through a heat jacket
into connecting hoses (8), dueling pipes (9), and silencers (10) into the
passenger compartment. The following hot air outlet pairs are provided:
Windshield defrosting nozzles (11)
Rear window defrosting nozzles (12)
Leg area outlets through sliding gates (13) located adjacent to the front seats.
In addition, independently of the car's heating system, ventilating outside air
may be let in through the ventilating system (14) in front of the windshield.
When the heater is on, warm air enters the engine compartment through
outlets (5). This warm air prevents carburetor icing and undercooling of the
engine. The flow of air into the engine compartment is controlled by a
thermostat.
Operating Description:
See description of 356B/T6 heater
Bottom View Of Vehicle - Export - type Heater. ...More
88
1.6.7 Bottom View of Vehicle - Export
Type Heater
3. Transmission
6. Oil Strainer cover
7. Engine crankcase
8. Exhaust muffler
10.
11.
Axle shaft
12.
Heating air control gate
13.
Shockabsorber
14.
Lower air duct for heater
15.
Tail pipe
89
1.7 REMOVING AND INSTALLING
EXHAUST MUFFLER
This procedure refers specifically to the German/Swedish version of the
heating system.
1.7.1 Remove Clamps from Heat
Exchangers
•
•
1. Remove both supports for engine rear shield.
2. Loosen the four exhaust pipe clamps behind the heat exchangers.
90
1.7.2 Remove Muffler
•
•
3. Loosen and remove supporting straps in the center of the muffler.
4. Pull muffler back to remove, loosening stuck pipe connections through
light tapping with a rubber mallet.
1.7.3 Installation
Installation is accomplished in reversed order, of the above by noting the
following points:
•
•
•
•
•
1. Inspect muffler and exhaust pipes prior to installation for leaks or
possible damage.
2. Straighten flattened or bent pipes. The welded joint between the
muffler and the rear exhaust pipe is particularly exposed to collision
damage. Exhaust gases escaping through any cracks at this point can
enter the engine compartment and with the heater on, the car's interior.
3. Use new gaskets.
4. Ensure that a good gas-seal is achieved at the front pipe connecting
points. If the mating flanges are not straight, straighten prior to
installation.
5. With the engine installed, the exhaust muffler must not touch the
body,
91
1.8 ENGINE LUBRICATION SYSTEM
Oil Circuit Diagrams
1.8.1 Oil Circuit in Cold Engine
1. Rocker arm
2. Pushrod
3. Piston
4. Valve lifter
5. Oil suction tube
6. Pressure relief valve
7. Bypass valve
8. Camshaft
9. Crankshaft
10.
Oil pump
11.
Counter-pressure line
12.
Oil line to Bearing 4
13.
Oil temperature sensor
14.
Oil pressure switch
15.
Oil cooler (repositioned back in sketch for better view)
16.
Bypass oil filter
92
1.8.2 Oil Circuit at Operating
Temperatures
Description of the Oil Circuit
The oil pump (10) draws cold oil from the crankcase sump and forces it to the
bypass valve (7) which opens at a pressure of approx. 1.3 atm (19 psi), i. e.,
the piston of the bypass valve is forced down, thus clearing a passage which
leads directly to the lubricating points by bypassing the oil cooler (15). The
pressure relief valve (6) in the crankcase opens when the pressure rises above
approx. 2. 9 atm (42 psi) and dumps the oil excess into the crankcase oil
sump.
As soon as the oil galleries have filled with oil and the oil pressure has
stabilized, a pressure rise equivalent to the pressure in the rest of the system
also occurs in the counter-pressure line (11) and under the bypass valve (7).
thus equalling the pressure exerted upon the bypass valve from the side of the
pump (10). The pressure relief valve (6) limits the oil pressure in the system
to 3 atm (44 psi). The mechanical spring in the bypass valve exerts a pressure
equivalent to approx. 1.3 atm (19 psi). Since equal oil pressure now prevails at
both ends of the bypass valve, the mechanical spring is able to expand and,
so, move the bypass valve up.
As the bypass valve (7) moves up, it'blocks the direct passage and causes the
oil to flow through the oil cooler before reaching the lubricating points
93
Oil Strainer
1.8.3 Removing Oil Strainer
•
•
•
1. Remove hex nuts from oil strainer cover.
2. Remove oil strainer cover.
3. Remove oil strainer and gaskets.
1.
2.
3.
4.
5.
Oil drain plug
Gasket
Oil strainer
Gasket
Oil strainer cover with magnetic filtering element
94
Install
Installation is accomplished in reversed order of the above by noting the
following points:
1.
2.
3.
4.
Check oil suction tube for proper positioning.
Clean oil strainer and remove gasket remnants.
Use new gaskets on both sides of the oil strainer.
Insert oil strainer making sure that the orifice in the strainer has a close
fit around the oil suction tube.
5. Remove gasket remnants from the oil strainer cover. Straighten the
cover if it is warped or bent, otherwise a good oil seal cannot be
expected.
6. Clean magnetic filtering element.
7. Do not over tighten the hex retaining nuts, especially when using thicker
gaskets, since this may warp the cover.
95
1.8.4 Magnetic Oil Filtering
A magnetic oil filtering element has been included in the oil strainer cover to
provide for a better filtering of the oil. The element is situated in the center of
the oil strainer cover with the oil suction tube located within it. The oil first
passes through the oil screen and then flows through the magnetic filtering
element.
1.
2.
3.
4.
5.
6.
7.
8.
9.
Crankcase
Oil strainer
Magnetic filter
Oil suction tube
Stud
Oil strainer cover
Disc
Rivet
Gasket
96
1.8.5 Pressure Relief Valve
Special Tools: P 74 Socket attachment
General
The pressure relief valve is located in the crankcase and governs engine oil
pressure.
When encountering malfunctions in the engine lubrication system, and always
in cases of leaks in the oil cooler, check the pressure relief valve for proper
functioning.
The bypass circuit valve is located in the timing gear cover and ensures
immediate lubrication of engine bearings and other points when the engine is
started.
97
1.8.6 Bypass Valve
The purpose of the bypass valve in the timing gear cover is to provide instant
lubrication for points in the engine, by bypassing the oil cooler, when the
engine is started.
1.
2.
3.
4.
Oil gallery to oil cooler
Oil gallery from oil pump
Oil gallery to lubricating points by bypassing the oil cooler
Opening for counter-pressure oil line
98
1.8.7 Bypass Valve at Start Up
When the engine is not running, the valve (plunger) closes the passage to the
lubricating points. As soon as the engine begins to run, the oil pump sucks oil
from the oil sump in the crankcase and forces it to the bypass valve. The
bypass valve is then forced down, under the pressure of the oil, and opens the
oil gallery to the lubricating points by bypassing the oil cooler.
99
1.8.8 Bypass Valve When Running
As soon as the oil pressure has built up, some of the oil flows through the
counter-pressure line to the cavity under the valve plunger equally
counteracting the pressure exerted by the oil from above, permitting the
mechanical spring to expand and, thus, push the valve plunger up and close
the oil gallery of the direct lubricating circuit. This forces the oil to flow through
the oil cooler before it can reach the lubrication points within the engine.
100
1.8.9 Removal Cap Screw
1. Remove cap screw with tool P 74.
2. Withdraw spring and valve plunger; if plunger is stuck, it can be
removed with an M 10 thread tap.
101
1.8.10 Withdraw Spring and Plunger
2. Withdraw spring and valve plunger; if plunger is stuck, it can be removed
with an M 10 thread tap.
Installation
following points:
1. Inspect valve plunger and plunger bore in housing for traces of seizure
(scratches, etc.). Carefully smoothen the surfaces, replace if necessary.
2. Check mechanical spring
3.
4.
5.
6.
Pressure Relief Valve and Bypass Valve Spring
Free length............ 66 mm (2.6in)
Wire diameter......... 1.4 mm (.055in)
Tension at 49 mm(1.93in).....4.7 kp (10.3 lbs) +/- 7%
7. Install new gasket washer.
8. Insert the piston so that its hollow end faces towards the cap screw.
9. To prevent scratching the bore in the housing, make sure that the spring
end does not ride in the plunger bore in housing.
102
1.8.11 Remove Oil Cooler
•
•
1. Remove air blower housing.
2. Unscrew oil cooler retaining nuts with a box wrench. ..
103
Remove Oil Cooler
•
3. Remove oil cooler and gaskets.
Installation
following points:
1. Check oil cooler for leaks and proper tightness of retaining nuts (test
pressure is 10 atm-147 psi).
2. If oil cooler is leaking, check pressure relief valve.
3. Use new gaskets.
104
Oil Pump
1.8.12 Remove Oil Pump
1. Remove
ducts.
2. Remove
3. Remove
4. Remove
5. Remove
engine rear shield and intermediate shield between the air
crankshaft pulley.
crankshaft pulleys shield,
oil pump cover.
oil pump gears.
105
Installation
Follow reversed order
1. Inspect oil pump housing, especially gear seating areas, for wear. Wear
within the housing will result in decreased oil pressure.
2. Inspect pump gears for wear. Gear flank clearance should be O.03 O.O5 mm (.001 - .003in.). Axial play of gears in the housing, with gasket
but without preload, is 0.035 - O.10 mm (.0014 - 0039in.). Wear limit
0.20 mm (. 0079in).
3. Check shaft of driven gear for firm seating in the housing.
4. Check sealing surface for oil pump cover (a t crankcase) for cleanliness.
5. Place a straight edge across the face of the pump gears. Using a feeler
gauge, measure clearance between the cover mounting flange in housing
and face of gears, which should be 0.06- 0.l28 mm (. 0024 - .0050in).
6. Use a new,- genuine gasket (0. 20mm = . OO8in) without applying
gasket paste. Gasket thickness in excess of specification will result in
decreased oil pressure.
106
Bypass Oil Filter Cartridge
1.8.13 Changing Bypass Oil Filter
Bypass oil filter cartridges used in Porsche cars cannot be cleaned and have to
be replaced when contaminated (normal replacement after every 10,000 km or
6,000 miles).
1.
2.
3.
4.
5.
6.
7.
Unscrew filter cover retaining bolt.
Withdraw filter cover.
Withdraw filter cartridge with a slight turn.
Remove oil from filter housing (use a suction pump).
Clean filter housing interior (do not use shredded rags).
Insert new cartridge by turning it slightly.
Insert new gasket into housing cover, properly position the cover on the
housing. depress, and tighten securely.
8. Check engine oil level.
9. Allow engine to idle for a few moments.
10.
Check for oil leaks in filter housing body and oil line connections.
11.
Recheck engine oil level.
12.
Replenish engine oil to the top mark on the oil dipstick (use
premium. grade HD oil).
107
1.9 HEADS
Remove and Install Rocker Arm
Carrier
1.9.1 Removal Rocker Arm Carrier
•
•
1. Remove rocker box cover.
2. Remove the 7 hex nuts (SW 13) from the rocker arm shafts.
108
1.9.2 Remove rocker arm shafts
•
•
3. Withdraw rocker arm shafts with rocker arms, springs, washers and
spacers.
4. Remove the three rocker arm carrier retaining bolts (SW 15 mm) and
withdraw carrier.
109
1.9.3 Rocker Arm Installation
following points:
1. Inspect retaining bolts for defects. Coat threads and base of bolt heads
with graphite oil. Use new spring washers,
2. Tighten retaining bolts to 5 mkp (36 lbs/ft).
110
1.9.4 Tighten the Rocker Arm Shaft
Nuts
•
•
3. Tighten the 7 rocker arm shaft retaining nuts (SW 13) to 2,5 mkp (18
Ibs/ft).
4. Adjust valve clearance.
Reoil shafts and rocker arms, install rocker box cover.
111
1.9.5 Disassembling and
Reassembling Rocker Arm Carrier
Disassembly
1. Remove the 7 hex nuts (SW 13) from the rocker arm shafts.
•
•
2. Withdraw rocker arm shafts with rocker arms, springs, washers, and
spacers.
3. Remove valve adjusting screws.
Reassembly
Reassemble the rocker arm carrier in reversed order of the above by noting
the following points:
•
•
•
•
•
1. Inspect rocker arm shafts and rocker arms for defects. Replace parts
showing traces of wear or damage.
2. Inspect valve adjusting screws for defects. Replace screws which have
strained threads or damaged ball joint sockets.
3. Check adjusting screws and rocker arms for unobstructed oil flow.
4. Arrange the spacers and / or thrust washers in such way that the
rocker arms strike the valve shafts approximately in the center of the
shaft butt, and that the pushrods do not come in contact with the
pushrod tubes.
5. Make certain that the washers, springs, and spacers are properly
arranged.
112
1.9.6 Remove Cylinder Head
Special Tools
•
•
VW 157 Allen wrench adapter
VW 118 Torque wrench
Removal
This section assumes the engine is removed.
1. Remove lower air duct, side shield, cylinder shrouds, intake duct and
carburetor.
113
2. Remove rocker box cover and unbolt rocker arm carrier.
3. Remove cylinder head retaining nuts with A Allen wrench adapter (the 8
A Allen nuts are shown above and below the valve stems in the illustration
above); remove washers located between the nuts and cylinder head.
4. Withdraw cylinder head.
Installation
following points:
•
•
1. No gasket is used between the cylinder head and cylinders.
2. Insert push rod cover tubes. To ensure proper sealing at the tube
ends between crankcase and cylinder head. the tubes must have the
required length at assembly, that is, used tubes must be stretched at the
bellows. The stretching should be accomplished with care so as to
prevent possible cracking of the metal.
114
1.9.7 Position Cylinder Deflectors
•
3. When installing the cylinder head make sure that the new a-rings at
the cover tube ends are properly seated; position the tubes weld seams
up.
o
o
•
•
•
•
a) Sealing points in crankcase.
b) Sealing points in cylinder head.
4. The cover tube O-rings are trapezoidal in cross-section.
5. Prior to installation, lubricate 0 -rings used under the cylinder head
nuts located within the rocker box.
6. O-rings should not be coated with gasket compound.
7. Ensure proper positioning of cylinder deflector baffles (compare profile
of recess for cap nut and one for hex bolt).
115
116
1.9.8 Torque the Head Bolts
•
8. Place 1 washer under each cylinder head nut situated outside the
rocker box.
•
9. Coat cylinder head nuts with graphite paste tighten lightly. then
torque to 1 mkp (7. 2 lbs/ ft) in sequence shown in the illustration.
10. Torque cylinder head nuts to 3 mkp (21.7 lbs/ft) in sequence shown
in the illustra tion.
•
•
117
1.9.9 Install Pushrods
•
11. Pump oil into pushrods until it comes through at other end, and
insert into pushrod cover tubes so that one end seats in the valve lifter.
118
1.9.10 Install Rocker Arms
•
•
•
12. Install rocker arm carrier, torque retaining bolts to 2.5 mkp (18.1
lbs/ft).
13. Install rocker arms.
14. Torque rocker arm shaft retaining nuts (SW 13 mm) to 2.5 mkp (18.
1Ibs/ft).
119
1.10 VALVES
1.10.1 Adjust Valves
•
•
15. Adjust valve clearance.
16. Mount rocker box cover.
Note
When installing the cylinder head make absolutely sure that the cylinders are
properly seated in the cylinder head. If a misaligned cylinder head is tightened,
it will most likely warp to the extent of being no longer useable.
120
1.10.2 Removing and Installing Valve
Springs
Special Tool
Use special tool P7 for removing and installing valve springs.
Checking valve springs:
Free length
47 mm (1,85in)
Wire diameter
4.5 mm (. 177in)
Spring tension with spring compressed to 41
mm (1. 61in)
36kp(79, 3lbs) +/- 5kp(3,
321bs)
Spring tension with spring compressed to
30.15 mm (1.19in)
97kp( 213, 21bs)+/- 2. 5k p(
5. 51lbs)
Spring tension variations up to 50% are permissible in used springs.
All valve springs used in one engine must be of equal free length since the length
affects springing characteristics.
Checking Installed Length
Note:
Intake and exhaust valve springs are of the same length. The installed spring length is
changed or adjusted through the addition or removal of spacers located under the
springs.
Important:
The valve springs must always rest on the steel washer and never on the spacers
since the spring could damage the spacers.
1. Install- special tool P 10 with the respective spring retainer and both valve
keepers.
2. Determine the indicated value and correct it, if necessary. by adding or
removing spacers.
3. Install valve springs so that the closely wound coils rest on the 1,5 mm thick
washer (see note, above).
Installed length of valve springs is:
Intake = 41,0 mm (1.61in)
Exhaust = 40,5 mm (1.59in)
Note:
Valve springs made by various manufacturers are supplied under the same spare part
number. However, all springs (progressive or linear coils) may be paired in one
engine.
121
1.10.3 Valve Spring
Note:
Intake and exhaust valve springs are of the same length. The installed spring
length is changed or adjusted through the addition or removal of spacers
located under the springs.
Important:
The valve springs must always rest on the steel washer and never on the
spacers since the spring could damage the spacers.
1. Install- special tool P 10 with the respective spring retainer and both
valve keepers.
2. Determine the indicated value and correct it, if necessary. by adding or
removing spacers.
3. Install valve springs so that the closely wound coils rest on the 1,5 mm
thick washer (see note, above).
Note:
Valve springs made by various manufacturers are supplied under the same
spare part number. However, all springs (progressive or linear coils) may be
paired in one engine.
a = Installed length
b = Steel washer
c = Spacers
Installed length of valve springs is:
Intake = 41,0 mm (1.61in)
Exhaust = 40,5 mm (1.59in)
122
1.10.3 Checking Valve Guides for
Wear
Special Tools: P 21b Valve guide plug gauge
See:
Replacing of valve guides see 35 EN.
Clearance between valve guide bore and valve stem is:
Intake = 0.035 - 0.060 mm ( 0.0014in to 0.0024in)
Exhaust = 0.055 - 0.080 tnm (0.0022in to 0.0031in)
Valve guide bores should be measured with a valve guide plug gauge of 10
mm diameter (.394in).
When installing the sealing caps, it should be noted that first the valve is
pushed into the valve guide and then the sealing cap pulled over the valve
guide until the base of the cap comes to rest against the valve guide.
123
1.10.4 Checking and Reconditioning
Valve Seats
Special Tools
•
•
P 11 Valve seat cutter handle with 10 mm dia. cutter guide
P 12 Eight-piece valve seat cutter set.
Checking
1. Check valve guides for firm seating in the cylinder head.
2. Check valve seating using machinists blue.
3. Inspect valve seat surface. If the valve does not seat on the whole seat
surface, lightly rework the seat with a cutter.
4. Valve seating may be checked with the valves installed in the cylinder
head by pouring some gasoline into the respective port.
Check the Valve Seats
Valve seat width
Intake 1.25 +/- 0.15 mm (0.050 +/- 0.006 in.)
Exhaust 1.55 +/- O. 15 mm (0.061 +/- 0.006 in.).
Valve seats showing traces of wear or pitting may be refaced providing that
the permissible width of the 45 deg. seat can be maintained, and the 25 deg.
bevel in the outer circumference does not exceed the outer diameter of the
valve seat insert. If this is not possible, the cylinder head must be replaced. It
is not p~sible to replace the yalve seat inserts with the equipment at hand in
normal workshops.
124
45 degree Cut
1. 45 deg seat cut:
The 45 deg cut must be performed with particular care to produce a smooth
surface free of chatter marks. It is very important to apply pressure from
directly above. Removal of base metal must be held at a minimum so as not to
render the valve seat insert prematurely unusable. The cutting procedure
should be discontinued as soon as the cutter has cleaned the entire seat area,
75 Degree Cut
2. 75 deg bevel cut: Lightly bevel the lower edge of the valve seat using the 75
deg. cutter.
125
25 Degree Cut
3. 25 deg bevel cut: Using the 25 deg. cutter, bevel the upper edge of the seat
until the specified seat width is obtained.
126
Refacing Valves
Valves showing face wear of a degree that cannot be corrected through
lapping, may be dressed on a valve refacing machine. Refacing of the valves
must be accomplished with appropriate care. Particular attention should be
devoted to the fact that only so much of the base metal is taken off as is
required to produce a clean valve face. The valve stem must, in no way, show
traces of contact with the dressing wheel; valves with stems touched by the
dressing wheel must not be installed.
Valve dimensions
Intake
Exhaust
A
37. 9 - 38. 1 mm (1.492 - 1.500 in.)
33. 9 - 34.1 mm (1.334 - 1.342 in.)
B
117.9 mm (4.630 in.)
128.5 mm (5.060 in.)
C
9.98 - 9.99 mm (.3929 - .3933 in.)
9.96 - 9.97 mm (.3921 - .3925 in.)
b
1.7 - 2.3 mm (.067 - .091 in. )
2.0 - 2.3 mm (.079 - .091 in.)
127
1.10.5 Seating, Inspecting and
Testing Valves
Seating Valves
Special Tools:
P 9 Suction cup, for turning valve The following points should be observed
when seating (lapping) valves:
Lapping
The following points should be observed when seating (lapping) valves:
1. Seat valve with the P 9 suction cup.
2. Use fine-grain grinding compound to prevent roughness or "grooving".
3. Upon completion of lapping, fully remove all grinding compound
remnants.
Note:
The grinding compound is water-soluble and should not be exposed to oil or
grease. A special effort should be made to thoroughly clean and flush with
water all involved component parts of the engine, including the valve guide
bores, and then to dry and oil these prior to reassembly.
Inspecting Valves
1. Clean valves from carbon deposits.
2. Inspect valve face for wear or pitting. If necessary. reface on dressing
machine. When refacing the valves, make certain that --especially in the
case of the thermally higher stressed exhaust valves- - the dimension b
(see Fig. 123) is not exceeded.
3. Valve stems showing excessive wear (ridge formation) must be replaced.
4. Valves with warped stems, traces of seizure, or damaged valve keeper
seats must be replacad. Valve stems cannot be reground or straightened
for any reason.
Testing Installed Valves For Leakage
Installed valves may be tested for leakage by pouring some gasoline into the
respective port. Properly seated valves will not permit gasoline to pass
through.
128
1.10.6 Adjusting Valve Clearance
Valve clearance (cold) is:
Intake
Exhaust
0.10 mm (0.004 in)
0.15 mm (0.006 in)
General:
Excessive clearance causes valve noise and decreased power.
Insufficient clearance results in decreased power, valve overheating or
burning, and carburetor flashback which may cause a carburetor fire.
We therefore recommend that the valves be adjusted in a reputable shop.
The valves should be adjusted when the egine is cold.
The best sequence to follow is Cyl. 1, 2, 3, and 4 while rotating the crankshaft
counterclockwise.
Prior to adjusting, position the piston on top dead center (TDC) on
compression stroke since both valves are closed at that point. If adjustment
begins with Cyl. 1, turn crankshaft counterclockwise until both valves are
closed and the "OT" (TDC) mark on the crankshaft pulley is lined up with the
mark on the crankcase.
Adjusting:
•
•
1. Remove both rocker box covers (engine cold).
2. Remove distributor cap.
129
Adjusting Valve Clearance
•
•
•
1. Remove both rocker box covers (engine cold).
3. Turn crankshaft counterclockwise- -using a box wrench on the
crankshaft pulley, if necessary-- until the "OT"-mark on the pulley has
lined up with the mark on the crankcase. At this point, the distributor
rotor will be pointing towards a notch machined into the distributor
housing.
130
Adjusting Valves
Valve clearance (cold) is:
Intake
0.10 mm (0.004 in)
Exhaust 0.15 mm (0.006 in)
•
•
•
•
•
4. Check valve clearance at Cyl. 1.
5. Loosen lock nut on adjusting screw.
6. Adjusting clearance by turning the screw while simultaneously
checking the clearance with a feeler gauge.
7. Hold adjusting screw in position when tigtening the lock nut.
8. Recheck clearance.
131
1.10.7 Checking Valve Timing and
Clearance
Normally the valve clearance should be checked or adjusted when the engine
is cold at an outside air temperature of approx. 20 deg C (68 deg F). The valve
clearance is as follows:
Intake valves 0.10 mm (0.004 in)
Exhaust valves 0.15 mm (0.006 in)
Valve clearance should be checked a t regular intervals and appropriate care.
The following malfunctions can be caused by wrong valve adjustment:
Insufficient clearance:
Burnt or pitted valves and seats.
Warped valves.
Unevenly running engine.
Valve timing off
Excessive clearance:
Valve noise
Increased wear in valve components
Unevenly running engine
Valve timing off
Proper valve adjustment results in a well running engine only when the valves
are seating well, the valve guides are not worn, and the valve stem ends are
not pounded in or otherwise worn.
Valve timing points:
Intake opens before TDC
17 deg
Intake closes after BDC
53 deg
Exhaust opens before BDC
50 deg
Exhaust closes after TDC
14 deg
Note :
The above timing points are established with 1.00 mm valve clearance in cold
engine. When valve timing has been checked, reset valve clearance to normal
specifications.
Lapped or refaced valves and seats seat faster than normal. For this reason,
set valves with an additional 0.15 mm (0.006 in) clearance over the specified
value for a test run of at least one-half hour.
When the test run has been completed, or before testing engine performance,
readjust valve clearance to normal values.
132
1.10.8 Removing and installing Valve
Guides
Punch out the Valve Guides
1. Drill valve guides with a 12 mm (0.427 in) drill to loosen in their
seats.
2. If a heating oven is available. the guides need not be drilled but,
instead, the head heated to approx. 180 deg C (356 deg F),
3. Using a punch of proper size (see illustration), drive the valve
guides out towards the combustion chamber.
Installation
The valve guide receiving bores in the cylinder head will have widened
somewhat during the removal Consequently. oversized valve guides will have
to be used and properly fitted into the head.
1. Precisely measure the valve guide receiving bores in the head.
2. Machine the oversize valve guides on a lathe to bring to outside diameter
matching that of the bore in the head. The required preload for the in take and
exhaust valve guides is 0.041 - 0.06 mm (0.0016 - 0.0024 in).
3. Press the valve guides into the cylinder head from the rocker arm side. Use
tallow for lubrication.
4. Ream the guides with a broach reamer or a precision drill to a diameter of
10 mm E7.
If necessary, the valve guides may be reamed with a conventional reamer.
133
1.10.9 Removing and installing Valve
Seat Inserts:
1. Using a portable electric grinder, grind through a valve seat insert so that it
loosens in its seat.
2. Drive the old seat insert out.
3. Precisely measure the seat receiving bore in the head.
4. Machine the oversize valve seat inserts on a lathe to bring to outside
diameter matching that of the bore in the head.
The required preload is as follows:
Intake valve insert: 0.15 - 0.19 mm (0.006 to 0.0075 in)
Exhaust valve insert: 0.10 - 0.15 mm (0.004 to 0.006 in)
5. Heat cylinder head to approx. 200 deg C (392 deg F).
6. Using an appropriate driver, drive the valve seat insert into place.
7. Allow the cylinder head to slowly cool to room temperature.
Table of Dimensions for Valve Guide Installation
(l mm = 0.03937 in)
Valve Guide
Size
Valve Guide Outside
Dia.
Diameter of Receiving Bore in
Cylinder Head
Standard
14,048 - 14,059 mm
14,000 - 14, 008 mm
1st oversize
14, 248 -14,259 mm
14,200 - 14,208 mm
2nd oversize
14,448 - 14,459 mm
14,400 - 14,408 mm
Table of Dimensions for Valve Seat Insert Installation
Insert Size
Insert Outside
Diameter
Diameter of Receiving Bore in
Cylinder Head
Standard (intake)
41,182 - 41,198
mm
41,000 - 41,025 mm
1st oversize
(intake)
41,502 - 41,518
mm
41,328 - 41,352 mm
Standard
(exhaust)
37,120 - 37,140
mm
36,990 - 37.020 mm
1st oversize
(exhaust)
37,680 - 37,700
mm
37,550 - 37.580 mm
134
1.11 CYLINDERS
1.11.1 Reconditioning and Exchange
of Cylinder Heads
General
Cylinder heads with worn valve guides, valve seats. or spark plug inserts may
be sent to the factory for reconditioning.
When the cylinder heads are being reconditioned, the combustion chamber
displacement is measured and so indicated in cubic centimeters.
Make sure that cylinder heads used in one engine have the same combustion
chamber displacement (permissible deviation is +/- 1 cc).
1.11.2 Check Cylinder Head
Displacement
Reworked cylinder heads must be checked for combustion chamber
displacement and the appropriate value stamped into the head. Should it be
not possible to send the cylinder heads back to the factory for overhaul, the
job may be performed locally providing that the required equipment is at hand.
135
1.11.3 Removing and Installing
Cylinders
Special Tool
P 8a Piston ring compressor, 82.5 mm diameter.
Removal
1. Remove rocker arms and rocker arm carrier, Remove valve pushrods and
mark for reassembly.
2. Remove cylinder head and push rod cover tubes (25 En).
3. Withdraw cylinders, mark 1 through 4 as appropriate.
136
Cylinder Installation
following points:
1. Check cylinders for wear, if necessary replace together with pistons of same
size group.
2. The cylinder seat in crankcase and cylinder head must be clean at time of
installation since dirt particles lead to cylinder distortion. Using a straight edge,
check cylinder seats in crankcase for linear alignment of seating surfaces in
relation to each other and, upon insertion of cylinders into crankcase, check
alignment across the top of cylinders.
3. Use new gasket rings a t base of cylinders.
4. Check and oil pistons and piston rings. Ensure that piston rings are installed
in appropriate locations (check "TOP" markings).
5. Stagger piston ring gaps 12 deg. apart with oil control ring gap facing up,
compress rings wi th piston ring compressor.
6. Lightly oil cylinder bores and push onto pistons, Visually check the required
clearance between the cylinder stud bores and studs, The studs must not touch
the cooling fins. Clearance can be determined by turning the cylinders in their
bases, If necessary, straighten studs.
7. Install pushrod cover tubes. Do not fail to install deflector baffles and
supporting springs.
8. Tighten cylinder head nuts to 3 mkp (21. 7 lbs/ft) by following proper
sequence.
137
1.11.4 Inspecting Cylinders
Special Tools:
P 13c Cylinder gauge setting ring
Standard Size
(Note: 1 mm = 0,03937 in)
Group
Cylinder Diameter
Piston Diameter
-1
82,485 - 82,494
82,47
0
82,495 - 82,504
82,48
+1
82,505 - 82,514
82,49
1st Oversize
Group
Cylinder Diameter
Piston Diameter
-1 KD 1
82,985 - 82,994
82,97
0 KD 1
82,995 - 83,004
82,98
+1 KD 1
83,005 - 83,014
82,99
The above tables show which piston and cylinder size groups can be paired.
Wear limit is a clearance of 0,2 mm ( 0.008 in) between piston and cylinder.
Exact piston to cylinder clearance can be determined only by measuring each
component separately.
Measure cylinders at a point approximately 15 mm (3/4 in) below the cylinder
top using a bore micrometer with setting ring P 13c.
Replace cylinders which are worn close to the permissible wear limit.
138
1.11.5 Cylinder Marking
All cylinders are marked at the base to indicate the bore diameter group, such
as "0", or reconditioned units by "+ 1 KD I" etc.
The piston tops bear appropriate size values (+1 KD 1, etc),
The piston to cylinder clearance when new is 0.02 mm (0.0008 in), the wear
limit is 0.2 mm (0.008 in).
Cylinders worn close to the wear limit should be replaced together with
pistons; use cylinder / piston replacement sets falling into the appropriate size
group. Piston/ cylinder sets installed in one engine may not differ by more than
four size groups.
Note:
The Biral cylinders are available in four height groups; cylinder height is the
distance between the cylinder seating flanges at the crankcase and the cylinder
head.
Cylinders installed under one cylinder head must be of same height and bear
same identifying symbols at the cylinder base. The identifying symbol is a
triangle inside which the number 5, 6, 7, or 8 is stamped, depending on the
particular size group.
139
Pistons
Special Tools:
P 1a Electric piston heater P 2 Piston pin mandrel
General:
Install the Piston with the Arrow
toward the Flywheel
The piston pins are arranged in the pistons off the center and it is, therefore,
important to correctly install the pistons in the engine. The piston top bears an
arrow mark. When installed, the piston must be so oriented that the arrow
points in the direction of vehicle travel, i. e., towards the flywheel.
140
Off Center Piston Pin
Owing to the off-centered piston pin, the connecting rod shifts its direction of
attack, and so does the piston its tangential angle in relation to the cylinder
wall prior to reaching the top dead center (TDC). Since in this position the
combustion has not yet begun, the prevailing side forces are still small. which
permits the piston to shift onto the opposite cylinder wall softly rather than
with a slamming impact. As a result, piston slap noise occuring at time of the
pressure point shift is kept at a minimum, especially when the piston to
cylinder wall clearance is greater than normal.
141
1.11.7 Remove and Mark Cylinders
1. Remove cylinders.
2. Mark pistons to ensure reassembly in original position and location.
142
1.11.8 Heat Pistons
3. Remove piston pin retainers making sure they don't fall into crankcase.
4. Heat pistons to approx 80 deg C (175 deg F) using electric piston heater.
143
1.11.9 Remove Pins and Rings
5. Using the piston pin mandrel, drive piston pins out and remove pistons.
6. Remove piston rings (if necessary) using a piston ring expander. To avoid
breaking or bending the piston rings, expane! these as little as possible,
keeping rings close to the piston body.
144
1.11.10 Check Proper Size of Rings
1. Connecting rods must be in proper alignment.
2. Clean pistons. Remove carbon deposits from piston top and piston ring
grooves without scratching the base metal. Signs of uneven contact or carbon
deposits on one side of the piston may indicate poor connecting rod alignment.
3. Check piston rings for proper condition, ring gap, and ring groove clearance.
If not as specified, replace piston rings or pistons, as required.
4. Measure pistons. Size designation is stamped into each piston top.
Measurements are accomplished as shown in the illustration (perpendicular to
piston pin axis).
Piston size groups are shown in tables. Piston clearance at installation is 0.02
mm (0.0008 in). If the measurement of the piston and cylinder reveals a
clearance approaching the wear limit, the piston and cylinder should be
replaced with a set falling into the same size group. If the mating cylinder of a
damaged piston does not show traces of wear or damage, it may be possible to
replace the piston alone with one falling into the appropriate size (letter)
group.
145
1.11.11 Check Ring Fit in Piston
5. Fit compression rings and oil scraper.
6. Check piston ring gap. This is done by inserting the ring into the cylinder
and pushing it down, somewhat. with a piston. then measuring gap with a
feeler gauge.
Applicable to all rings:
Ring gap 0.3 - 0.45 mm (0.012 - 0.018 in). Stagger piston ring gaps so that
they are approx. 120 deg apart.
Piston ring side clearance is specified in the Table of Tolerances and Wear
Limits (page E 95).
Piston rings must be installed with a ring expander to prevent piston damage
or ring breakage.
Piston rings must be installed in the piston so that the "TOP" marking on the
ring faces up, i. e., towards the piston top.
146
1.11.12 Install Piston Pins
7. Insert piston pin retainer on the flywheel side first.
8. Inspect and install piston pin. The piston pin is held in the piston through
interference fit. If the piston pin can be pushed into the cold piston by hand,
use a pin of larger diameter. A color code marking inside the piston on the
piston pin boss indicates the proper size of the piston pin, as follows:
white - 21. 997 -22. 000 mm
blue - 22.000-22,003 mm
Piston pin clearance in the connecting rod bushing is O. 020 - 0.036 mm
(0.OOO8 in to 0.0014 in). If the clearance a pproaches the wear limit of 0.050
mm (0.002 in), fit a new piston pin into a new connecting rod bushing.
Install the cold, oiled piston pin in the piston which has been heated to 80 deg
C (175 deg F) through immersion in hot oil or application of the e1ectric piston
heater, in which condition the pin should slide into the piston under light
pressure; the pin should be pushed through, to the pin retainer, in one
continued move.
9. Install second pin retainer. The pin retainers must fit well in their groove
within the piston pin boss.
147
1.11.13 Inspecting Pistons
Piston diameter is indicated by size group stamped into the
piston top. The individual size groups are shown in the
[html:/912/manual22.html piston size table]. Piston
measuring point is shown in Fig. 137.
In order to obtain precise measurement values, we
recommend the use of a fixed dial gauge which has been
preset with gauge blocks. Pistons showing evidence of seizure
or wear are no longer serviceable; however, if the mating
cylinder is in good condition, the fault can be rectified by
installing only a new piston of the appropriate size group or
letter designation.
Piston Measuring Points and Identification
Conspiculously broad bevel around the piston top perimeter.
Two compression rings above the piston pin, one oil scraper below the piston
pin.
Nominal diameter measuring point shown by arrow [html:/912/912_fig_137
(Fig. 137)].
148
1.11.14 Piston Measuring Points
Piston diameter is indicated by size group stamped into the piston top. The
individual size groups are shown in the piston size table. Piston measuring
point is shown in Fig. 137.
In order to obtain precise measurement values, we recommend the use of a
fixed dial gauge which has been preset with gauge blocks. Pistons showing
evidence of seizure or wear are no longer serviceable; however, if the mating
cylinder is in good condition, the fault can be rectified by installing only a new
piston of the appropriate size group or letter designation.
149
1.11.15Piston Size Table
Piston Size Groups
Piston Dia. +/- 0.005 mm
Stamped Marking
82,49
+1
82,48
0
82.47
-1
82,99
+ 1 KD 1
82,98
0 KD 1
82,97
- 1 KD 1
83,49
+ 1 KD 2
83,48
0 KD 2
83.47
- 1 KD 2
Size Group
Standard size
1st oversize
2nd oversize
Piston Pin Size Groups
Piston Pin Tolerance Category
Color Code
Spare Part Nr.
0,000 ... - 0.003 mm
White
616.103.321.01
0,000 ... + O.003 mm
Blue
616.103.321.50
150
1.12 CRANKCASE
Crankcase Disassembling and
Reassembling
Special Tools:
•
•
P 44 Hex socket (36 mm)
P 49 Retaining Springs
Disassembly
1.12.1 Crankcase Dissassembly
•
•
•
•
•
1.
2.
3.
4.
5.
Remove
Remove
Remove
Remove
Remove
oil drain plug.
oil cooler.
flywheel.
oil pressure switch.
oil pressure relief valve.
151
1.12.2 Remove Oil Pump
•
•
•
•
•
•
6. Remove oil strainer and magnetic filtering element.
7. Remove fuel pump insulating flange.
9. Remove crankshaft pulley and Woodruff key.
10. Remove pulley shield.
11. Remove oil pump
152
1.12.3 Remove Timing Gear Cover
•
•
153
1.12.4 Separate the Case
•
•
•
•
•
•
•
•
14.
15.
16.
not
the
17.
18.
19.
20.
21.
Remove crankcase retaining nuts.
Remove crankcase retaining nuts at camshaft end (flywheel side).
Withdraw right crankcase half using a rubber mallet if necessary. Do
pry with sharp tools, such as a screw driver, as this could damage
mating surfaces.
Remove valve lifters.
Withdraw camshaft and crankshaft.
Remove camshaft end cap.
Remove crankshaft oil seal at Bearing 1.
Withdraw Bearing 2 and 3.
154
1.12.5 Not Correct Position of
Timing Gears
Reassembly is accomplished in reversed order of the above by noting the
following points:
•
•
•
•
•
•
•
•
•
•
•
•
•
1. Inspect crankcase and timing gear cover for cracks or damage.
2. Using an appropriate solvent, remove sealing compound remnants
from crankcase mating surfaces.
3. Check mating surfaces for linear alignment and cleanliness.
4. A ssemble empty crankcase and tighten retaining nuts. Using an
inside micrometer, measure main bearing bores.
5. If necessary, lightly break the sharp edges from main bearings bores.
6. Flush oil passages with solvent and blow trough with compressed air.
7. Check oil suction tube for firm seating and tightness; if necessary,
refasten with P 50a ball end punch.
8. Check valve lifters and lifter guide bores.
9. Check firm seating of dowel pins aligning timing gear cover.
10. Insert main bearing dowel pins. Install main bearing inserts for
Bearing 2 and 3- place the insert half which has the oil passage into the
left crankcase half making sure that the passage in the insert lines up
with the passage in the crankcase bearing seat; install the other insert
halves in the right crankcase half.
11. Install crankshaft and camshaft, check for free rotation.
12. Install thrust washer, crankshaft oil seal and Bearing 1.
13. Note correct positioning of timing gears. (See Fig. 142).
155
1.12.6 Install Timing Gear Cover
•
•
•
•
•
•
•
•
•
•
•
•
14. Install camshaft end plug, seal with gasket compound.
15. Secure valve lifters with P 49 retaining springs.
16. Apply a thin, uniform coat of gasket compound to crankcase mating
surfaces, Make absolutely certain that no gasket compound enters oil
galleries of crankshaft and camshaft bearings.
17. Join crankcase halves.
18. Install o-rings and beveled washers fitted under cap nuts; position
the washers so that the inside bevel faces the crankcase to
accommodate the o-rings, Tighten cap nuts to 4 mkp (29 lbs/ ft),
19. Tighten crankcase retaining nuts at camshaft end (flywheel side).
20. Install timing gear cover.
21. Tighten remaining crankcase retaining bolts to 3 mkp (21. 7 lbs/ft).
22. Tighten timing gear cover retaining nuts to 2 mkp (14. 5 lbs/ft).
23. Install new oil seal at Bearing 4 in timing gear cover,
24. Turn crankshaft to check for free rotation.
25. Install fuel pump insulating flange and fuel pump.
156
Distributor Pinion Shaft R/R
1.12.7 Disconnect Distributor
•
•
•
•
•
•
•
•
2. Detach connecting wire from distributor.
3. Remove hex nut which holds distributor base plate.
4. Withdraw distributor.
5. Remove fuel pump, insulating flange, gaskets, and actuating plunger
(13 Fu).
6. Withdraw distributor. pinion shaft by pushing up and turning to the
left through orifice of fuel pump receiving flange.
7. Withdraw thrust washer from pinion shaft base in crankcase (Caution do not drop washer into crankcase interior).
8. Withdraw spring from pinion shaft.
157
1.12.8 Inspect and Install Pinion
Shaft Washer
Installation
following points:
•
•
1. Inspect fuel pump cam and shaft pinion for wear. If pinion shows
traces of wear, install new pinion shaft as well as distributor drive gear
(bronze) on crankshaft.
2. Inspect thrust washer at base of pinion shaft for wear, replace if
necessary (Caution - do not drop washer into crankcase interior).
158
1.12.9 Install Pinion Shaft
•
3. Position piston in Cylinder 1 on firing point TDC and insert pinion
shaft. The coupling slot in the pinion shaft is off center. When instal!ed,
the pinion shaft must be so positioned that the slot is directly
perpendicular to the longitudinal engine axis with the smaller section of
the pinion shaft top facing towards the crankshaft pulley.
159
1.12.10 Insert Spring in Pinion Shaft
•
•
•
•
•
4. Insert spring into pinion shaft with the help of a welding rod or a thin
screwdriver.
5. Install distributor.
6. Connect wire to distributor.
7. A djust ignition timing.
8. Mount distributor cap.
160
Removing and Installing Oll Seal at
Bearing 4
Special Tools
P 73 Installer for oil seal at Bearing 4
Removal
•
•
•
•
•
1. Remove crankshaft pulley (47 En).
2. Withdraw Woodruff key.
3. Deform old oil seal by striking it with hammer and punch through the
recess slot in the seal sea t, withdraw oil seal.
4. Withdraw oil deflector.
5. Remove burr, if any, from oil seal seat.
1.12.11 Install Bearing 4 Oil Seal
Fig 148
•
•
•
•
•
1. Insert oil deflector.
2. Install oil seal with P 73 installer.
3. Lubricate oil sealing surface on crankshaft pulley (smoothen if
necessary).
4. Insert Woodruff key.
5. Install crankshaft pulley.
161
Bearing 4 R/R
Special Tools
•
•
P 27 a Assembly plate for removing and installing Bearing 4
P 73 Installer for oil seal at Bearing 4
Removal
1.12.12 Deform Oil Seal
•
•
2. Deform old oil seal by striking it with hammer and punch through
recess slot in seal seat.
162
1.12.13 Pry Oil Seal
•
3. Pry old oil seal out with a screwdriver or similar tool.
163
1.12.14 Heat and Remove Bearing 4
•
•
•
•
4. Withdraw oil deflector.
5. Remove bearing set screw.
6. Remove burr. if any. from recess in oil seal seat.
7. Heat timing gear cover to approx. 60 deg C (140 deg F) and remove
Bearing 4 using punch P 27a of the assembly plate set.
164
1.12.15 Install Oil Seal
•
•
•
•
•
•
•
1. Inspect timing gear cover for absence of damage.
2. Inspect Bearing 4 seating bore in timing gear cover.
3. Turn set screw of Bearing 4 until the tip of the screw projects approx.
1 mm into the bearing seating bore in timing gear cover.
4. Heat timing gear cover to approx. 160 deg C (320 deg F) and install
Bearing 4 using special tool P 27a.
5. Tighten the bearing set screw; make sure that the screw is not too
long, such as to exert pressure upon the bearing.
6. Insert oil deflector.
7. Install oil seal using P 73 installer.
Note:
When installing Bearing 4, proceed quickly since the bearing insert will begin to
expand immediately upon contact with the hot timing gear cover and may,
possibly. bind in the process.
165
1.12.16 Timing Gear Cover R/R
Removal
•
•
•
•
•
•
•
•
•
•
1. Remove generator (5 En).
4. Remove fuel pump (13 Fu).
5. Remove crankshaft pulley (47 En). (See Note, below).
6. Remove crankshaft pulley shield.
7. Remove oil pump (21 En).
8. Remove retaining nuts from timing gear cover.
10. Remove counter-pressure oil line and rubber plugs.
Note:
To prevent damaging the oil seal in timing gear cover, remove Woodruff key
from crankshaft before wi thdra wing the cover.
Installation
166
1.12.17 Timing Gear Cover O-Rings
•
1. Use new gaskets. It should be noted that the three o-rings provided
for sealing the oil galleries between the timing gear cover and cranckase
- (See two a-rings to the left of the timing gear) are not omitted nor that
they fall out when the timing gear cover is positioned on the crankcase.
167
1.12.18 Rubber Plugs on Timing Gear
Cover
•
•
•
•
•
2. Ensure that the dowel pins are firmly seated.
3. Place one rubber plug on each end of the counter pressure oil line and
install in the timing gear cover so that the open end of the upper plug
faces the crankcase while the open end of the lower plug is inside the
timing gear cover (see Fig. 154).
4. Inspect oil seal at crankshaft pulley and replace if worn or damaged.
5. Use new gasket under generator carrier.
6. Torque retaining nuts of timing gear cover to 2 mkp (14. 5 lbs/ft).
168
1.12.19 Flywheel R/R
Special Tools:
P 44 Hex socket (36 mm)
The flywheel is attached to the crankshaft by way of a gland nut; eight dowel
pins transmit the torque forces. A soft iron gasket is installed between the
flywheel and the crankshaft. Oil sealing is accomplished by an oil seal installed
in the crankcase at Bearing 1; the seal rides on the flywheel hub. The gland
nut contains a - pilot bushing which supports one end of the transmission input
shaft.
1. Flywheel
2. Oil seal
3. Spacer
4. G land nut
5. Gasket
6. Spring washer
7. Crankcase
8. Bearing 1
9. Crankshaft
10.
Pilot bushing
11.
Oil gallery
12.
Dowel pin
13.
Soft iron gasket
169
Removal
1.
2.
3.
4.
Remove clutch pressure plate.
Withdraw clutch plate,
Remove gland nut using P 44 hex socket,
Withdraw flywheel.
Installation
following points:
170
1.12.20 Flywheel Installation
1. Inspect flywheel starter ring for serviceable condition of gear teeth;
slightly pounded teeth may be dressed with a file.
2. Check dowel pin seats in flywheel; if the seats appear peened, install a
new flywheel.
3. Check dowel pins in the crankshaft, replace if necessary.
4. Use new soft iron gasket,
5. Check and adjust crankshaft end play.
6. Check pilot bushing in gland nut for wear.
7. If the pilot bushing requires replacement, install new needle bearing with
gland nut.
8. Torque gland nut to 45-50 mkp (326-362 lbs/ft).
9. Check flywheel for runout. Maximum lateral runout is 0.3 mm (0.012 in),
measured in the middle of the clutch plate contact area. Maximum
vertical runout is 0,1 mm (0.004 in). Note specifications in the table of
tolerances.
171
1.12.21 Dowel Pin Position
Crankshaft and flywheel are balanced as a unit and always marked with a
number. It should be noted at time of installation that both identifying
numbers are same. Replacement flywheels or crankshafts are balanced to 0 so
that they are individually relaceable,
To ensure proper installation of the flywheel in relation to the crankshaft, two
dowel pins have been positioned closer together; this point is identified on the
crankshaft and flywheel by the number 1 stamped into both parts.
172
1.12.22 Reconditioning Flywheel
If necessary recondition the flywheel gradually on a lathe (according to table
below). Please pay attention to the fact that the bearing surface of the clutch
must be reconditioned by the same proportion as the thrust surface of the
flywheel.
Measuring
point
Original measure
(mm)
Grade
1
Grade
2
Grade
3
Tolerance
A
12.3
11.8
11.5
11.2
+/- 0.1
B
22.5
-
-
-
+/- 0.2
C
39.5
38.8
38.4
38.0
+/- 0.2
D
13.25
12.95
12.75
12.55
+/- 0.1
E
3.15
3.1
-
-
+/- 0.05
r
0.5
0.5
-
-
- 0.2
b
1 deg 30'
-
-
-
-
173
Crankshaft Pulley R/R
1.12.23 Crankshaft Pulley Diagram
1.
2.
3.
4.
5.
6.
7.
8.
Oil deflector
Bearing 4
Oil seal
V-belt
Spring washer
Retaining bolt
Woodruff key
Crankshaft pulley
Removal
1.
2.
3.
4.
Remove V-belt.
Remove engine rear shield.
Remove crankshaft pulley retaining bolt.
Withdraw crankshaft pulley.
174
Installation
following points:
1. Inspect crankshaft pulley, prior to installation, for good condition of its
seat and belt running surfaces.
2. Check for possible pulley runout.
3. Check oil sealing surface of pulley.
4. Check oil seal for absence of damage or wear, replace if necessary.
1.12.24 Flywheel Oil Seal R/R
Special Tools
VW 204b Crankshaft oil seal installer
Removal
1. Remove flywheel. Inspect oil sealing surface on flywheel hub.
2. Remove old oil seal.
3. Clean the oil seal seat and apply a thin coat of gasket compound, If
necessary, remove sharp edges from outer surface perimeter, making
sure to remove any remaining filings.
Installation
1. Install new oil seal using VW 204b oil seal installer; to install, screw
installer into crankshaft end and tighten guide piece which carries the oil
seal. The oil seal must rest at the bottom of its seat and must not be
slanted in the installation process.
2. Remove installer.
3. Use new soft iron gasket.
4. Instal flywheel; lightly oil the oil sealing surface (hub).
175
1.12.25Camshaft Remove / Install
Removal
1. Disassemble crankcase (41 En).
2. Withdraw camshaft.
Installation
Camshaft
•
•
1. Check for firm attachment of camshaft gear to camshaft.
2. Check camshaft for wear at bearing journals and camshaft lobes, i.e.,
rippled wear in lift ramps or slanted wear, in relation to camshaft axis, or
cam lobe races, End play specifications are shown in the table of
tolerances.
176
1.12.26 Timing Gear Position
•
•
•
3. Check camshaft for whip.
4. Check camshaft gear for good condition and proper tooth contact.
5. When installed, the camshaft gear tooth marked "0" lies between two
crankshaft gear teeth bearing a punch mark each.
177
1.12.27 Camshaft Gear Marking
•
•
•
•
6. Check gear backlash over the entire circumference of the camshaft
gear. Correct backlash, in assembled crankcase, between the camshaft
gear and crankshaft gear is 0,015 - 0,04 mm (0.0006 - 0.0016 in). To
measure, move gears back and forth while taking readings with a dial
gauge and measuring the entire circumference of the camshaft gear,
To facilitate proper backlash adjustment, camshafts are furnished with
camshaft gears in five sizes.
The camshaft gears are marked on the camshaft side with electrically
inscribed or mechanically stamped identifica don num bers such as 0,
+1, +2, -1, and -2, The numbers show, in hundreds of one millimeter,
by how much the pitch circle radius differs from standard size (0); it
identifies a standard gear 0, oversize of +1 or +2 (+ 1/100 or +2/100
mm), or undersize -gears.
Note:
Do not confuse the number "0" with the timing mark "o" on the other
side of the gear. The crankshaft gear is supplied in one size only and no
identifica tion is necessary .
7. Lubricate camshaft with graphite oil and install.
8. Do not fail to install camshaft end plug.
9. When assembling a new crankcase, check camshaft for snug but easy
rotation; if necessary check camshaft bearings with machinist's blue and
smoothen bearing seats in crankcase with a scraper.
Note:
When installing a new camshaft gear ensure that the timing mark on the
camshaft gear, its nearest mounting bolt bore, and the oil pump drive
slot on the camshaft end align in an almost straight line.
Before drilling the 5,8 mm ( 0.228 in) dowel pin holes, and tapering
these from the camshaft side, check the gear for runout, The three dowel
pins must be firmly seated in the camshaft gear and additionally secured
by three punch strikes each. If necessary, install larger dowel pins which
may be locally manufactured from high-grade steel. Torque retaining
bolts to 2,5 mkp (18 lbs/ft).
178
Crankshaft with Connecting Rods
R/R
Removal
1.
2.
3.
4.
Disassemble crankcase (41 En).
Withdraw camshaft.
Remove crankshaft with connecting rods.
Mark insert of Bearing 2 and 3.
1.12.28 Install Crankshaft
1. Lightly bevel bearing seat edges at the crankcase joint to prevent
gouging as a result of bearing preload upon reassembly of crankcase,
2. Check dowel pin in Bearing 1 for firm seating.
3. Oil passages in crankshaft journals and bearings must not have sharp
edges in evidence.
4. Install in crankcase insert halves of Bearing 2 and 3.
5. Place insert of Bearing 1 on crankshaft journal so that the off-centered
dowel pin bore is closest to the flywheel side.
6. Insert crankshaft.
7. Note timing marks when installing camshaft.
179
1.12.29 Connecting Rods R/R
Special Tools
VW 310a Crankshaft bench mount
Removal
1. Remove crankshaft and place into VW 310a bench mount (50 En).
2. Remove connecting rod retaining nuts, remove connecting rods and
caps.
180
1.12.30 Torque Connecting Rods
Installation
following points:
•
•
•
•
•
1. Check connecting rod weight: Maximum permissible weight difference
between connecting rods of one engine is 6 g ( 0.211 oz.).
2. Check piston pin bushing. The piston pin should enter a new bushing
under light finger pressure.
3. Check connecting rod alignment and correct if necessary.
4. Upon thorough cleaning of all parts install connecting rod inserts and
assemble connecting rods. The identification number stamped into the
side of the connecting rod and its bearing cap should be on the same
side when assembled.
5. Torque connecting rod retaining nuts to 4.5 mkp (32.5 lbs/ft).
181
1.12.31 Tap to Rods Relieve Stress
•
•
6. Visually check if connecting rod and its bearing cap have actually
joined, that is, if no obstruction is in the joint.
7. Minor stresses which may result from tightening the connecting rod
retaining nuts can be relieved through light hammer blows. The
connecting rods, oiled prior to installation, should tip freely under their
own weight. Under no circumstances may bearings be dressed or
reworked to fit.
182
1.12.32 Check Clearance
•
8. Check lateral clearance between connecting rods and crankshaft
(0.15-0.20 mm) (0.006 to 0.008 in).
183
1.12.33 Installing Connecting Rod
Bushings
(Connecting rods removed from engine)
If clearance between piston pin and bushing is excessive, install new bushings
in the connecting rods by noting the following points:
1. Install new bushings on a press using a round block.
2. Bring bushing bore to correct size by means of precision drilling,
3. It is in no case permissible to rebore worn bushingS and fit these with
oversize piston pins. State weight when ordering connecting rods,
Note:
If at all possible, connecting rod bushings should be brought to correct bore
size only by means of precision drilling.
Only in cases of emergency, when precision drilling equipment is not at hand,
or if economic reasons prevent the removal of crankshaft from the engine, is it
permissable to ream the connecting rod bushings, and in such. cases only with
a well guided reamer and with the greatest of care.
1.12.34 Measuring and Realigning
Connecting Rods
Special Tools:
P 14b Connecting rod measuring fixture
Measuring
1. Remove crankshaft and take off connecting rods, Mark connecting rods
and caps to ensure reassembly in original locations and posi tions.
2. Remove bearing inserts.
3. Install connecting rod in P 14b measuring fixture.
4. Insert measuring pin into connecting rod and check for twists or bends.
Aligning
184
1.12.35 Checking for Twisted
Connecting Rods
Connecting rods may be realigned in the measuring fixture with the use of a
MATRA aligning tool, or with other commercial aligning tools.
185
1.13 CRANKSHAFT
Disassembling and Reassembling
Crankshaft
Special Tools:
•
•
•
•
•
VW 161a Lock ring pliers, for removing and installing gear lock ring on
crankshaft.
VW 202 Puller with
o VW 202a Puller jaws
o VW 202f Block -- for removing gears from crankshaft
VW 310a Crankshaft bench mount
VW 427 Guide tube, for installing camshaft drive gear, spacer. and
distributor drive gear on crankshaft.
VW 428 Tapered guide tube, for installing gear lock ring on crankshaft
Specifications for Plain Bearing Crankshaft
Stroke
Connecting rod journal diameter
Main bearing journal diameter
mm
mm
mm
74 (2.913 in)
53 (2.0866 in)
Bearing 1: 50 mm (1.9685 in)
Bearing 2: 55 mm (2.1654 in)
Bearing 3: 55 mm (2.1654 in)
Bearing 4: 40 mm (1.5748 in)
186
1.13.1 Crankshaft Disassembly
1.
2.
3.
4.
Install crankshaft in VW 310a bench mount (mount has 8 seating holes).
Remove connecting rods (51 En).
Using VW 161a lock ring pliers, remove gear lock ring from crankshaft.
Remove distributor drive gear, spacer, and camshaft drive gear from
crankshaft using VW 202 puller with VW 202a puller jaws and VW 202f
block, Minor scoring in the seating surface should be removed with care
although the dressing must not impair the press fit of the gears.
187
1.13.2 Crankshaft Reassembly
following points:
1. Check crankshaft for whip, cracks (acoustical sound test), or wear,
Replace crankshaft if necessary, The crankshaft may be reground.
2.
3.
4.
5.
6.
7.
8.
The crankshaft can only be reground at the factory.
To simplify reassembly, mark insert of Bearing 1 at the crankcase joint
(this aids in locating the dowel pin seat).
Insert Woodruff key for camshaft and distributor drive gears.
Inspect camshaft drive gear for wear and tooth contact, heat to 80 deg C
(176 deg F), and press onto crankshaft, with chamfered side facing
flywheel, using VW 427 guide tube.
Check distributor drive gear for wear, replace if necessary. Heat gear to
80 deg F (176 deg F) and press onto crankshaft using VW 427 guide
tube.
Install gear lock ring on crankshaft, use VW 428 tapered guide tube to
prevent damaging the bearing journal. Check gears for firm seating when
cool.
Clear oil galleries with compressed air, flush with oil.
Install connecting rods.
188
Checking and Adjusting Crankshaft
End Play
Special Tools
P 17 Dial gauge holder, for mea suring end play in assembled engine.
Checking End Play
End play should be 0,14 - 0,17 mm ( 0.0055 to 0.0067 in), wear limit 0,22
mm ( 0.0087 in). End play should be adjusted before installing the crankshaft.
The use of more than one soft iron gaskets is not permissible.
1.13.3 Crankshaft End Play
1. Properly position Bearing 1 on Journal 1
2. Install spacer of calculated thickness. The spacers are available in
thicknesses from 0,8 to 1.05 mm (0.0315 to 00413 in) and are marked
alphabetically from A through F.
189
1.13.4 Measure End Play
•
•
Attach flywheel to crankshaft and torque gland nut to 45-50 mkp (326362 lbs/ft).
Measure end play with feeler gauge.
End play is measured at the crankshaft pulley when the engine is installed in
vehicle, and at the flywheel when the engine is removed. In both cases use a
dial gauge mounted in P 17 holder. When measuring end play at the crankshaft
pulley, attach gauge holder to a stud in the timing gear cover; when
measuring at the flywheel, attach the holder to the engine mounting flange by
means of a bolt.
190
1.13.5 Calculating End Play
1. Place gauge base on the end of the crankshaft and measure distance
from crankshaft end to the thrust flank of Bearing 1 (crankshaft pushed
to flywheel).
2. Place gauge base on the flywheel hub and measure depth of seat
(flywheel hub takes up the thrust, hub seat rests on crankshaft end).
From the difference between both readings, and considering the thickness of
the soft iron gasket, the thickness of the required spacer may be determined.
The soft iron gasket thickness is 0.10 - O. 14 mm (0.004 - 0.006 in) The use
of more than one soft iron gaskets is not permissible.
191
Example:
(1 mm = 0.03937 in.)
Crankshaft-end to Bearing 1 thrust flank
Crankshaft seat depth in flywheel hub
4.015 mm
- 3.025 mm
O.990 mm
Soft iron gasket thickness
+ 0.100 mm
1.090 mm
Required end play
- 0.140 mm
Spacer Thickness =
0.950 mm
192
1.13.6 Reconditioning Crankshaft
Crankshafts can only be reground at the factory and/or obtained through the
exchange service, as these crankshafts demand a special treatment of
material. Appropriate undersize bearings are available within the spare part
program; it must be determined however, if the main bearing bores in the
crankcase are standard or oversize.
Main Bearing and Crankshaft Journal Dimensions
(1 mm = .03937 in)
MAIN BEARINGS
Nomenclature
Crankshaft
Journal
Bearing Insert
Crankcase Bore
Crankshaft
Journal
Bearing Insert
Version
Standard
Bearing 2
and 3
Diameter
Inside
standard
Wall
thickness
Outside
standard
Outside
diameter
Standard
Standard
Diameter
Diameter
Inside
standard
Wall
thickness
Outside
oversize
Outside
diameter
Bearing 1
54.99054.971
49.99149.975
2.615 2.603
5.0965.108
-
60.24 +/0.005
60.29 +
0.02
60.24 +/0.005
54.99054.971
49.99149.975
2.7402.728
5.221 5.233
-
60.54 +
O.02
Crankcase
Bore
Oversize
Diameter
60.49 +/O.005
60.49 +/0.005
Crankshaft
Journal
1st
undersize
Diameter
54.74054.721
49.74149.725
193
Bearing Insert
Inside
undersize
Wall
thickness
Outside
standard
Outside
diameter
2.7402.728
-
5.221 5.233
60.29 +
0.02
Crankcase
Bore
Standard
Diameter
60.24 +/0.005
60.24 +/O.005
Crankshaft
Journal
1st
undersize
Diameter
54.74054.721
49.74149.725
Inside
undersize
Wall
thickness
2.8652.853
5.3465.358
Outside
oversize
Outside
diameter
Bearing Insert
-
60.54 +/O.02
Crankcase
Bore
Oversize
Diameter
60.49 +/0.005
60.49 +/0.005
Cankshaft
Journal
2nd
undersize
Diameter
54.49054.471
49.49149.475
Bearing
Insert
Inside
undersize
Wall
thickness
2.8652.853
5.3465.358
Outside
standard
Outside
diameter
-
60.29 +
0.02
Crankcase
Bore
Standard
Diameter
60.24 +/0.005
60.24 +/0.005
Crankshaft
journal
2nd
undersize
Diameter
54.49054.471
49.49149.475
2.990 2.978
5.471 5.483
Bearing Insert
Inside
undersize
Wall
thickness
Outside
Outside
194
-
60.54 +
oversize
diameter
0.02
Crankcase
Bore
Oversize
Diameter
60.49 +/0.005
60.49 +/0.005
Crankshaft
Journal
3rd
undersize
Diameter
54.24054.221
49.24149.225
2.9902.978
5.4715.483
Bearing Insert
Crankcase
Bore
Crankshaft
Journal
Bearing Insert
Crnakcase
Bore
Inside
undersize
Wall
thickness
Outside
standard
Outside
diameter
Standard
3rd
undersize
60.29 +
0.02
Diameter
60.24 +/0.005
60.24 +/0.005
Diameter
54.24054.221
49.24149.225
Inside
undersize
Wall
thickness
Outside
oversize
Outside
diameter
Oversize
-
Diameter
195
3.1153.103
-
60.49 +/0.005
-
60.54 +
0.02
60.49 +/0.005
1.13.7 Measuring Bearing Inserts
Measuring point for establishing thickness of bearing inserts.
196
1.14 THE CLUTCH
Description of the Clutch
General
A dry single plate clutch is incorporated in the flywheel between engine and
transmission. The spring cushioned clutch disc has friction linings on both
sides. It rides in the splined input shaft and has axial freedom of movement.
The diaphragm spring, together with the clutch assembly, is centrally mounted
in the flywheel. In engaged condition, the clutch disc is held against the
flywheel by the pressure plate upon which the diaphragm spring acts, thus
providing a mechanical lock between the engine and transmission.
1.14.1 Diagram of the Clutch
The clutch control fork, mounted in the transmission housing, carries the
throwout bearing. The throwout bearing is permanently lubricated and requires
no maintenance.
Clutch actuation at disengagement is by way of the clutch pedal, clutch cable,
control fork, and throwout bearing. The throwout bearing exerts pressure upon
the segments of the diaphragm spring, displacing it axially. The resulting
deflection of the diaphragm spring relieves pressure from the pressure plate
and, thus, from the clutch disc, resulting in disengagement of engine from the
transmission.
Clutch maintenance is limited to adjustment of the clutch pedal clearance of
20-25 mm (3/4 to 1 in.) in the course of normal clutch lining wear, and also to
the adjustment of the clutch pedal travel limiter.
197
1.14.2 Remove Clutch
1. Remove engine and detach from transmission.
2. Evenly loosen clutch retaining bolts, slackening each by one or two turns
at a time and switching in a cross sequence until the spring pressure is
relieved, to a void distortion of spring housing.
3. Withdraw clutch assembly.
4. Withdraw clutch disc,
198
1.14.3 Clutch Installation
1. Clean clutch contact surface in flywheel and check for wear, If necessary
reface surface and polish with fine polishing cloth. Replace flywheel if
excessively worn.
2. Check clutch disc for lining wear, lateral run out, and evenly working
undulated spacers between both lining discs. Devote special attention to
riveted joints securing flange to disc, If necessary, replace complete
clutch disc assembly.
3. Check torsion damper for firm seating and inspect springs for cracks. If
in defective condition, replace clutch disc assembly.
4. Inspect clutch assembly.
5. Check throwout bearing for wear and smooth rotation, replace if
necessary.
6. Check control fork seat in transmission housing for wear and good
seating, repair if defective.
7. Fill bushing in gland nut at flywheel with approx, 2 cc (.12 cu, in,)
graphite grease or MoS2 compound,
8. Install clutch disc with the aid of an arbor or a shortened transmission
input shaft.
9. Push clutch assembly onto aligning dowels in flywheel. If the flywheel is
not provided with dowel pins, align clutch assembly with the help of P
219 locating arbor.
10.
Evenly tighten clutch retaining bolts, turning each by one or two
turns at a time in a cross sequence to avoid distortion of spring housing,
Use only 10 K hex bolts with lock washers, Torque bolts to 3,5 mkp (25,3
lbs/ft).
11.
With transmission attached to the engine pull clutch control lever in
direction of arrow, The distance between the lever and transmission
housing should still be not less than 20 mm (4/5 in,),
199
Inspecting Clutch Disk
1.14.4 Measure Clutch Thickness
1. The clutch linings are riveted to undulated spring segments which curve
from side to side and provide a cushioning effect in the clutch disc. It is
essential for proper functioning of the clutch that the cushioning action of
individual segments is equal in all sections of the clutch disc.
2. The clutch disc should slide freely on the splined input shaft but it must not
show evidence of radial play,
3. Inspect clutch linings. If the linings are oiled, scorched, torn, or worn
considerably. install a new clutch disc.
Visible formation of cracks in the lining surface between the rivets can be
disregarded.
Clutch disc with riveted linings:
Compressed thickness = 9,2 +/- 0,2 mm (0.362 +/- 0.008 in)
Wear limit = 8 - 7. 8 mm (0.315 - 0.307 in)
Measurements are taken between both friction surfaces of the clutch disc.
Thickness A, decompressed = 10,1 - 0.4 mm (0.398 - 0.016 in)
200
1.14.5 Check Clutch Disk for Runout
4. Check clutch disc for run out at linings: Permissible runout is 0.6 mm (0.024
in).
201
1.14.6 Inspecting Clutch Assembly
Inspection
The Fichtel-Sachs MX 200 K clutch has been designed without provision for
repair or overhaul. The clutch inspection is, therefore, limited to a thorough
visual examination of the component parts.
1.14.7 Check Pressure Plate
1. Clean the clutch.
2. Check diaphragm spring segments for wear in the throwout bearing contact
area. Groove formation up to a depth of O. 3mm (0.012 in) may be
disregarded.
3. Check pressure plate contact surface for cracks, scorching, or wear.
Pressure plates warped inward up to 0,3 mm (0.012 in) (see illustration) are
still serviceable.
202
1.14.8 Check Clutch Attachment
Points
4. Check attachment points of diaphragm spring and spring housing for cracks.
Check rivets for firm seating. Clutch assemblies with damaged or loose rivet
connections must be replaced.
203
1.14.9 Check Wear of Rivet Heads
5. The diaphragm spring is riveted to the spring housing with two wire ring
spacers in between.
Clutch assemblies. showing visible wear at the rivet heads or at the wire ring
spacers should be replaced.
6. Lightly coat the diaphragm spring seat at the wire ring seating area with
MoS2 paste prior to installation.
204
1.14.10 Adjusting Clutch
General
Both ends of the clutch cable have threads and may be adjusted at either the
clutch control lever in transmission housing or at the clutch pedal. The clutch is
correctly adjusted when clutch pedal free travel is 20 - 25 mm (3/4 to 1 in,).
The adjustment should be made with care since insufficient clearance will
result in clutch slippage followed by burnt linings.
Adjusting Clutch Free-Play at Control Lever
1.14.11 Adjust Clutch Free-Play at
Control Lever
1. With car on stands, loosen lock nut at clutch lever clevis.
2. Adjust clutch free travel (20-25 mm or 3/4 to 1 in.) by turning the
adjusting nut.
3. Tighten lock nut when adjustment is made.
205
1.14.12 Adjust Free-Play at Clutch
Pedal
1. Remove rubber mat located in front of passenger seat.
2. Raise rubber cover from center tunnel and fold back.
3. Loosen lock nut in threaded part of cable at clevis. Pull retaining spring
off clevis pin and withdraw pin,
4. Adjust by turning the clevis. The clevis may be turned only until it is
flush with the cable bolt.
5. Tighten lock nut when adjustment is completed check clevis pin retaining
spring for proper seating. Thoroughly lubricate threaded part of cable
end.
206
1.14.13 Adjusting Clutch Travel
Limits
Note:
The diaphragm spring clutch requires an exactly limited clutch pedal travel.
Whenever work has been performed on the clutch, check and correctly adjust
the clutch pedal travel.
Checking
1. Bring transmission to operating temperature.
2. Depress clutch pedal to stop. At this point the reverse gear should
silently engage, allowing a quick moment of pause between pedal
depression and gearshift movement.
207
1.14.14 Adjusting Clutch Pedal
Travel
1.
2.
3.
4.
5.
Remove rubber mat.
Loosen both limiter retaining bolts with a 3 mm Allen-head wrench.
Slide the limiter up or down, as required.
Tighten limiter retaining bolts.
Check clutch pedal travel as outlined above.
208
1.15 TOLERANCES AND WEAR LIMITS
1.15.1 Cylinder Seat Depth in
Cylinder Head
Measuring point
1. Cylinder seat depth in
cylinder head
Tolerance (new)
Wear Limit
9.500-9.600 mm
(0.374-0.378 in)
10.000 mmm
(0.3937 in)
209
1.15.2 Cylinder Bore Ovality
Measuring point
Tolerance
(new)
2. Cylinder bore ovality, B minus
A
n/a
Wear Limit
0.020 mm (0.0008
in)
1.15.3 Piston Ring Gap
Measuring point
Tolerance (new)
6. Piston ring gap
0.15-0.30 mm (0.0059-0.0118 in)
210
Wear Limit
0.95 (0.0374)
1.15.4 Piston Pin to Connecting Rod
Clearance
Measuring point
9. Piston pin to connecting
rod clearance
Tolerance (new)
0.012-0.028 mm
(0.0005-0.0011 in)
Wear Limit
0.042 mm
(0.0017 in)
1.15.5 Crank Pin to Connecting Rod
Clearance
Measuring point
10. Crank pin to connecting
rod clearance
Tolerance (new)
0.040-0.092 mm
(0.0016-0.0036 in)
211
Wear Limit
0.130 mm
(0.0051 in)
1.15.6 Crankshaft to Main Bearing
Clearance
Measuring point
11. Crankshaft to main
bearing clearance (bearings
installed)
Tolerance (new)
Wear Limit
a. Bearing 1. 0.028-0.078
mm (0.0011-0.0031 in)
0.170 mm
(0.0067 in)
b. Bearing 2 and 3. 0.0460.100 mm (0.0018-0.0039
in)
0.170 mm
(0.0067 in)
c. Bearing 4. 0.040-0.104
mm (0.0016-0.0041 in)
0.170 mm
(0.0067 in)
212
1.15.7 Crankshaft Runout
Measuring point
Tolerance (new)
12. Crankshaft runout at Bearing 2
and 4 (Bearing 1 and 3 on V -blocks)
max. 0.020 mm
(0.0008 in)
213
Wear Limit
0.030 mm
(0.0012 in)
1.15.8 Crankshaft to Crankshaft
Thrust Bearing
Measuring point
13. Crankshaft to crankshaft
thrust bearing
Tolerance (new)
0.13-0.18 mm (0.00510.0071 in)
214
Wear Limit
0.3 mm
(0.0118 in)
1.15.9 Diagram of the Clutch
The clutch control fork, mounted in the transmission housing, carries the
throwout bearing. The throwout bearing is permanently lubricated and requires
no maintenance.
Clutch actuation at disengagement is by way of the clutch pedal, clutch cable,
control fork, and throwout bearing. The throwout bearing exerts pressure upon
the segments of the diaphragm spring, displacing it axially. The resulting
deflection of the diaphragm spring relieves pressure from the pressure plate
and, thus, from the clutch disc, resulting in disengagement of engine from the
transmission.
Clutch maintenance is limited to adjustment of the clutch pedal clearance of
20-25 mm (3/4 to 1 in.) in the course of normal clutch lining wear, and also to
the adjustment of the clutch pedal travel limiter.
215
1.15.10 Crankshaft Pulley Runout
Measuring point
17. Crankshaft pulley
runout
Tolerance (new)
vertical. A max. 0.250 mm (0.0098
in)
B max. 0.250 mm (0.0098 in)
216
Wear
Limit
1.15.11 Camshaft Bearing Clearance
Measuring point
19a. Camshaft bearing
clearance
Tolerance (new)
0.020-0.054 mm (0.00080.0021 in)
217
Wear Limit
0.120 mm
(0.0047 in)
1.15.12 Camshaft End Play at Thrust
End
Measuring point
19b. Camshaft end play at
thrust end
Tolerance (new)
0.040-0.080 mm (0.00160.0031 in)
218
Wear Limit
0.100 mm
(0.0039 in)
1.15.13 Camshaft Center Bearing
Runout
Measuring point
Tolerance
(new)
19c. Camshaft center bearing runout
(camshaft mounted on centers)
0.020 mm
(0.0008 in)
Wear Limit
0.025 mm
(0.0010 in)
1.15.14 Lateral Runout
Measuring point
Tolerance (new)
20. Timing gear run out (gear bolted and
pinned to camshaft): Lateral runout
219
max. 0.100 mm
(0.0039 in)
Wear
Limit
1.15.15 Vertical Runout
Measuring point
20c. Timing gear runout: Vertical
runout
Tolerance (new)
0.025 mm (0.0010
in)
Wear Limit
0.040 mm (0.0016
in)
1.15.16 Flywheel Lateral Runout
Measuring point
Tolerance (new)
21a. Flywheel: Lateral runout measured
at starter ring (A):
220
max. 0.300 mm
(0.0118 in)
Wear
Limit
Flywheel Lateral Runout
Measuring point
Tolerance (new)
21b. Flywheel: Lateral runout, measured in
clutch plate recess (B):
Wear
Limit
max 0.040 mm
(0.0016 in)
1.15.17 Flywheel Vertical Runout
Measuring point
Tolerance (new)
21c. Flywheel: Vertical runout, measured
at starter ring (C):
221
max 0.020 mm
(0.0008 in)
Wear
Limit
Flywheel Vertical Runout
Measuring point
Tolerance (new)
21d. Flywheel: Vertical runout, measured
in clutch disk recess (D):
Wear
Limit
max 0.100 mm
(0.0039 in)
1.15.18 Flywheel Diam of Oil Sealing
Surface
Measuring point
21e. Flywheel: Diameter of oil
sealing surface at hub (E):
Tolerance (new)
59.000-60.100 mm
(2.3583-2.3661 in)
222
Wear Limit
59.700 mm
(2.3403 in)
1.15.19 Flywheel Depth of Recess to
Web
Measuring point
21f. Flywheel: Depth of recess to
web (F):
Tolerance (new)
6.3-6.85 mm (0.24800.2697 in)
223
Wear
Limit
1.15.20 Flywheel Web Thickness
Measuring point
21g. Flywheel: Web
thickness (G):
Tolerance (new)
6.3-6.85 mm (0.2480 0.2697 in)
Wear Limit
min 4.800 mm
(0.1890 in)
1.15.21 Flywheel Width of Oil
Sealing Area
Measuring point
21h. Flywheel: Width of oil
sealing area (H):
Tolerance (new)
9.250 - 10.250 mm (0.3642 0.4035 in)
224
Wear
Limit
1.15.22 Valve Guide Clearances
Measuring point
Tolerance (new)
Wear Limit
23a. Valve guide to valve stem
clearance. a) Valve guild inside
diameter
10.025-10.040 mm
(0.3947-0.3953 in)
10.070 mm
(0.3965 in)
23b. Valve guide to valve stem
clearance. b) Intake valve clearance
in bore
0.035-0.060 mm
(0.0014-0.0024 in)
0.120 mm
(0.0047 in)
23c. Valve guide to valve stem
clearance. c) Exhaust valve
clearance in bore
0.055-0.080 mm
(0.0022-0.0031 in)
0.120 mm
(0.0047 in)
225
1.15.23 Valve Seat
Measuring point
Tolerance (new)
24a. Valve Seat: Intake seat width
a)
1.25 +/- 0.15 (0.0492 +/0.0059 in)
24b. Valve Seat: Exhaust seat width
a)
1.55 +/- 0.15 (0.0610 +/0.0059 in)
24c. Valve Seat: Lateral Runout of
valve head to seat
0.010 (0.0004 in)
226
Wear
Limit
1.15.24 Valve Springs
Measuring point
Tolerance (new)
25a. Valve Spring length decompressed
47 mm (1.85 in)
25b. Valve Spring length installed, intake
41 mm (1.61 in)
25c. Valve Spring length installed,
exhaust
40.5 mm (1.59 in)
25d. Valve Spring pressure when
compressed to 41 mm length
36 +/- 1.5 kp (79
+/- 3.3 lbs)
25e. Valve Spring pressure when
compressed to 30.1 mm length
97 +/- 2.5 kp (213
+/- 5.5 lbs)
227
Wear
Limit
1.15.25 Valve Spring Lengths
Measuring point
Tolerance (new)
25d. Valve Spring pressure when
compressed to 41 mm length
36 +/- 1.5 kp (79
+/- 3.3 lbs)
25e. Valve Spring pressure when
compressed to 30.1 mm length
97 +/- 2.5 kp (213
+/- 5.5 lbs)
228
Wear
Limit
1.15.26 Valve Lifter Dimensions
Measuring
point
28. Valve
Lifter
Tolerance (new)
Wear Limit
bore in crankcase (diam): 12.000-12.018
(0.475-0.4731)
12.060
(0.4748)
diameter: 11.966-11.984 (.4711-0.4718)
11.945
(0.4703)
to crankcase bore clearance: 0.016-0.052
(0.0006-0.0020)
0.100
(0.0039)
229
1.15 27 Oil Pump
Measuring
point
30.Oil Pump
Tolerance (new)
Wear Limit
Pump gears extend beyond housing (no
gasket):
0.06-0.125 (0.0024-0.0049)
Thickness of compressed gasket (A):
0.16 (0.0063)
Gear end play, with gasket and cover
installed (B):
0.035-0.10 (0.0014-0.0039)
Gear backlash:
0.030-0.080 (0.0012-0.0031)
230
0.20
(0.0079)
1.15.28 Pressure Relief Spring
Measuring point
31. Spring for pressure releif valve
in crankcase and timing gear cover
Tolerance (new)
Free length:
66 mm (2.6 in)
Spring pressure when
compressed to 49 mm:
4.7 kp +/- 7% (10.4 lbs
+/- 7%)
Spring wire cross section
(diam):
1.4 (0.55)
231
Wear
Limit
1.15.29 Torque Values for Bolts and
Nuts
(1 mkp = 7.233 lbs/ft)
Fastener
mkp
lbs/ft
Crankcase bolts
2.5
18
Timing gear cover nuts
2.0
14.5
Connecting rod nuts (without safety plates)
4.5
32.5
Cap nuts for through - bolts
4.0
28.9
Cylinder head nuts
3.0
21.7
Rocker arm carrier retaining bolts
5.0
36.2
Camshaft gear retaining nuts
2.5
18
Rocker arm shaft retaining nuts
2-2.5
14.5-18
Blower impeller retaining nut
10.0
72.3
Flywheel gland nut
35-37
253-268
232
2. FUEL
2.1 FUEL SYSTEM DESCRIPTION
The Fuel System Consists of the Following Major Components:
1.
2.
3.
4.
Fuel tank
Fuel lines
Mechanical fuel pump
Two double - throat downdraft carburetors with air cleaner
The fuel tank is located under the front lid beneath the luggage compartment.
It has a capacity of 62 liters (16.4 US gal.) of which 7 liters (1. 8 US gal.) are
the reserve.
The fuel supply line leads to the fuel pump through the frame tunnel.
The fuel pump is actuated by a cam, machined into the distributor pinion shaft,
over an actuating plunger.
Each bank of two cylinders has one double-throat downdraft carburetor with ail
accelerating pump.
The air cleaners or induction silencers remove dust and dirt from the induction
air.
233
2.2 DESCRIPTION OF THE SOLEX 40
P II - 4 CARBURETOR
2.2.1 Solex 40 P II-4 Solid Shaft
Parts list
234
Spare parts for carburetor Solex 40 P II-4 with through throttle spindle
616/36/37
Part No
Description
Qty
1
616.100.975.00
Carburetor housing
1
2
616.100.976.00
Stud
2
3
616.100.912.02
Throttle Spindle
1
4
616.108.912.00
Throttle oval
2
5
616.100.917.00
Throttle butterfly fixing screw
4
6
616.100.978.00
Throttle lever for right caburetor with thrust
bloc
1
(6)
616.100.977.00
Throttle lever for left caburetor with thrust
bloc
1
7
616.100.918.00
Pump intermediate actuating lever
1
8
616.100.921.00
Cylindrical pin for intermediate lever
1
9
616.100.922.00
Return spring for intermediate lever
1
10
616.100.923.00
Slow running adjustment screw
1
11
616.100.814.00
12
616.100.815.00
Washer for throttle spindle
1
13
616.100.913.00
Throttle spindle end nut
2
14
616.100.926.00
Lock washer for hexagon nut
2
15
616.100.927.01
Volume control screw
2
16
616.100.814.00
Pressure spring for volume control screw
2
17
616.100.928.00
Screw plug
1
18
616.100.929.00
Gasket for screw plug
1
19
616.100.931.00
Choke tube 32
2
20
616.100.931.00
Fixing screw for choke tube
2
21
616.100.935.00
Hexagon nut
2
22
616.100.933.00
Pre-emulsifier
2
23
616.100.931.00
Fixing screw
2
24
616.100.932.00
Hexagon nut
2
25
616.100.932.02
Idling jet air bleed (u) 1.8
2
26
616.100.901.02
Idling jet (g) 57.5
2
Fig
No
Pressure spring for slow running adjustment
screw
235
1
27
616.100.914.01
Main jet carrier
2
28
616.100.915.00
Gasket
2
29
547.100.937.02
Main jet 120
2
29
616.100.935.00
Main jet 115 for USA
2
30
616.100.936.00
Pump jet (Gp) 50
2
31
616.100.937.00
Gasket
2
32
616.100.938.00
Jet 0.7 cal.
2
33
616.100.907.02
Emulsion tube No. 25
2
34
616.100.900.02
Air correction jet (a) 180
2
35
616.100.906.01
Float 7.4 gr
1
36
616.100.911.01
Float pivot
1
37
616.100.940.00
Arm for adjustment of fuel level
1
38
616.100.911.00
Pivot for arm
1
39
616.100.941.00
Adjusting screw
1
40
616.100.932.00
Hexagon nut
1
41
616.100.942.00
Lock plate
1
42
616.100.943.01
Ball Valve
1
43
616.100.944.00
Screen
1
44
616.100.937.00
Gasket
1
45
692.100.966.01
Pump injector 0.35
1
46
692.100.697.01
Pump injector 0.35
1
47
616.100.947.00
Fixing screw
2
48
692.100.968.00
Gasket
2
49-55
692.100.969.00
Accelerator pump compl.
1
49
616.100.950.00
Pump body
1
50
616.100.951.00
Pump diaphram
1
51
616.100.952.00
Diaphram sprint
1
52-54
692.100.970.00
Cover with pump lever
1
52
616.100.954.00
Cover
1
53
692.100.971.00
Lever
1
54
616.100.956.00
Pump lever spindle
1
55
616.100.939.00
Fixing screw
2
56
616.100.957.00
Gasket
1
236
57
616.100.958.00
Pump fixing screw
4
58-65
692.100.972.00
Pump control rod complete
1
58
692.100.973.00
Pump control rod
1
59
616.100.961.00
Spring
1
60
616.100.962.00
Washer
1
61
616.100.963.00
Split pin
1
62
616.100.964.00
Nut
1
63
616.100.925.00
Hexagon nut
1
64
616.100.965.00
Washer
2
65
616.100.966.00
Split pin
2
66
616.100.967.02
Float chamber cover
1
67
616.100.968.00
Gasket for cover
1
68
616.100.969.00
Securing screw
2
69
616.100.970.00
Pressure spring for securing screw
2
70
616.100.971.00
Needel valve 1.75 with ball
1
71
616.108.423.00
Gasket for needle valve
1
72
616.100.867.00
Hollow bolt
1
73
616.108.423.00
Gasket
2
74
616.100.972.00
Float chamber assembley screw
7
75
616.100.973.00
Spring washer for screw
7
76
692.100.974.00
Support
1
77
616.100.934.00
Float chamber assembly screw
1
78
616.100.973.00
Spring washer
1
79
999.522.003.02
Spring, between holder and throttle lever
1
237
2.2.2 Solex 40 PII-4 Split Shaft
Parts List
LATER CARS
238
Spare parts for carburetor Solex 40 P II-4 with divided throttle spindle.
Part No
Description
Qty
1
616.100.975.02
Carburetor housing for carburetor II
1
1
616.100.975.01
Carburetor housing for carburetor I
1
2
616.100.946.00
Stud
2
3
616.100.912.05
Throttle spindle
1
3a
616.100.912.06
Throttle spindle
1
4
616.100.909.03
Throttle
2
5
616.100.917.00
Fixing screw
4
6
692.100.991.07
Coupling lever for carburetor I
1
7
547.100.922.03
Throttle lever for carburetor I
1
8
692.100.991.05
Coupling lever for carburetor II
1
9
692.100.991.08
Coupling lever for carburetor I
1
10
692.100.991.06
Coupling lever for carburetor II
1
11
692.100.992.00
Taper pin
2
11a
692.100.993.01
Spring clamp
1
11b
692.100.994.00
Stud
2
12
616.100.923.00
Slow running adjustment
1
13
616.100.814.00
14
616.100.962.06
Washer
4
14a
616.100.962.02
Washer
1
14b
616.100.962.03
Washer
1
15
616.100.913.00
Hexagon nut
2
16
616.100.926.00
Lock waher
2
17
616.100.991.01
Volume control screw
2
18
616.100.991.01
Pressure spring
2
19
616.100.928.00
Screw plug
1
20
616.100.929.00
asket
1
21
616.100.930.00
Draught catcher 32
2
22
616.100.931.00
Fixing scew
2
23
616.100.932.00
Hexagon nut
2
Fig
No
Pressure ring for slow running adjustment
screw
239
1
24
616.100.933.01
Diffusor
2
25
616.133.931.00
Fixing screw
2
26
616.100.932.00
Hexagon nut
2
27
616.100.902.08
Idling jet air (u) 1.1
2
28
616.100.777.00
Idling jet (g) 55
2
28a
616.100.901.02
Idling jet (g) 57.5
2
29
616.100.914.01
Main jet carrier
2
30
616.100.915.00
Seal ring
2
31
616.100.935.05
Main jet 122.5
2
32
616.100.708.06
Pump jey (Gp) 40
2
33
616.100.937.00
Seal ring
2
34
616.100.938.00
Jet 0.7 cal
2
35
616.100.907.02
Emulsion tube No. 25
2
36
616.100.900.02
Air correction jet (a) 180
2
37
616.100.906.01
Float 7.4 gr
1
38
616.100.911.01
Float pivot
1
39
616.100.940.00
Arm
1
40
616.100.941.00
Pivot for arm
1
41
616.100.941.00
Ajdusting screw
1
42
616.100.932.00
Hexagon nut
1
43
616.100.942.00
Lock plate
1
44
616.100.943.00
Ball valve
1
45
616.100.944.00
Screen
1
46
616.100.937.00
Joint
1
47
692.100.966.02
Pump injector 0.40
1
692.100.998.00
Spatium
2
48
692.100.967.02
Pump injector 0.40
1
49
616.100.947.00
Fixing screw
2
50
692.100.968.00
Gasket
2
692.100.969.01
Acclerator pump compl. for carburetor I
1
692.100.969.02
Acclerator pump compl. for carburetor II
1
51
616.100.950.01
Pump body
1
52
616.100.951.00
Pump diaphram
1
240
53
616.100.952.01
Diaphram spring
1
616.100.767.02
Pump cover compl. for carburetor I
1
616.100.767.03
Pump cover compl. for carburetor II
1
54
616.100.954.01
Pump cover
1
55
692.100.971.00
Pump lever for carburetor I
1
55a
692.100.971.01
Pump lever for carburetor II
1
56
616.100.956.00
Pivot
1
57
616.100.939.00
Fixing screw
2
58
616.100.957.00
Gasket
1
59
616.100.958.00
Fixing screw
4
692.100.972.02
Pump-perch. compl.
1
692.100.972.03
Pump control rod, compl.
1
60
692.100.973.02
Pump control rod
1
(60)
692.100.973.03
61
616.100.961.00
Pressure spring
1
62
616.100.962.04
Washer
1
64
616.100.925.00
Nut
1
65
616.100.925.00
Hexagon nut
1
66
692.100.995.00
Blankholder
1
67
692.100.996.00
Cheese head screw
1
68
616.100.967.02
Float chamber cover
1
69
616.100.968.00
Float chamber cover gasket
1
70
616.100.969.00
Securing screw
2
71
616.100.970.02
Pressure ring for securing screw
2
72
616.100.971.00
Needle valve
1
73
616.108.423.00
Gasket
1
74
616.100.867.00
Hollow bolt
1
75
616.108.423.00
Gasket
1
76
616.100.972.00
1
77
616.100.973.00
Spring washer
1
79
692.100.974.00
Holder
1
80
616.100.934.00
1
81
616.100.973.00
Spring washer
1
Pump-perch
241
1
82
999.522.003.02
Spring
1
83
692.100.997.00
Shaft-screw
2
84
547.100.922.02
Throttle lever for carburetor II
1
85
616.100.962.05
Washer
1
242
2.2.3 Solex 40 P II-4 Diagram
The Type 912 Porsche is equipped with two SOLEX 40 P II - 4 double-throat
downdraft carburetors. The induction throats are 40 mm (1.575in) in diameter.
Since the carburetors are located very close to the combustion chambers, cold
starting enrichment devices are not needed.
1. Cover retaining screws
2. Power enrichment nozzle
3. Float needle valve
4. Fuel line connector
5. Carburetor cover
6. Cover gasket
7. A ccelerating pump nozzle
8. Carburetor body
9. Idle jet
10.
Float level adjustment
11.
Accelerating pump
12.
A ccelerating pump adjustment
13.
A ccelerating pump lever
14.
Accelerating pump rod
15.
Main jet carrier with jet
16.
Idle mixture adjustment
17.
Idle speed adjustment
18.
Throttle shaft
19.
Throttle rerum stop
20.
Throttle arm
21.
Accelerating pump jet
22.
Preatomizer
23.
Air correction jet
243
2.2.4 Solex 40 P II-4 Cross Section
The carburetor basically consists of the main body and cover, with a gasket
separating the two. The main body contains two induction barrels, each having
an independent idle and power metering system. The throttle shaft, which
passes through both barrels, controls both throttle valves and carries a throttle
return stop and throttle arm.
1. Idle metering jet
2. Idle air bleed
3. Venturi
4. Preatomizer
5. Power enrichment nozzle
6. Air correction jet
7. Emulsioning tube
8. Power enrichment jets
9. Air correction jet
10.
Emulsioning tube
11.
Power enrichment nozzle
12.
Preatomizer
13.
Venturi
14.
Idle air bleed
15.
Idle metering jet
16.
Main jet carrier
17.
18.
Throttle valve
19.
Float chamber
20.
Throttle valve
21.
22.
Main jet carrier
244
2.2.5 Solex 40 P II-4 Lateral Cross
Section
The accelerating pump located on the broad side of the carburetor is actuated
through an adjustable rod and feeds fuel to both induction throats.
1.
2.
3.
4.
5.
6.
7.
8.
9.
Preatomizer
Accelerating pump nozzle
A ccelerating pump jet
Pump diaphragm spring
Pump diaphragm
Fuel passage, float chamber to check valve
Check valve with return flow port
Pump rod spring
Pump arm
245
2.2.6 The Float Chamber
The float chamber is located between both induction throats. The fuel level in
the float chamber is regulated through the buoyancy of the float, that is, the
float tang opens or closes the float needle valve. The float level may be
adjusted by means of an externally located screw which adjusts the height of
the intermediate swivel joint. This provision makes it possible to easily adjust
the float level for the particular grade of fuel used. The fuel level may be
checked by removing the plug from the inspection port.
1.
2.
3.
4.
5.
6.
Float chamber vent
Float needle valve
Carburetor cover
Threads for fuel line connector
Inspection port plug 6 Float
Float level adjusting screw
246
2.2.7 Idle Metering
The fuel enters through the idle metering jet (g) and mixes with air entering
through the idle air bleed (u) forming an emulsion. The emulsion flows to four
small discharge ports located near the throttle valve. The amount of emulsion
dispensed through the lowest port is controlled by the idle mixture screw (W).
The emulsion dispensed into the induction throat through the idle mixture port
combines with induction air which is passing through the partly open throttle
valve and atomizes into idle mixture.
The idle mixture can be leaned out by turning the adjustment screw in, and
enriched by turning it out: both screws should be set approximately same.
The idle speed adjustment controls the engine idle rpm, i. e.. turning the screw
clockwise increases the rpm, and turning it counterclockwise decreases rpm.
The idle system employed in this carburetor is an independent system since it
draws the fuel from a point before the main jet carrier (Y). As a result,
negative pressures prevailing in the induction throat have a continuous effect
on the idle metering system and a certain amount of the idle mixture is fed
into the induction throats at normal power settings as well.
247
2.2.8 Intermediate Metering
The three discharge ports located above the idle mixture discharge port
provide progressive metering at intermediate throttle openings between idling
and power. The lowest port, located at the throttle valve level, feeds idle
mixture when the throttle is set for idling, while the two upper ports begin to
feed the mixture as the throttle begins to open. This metering provision
ensures smooth transition from idle speeds to power settings.
248
2.2.9 Partial Load
The fuel flows through the main jet carrier (Y) and the main jet (Gg) into a well
which contains the emulsion tube (s) and, directly above it, the air correction
jet (a). Vacuum in the induction throat draws the fuel into the preatomizer (X)
where it mixes with air and continues to the venturi (K) where it is fully
atomized into the combustion mixture. As the vacuum in the induction throat
increases, the fuel level in the emulsion tube well decreases and air enters
through the air correction jet, mixing with the fuel through orifices in the
emulsion tube and effecting a derichment of the fuel air mixture.
249
2.2.10 Full Power with Enrichment
As long as the engine is operating in the mid-rpm range under partial or full
throttle load, only the main metering system supplies the fuel. However, as the
air velocity in. the induction throat increases with increasing rpm, the vacuum
effect in the throat becomes so intense that it begins to draw supplemental
fuel from the power enrichment nozzle (q1); the power enrichment system
consists of the discharge nozzle ([1) and the metering jet (q2) and draws fuel
directly from the float chamber. The enrichment system comes into action
when the engine is running under full throttle at high rpm.
The main metering system together with its supplemental enrichment system
ensures a well balanced and metered fuel! air mixture required for combustion,
realizing the desired fuel economy and, yet, maximum power output on
demand.
250
2.2.11 Acceleration
A mechanically actuated diaphragm-type accelerating pump is employed. The
pump receives fuel directly from the float chamber. When the pump is at rest,.
the diaphragm (M) is kept outwards by the diaphragm spring (m). As the
throttle valve opens, actuating motion is transmitted to the pump by the pump
rod (T) and pump lever (L5), pushing the diaphragm inward against the fuel
and forcing it to pass through the pump jet (Gp) and the calibrated injection
nozzle (i) into the venturi, enriching the fuel/ air mixture and resulting in
smooth engine response at acceleration.
The check valve (Hl), in the pump inlet, prevents the fuel from backing up into
the float chamber; a second check valve (HZ), at the base of the injection
nozzle, prevents air from entering the pump through the injection nozzle when
the pump is on the inlet stroke.
The amount of fuel dispensed by the pump on its pressure stroke at time of
acceleration is predetermined by the length of the pump stroke; the stroke can
be adjusted through the pump adjustment (t). The pump jet and the calibrated
injection nozzle control only the duration of injection.
251
2.2.12 Check Valve
The check valve assembly (HI) has a return flow passage measuring O.36 mm
(0.0142 in) in diameter. This port prevents excessive enrichment of the fuel/
air mixture by fuel dispensed by the fuel pump during acceleration, that is,
depending upon the speed with which the throttle pedal is depressed, larger or
smaller amounts of fuel are permitted to flow back to the pump.
252
2.2.13 Carburetor Specifications
Carburetor type
Solex 40 P II-4
2 per engine
Venturi (K)
32
2 per
carburetor
Main jet (Gg)
0120
2 per
carburetor
Air correction jet (a)
180
2 per
carburetor
Idle metering jet (g)
57.5
2 per
carburetor
Idle air bleed (u)
1.8
2 per
carburetor
Accelerating pump
72
1 per carburetor
Pump jet (Gp)
50
2 per carburetor
Accelerating pump
nozzle
high -type with O.4 restrictor
2 per carburetor
Float needle valve
(spring -loaded)
175
1 per carburetor
Float
7,4 g
1 per carburetor
Emulsion tube
Nr. 25
2 per carburetor
Main jet carrier
6
2 per carburetor
Intermediate metering
ports
1.7; 1.4; 1.0
Injection quantity
(warm season)
0.45 cc (7.3 minims) from 2
strokes, each nozzle
2 nozzles per
carburetor
Injection quantity
(cold season)
0.65 cc (10.6 minims) per
carburetor from 2 strokes, each
nozzle
2 nozzles per
carburetor
The main jet size is of great importance when operating at considerably
varying altitudes for which the following rule-of-thumb may be applied:
Change main jet size by 60/0 for each, 1,OOO m (3.280 ft) altitude variation,
For example, normal jet size at an altitude of 400 m (1,312 ft) is 0120; proper
jet size for an altitude of 1,400 m (4.592 ft) is 0115.
253
2.3 REPAIR PROCEDURES
2.3.1 Removing and Installing Fuel
Line
1.
2.
3.
4.
Remove both air cleaners.
Detach fuel line from both carburetors by removing connectors.
Remove attaching clip from air blower housing.
Withdraw fuel hose from fuel pump.
Reassemble in reversed order of the above using new gasket and
attaching the fuel line so it does not touch the housing to ca use rattles.
254
Carburetor
Removal
1.
2.
3.
4.
5.
6.
7.
8.
Unsnap air cleaner fasteners.
Remove air cleaner.
Remove air cleaner base plate.
Detach carburetor linkage from throttle arm.
Detach fuel line.
Remove four carburetor retaining nuts from carburetor flange.
Withdraw carburetor.
Cover intake duct.
Installation
Install in reversed order of the above, making sure that the gaskets seat well
and the linkage does not bind.
Changing Air Cleaner Cartridge (KNECHT -Filter)
1. Remove center screw from filter housing top and pull out.
2. Withdraw filter housing top by pulling up.
3. Replace cartridge.
Reassembly
Inspect square plastic foam gasket, replace if necessary.
255
2.3.3 Cleaning Carburetor
1. Remove carburetor.
2. Wash carburetor with clean solvent.
3. Remove retaining screws from carburetor cover.
4. Withdraw carburetor cover, watch float pin retainers.
5. Remove float pin and float.
6. Remove main, idle, and pump jets.
7. Remove air correction jets and shake out emulsion tubes.
8. Remove power enrichment and idle air bleed jets.
9. Remove float needle valve assembly.
10.
Clean all jets and ports
11.
Reassemble carburetor.
The carburetor should be cleaned in a utensil containing clean solvent.
All jets and ports should be cleared with compressed air. In no case
should wire or other mechanical devices be used for cleaning the jets
because the calibrated orifices can be damaged or enlarged.
256
2.3.4 Disassembling and
Reassembling Carburetor
1. Remove carburetor
2. Remove retaining screws from carburetor cover, withdraw cover with
gasket.
3. Remove float with pin and intermediate swivel joint.
4. Remove four accelerating pump retaining screws and remove pump.
5. Remove main jet carrier with jets.
6. Remove idle air bleed and idle jets.
7. Remove air correction jets and shake out emulsion tubes.
8. Remove injection nozzle retaining screws and carefully withdraw the
nozzles making certain that nozzles are not bent in the process.
9. Remove both pump jets and accelerating pump check valve.
10.
Remove power enrichment jets.
11.
Remove idle mixture adjusting screws.
12.
Loosen preatomizer set screws.
13.
Pull out preatomizers by first freeing with a gentle twist.
14.
Loosen and remove venturi set screws.
15.
Pull out venturis by first freeing with a gentle twist and then
carefully lifting these out, making sure they do not bind.
16.
Remove burrs in venturi which were caused by set screw pressure.
257
2.3.5 Inspection and Reassembly
Reassemble in reversed order of the above by noting the following points:
1.
2.
3.
4.
5.
6.
Check float needle valve and seat for wear (leak test).
Fuel line connector threads in cover must not be damaged.
Check condition of gaskets, replace if necessary.
Ensure that accelerating pump diaphragm is in good condition.
Check float for leaks, replace of defective.
Ensure that all jets are of proper size by comparing specifications on
page F 11.
When replacing jets or check valves, ensure that only genuine SOLEXstamped parts are used. The parts are carefully calibrated to permit
precise settings and low fuel consumption.
7. Install venturis. When installing the venturis make certain that the
venturi throats face up. that is, the writing on the venturi tubes should
be seen from above. Firmly tighten venturi set screws but do not
overtighten.
8. Check radial clearance of throttle shaft. Excessive clearance allows false
air to pass through and impairs engine starting and idling. .
9. Inspect idle mixture adjusting screws; bent, burred, or broken needle
tips call for replacement of the screw,
258
2.3.6 Adjusting Injection Quantity
Special Tools:
P 25a Calibrated Vial
Adjustments
1.
2.
3.
4.
Adjusting idle speed.
Run engine to fill float chamber with fuel.
Stop engine, remove both air cleaners.
Work throttle arm until air bubbles cease to show at the pump injection
nozzle.
5. Hold calibrated vial (P 25a) at the tip of the nozzle and quickly move
throttle arm two times from stop to stop.
6. Check injection quantity, empty the calibrated vial, repeat procedure on
the second, injection nozzle.
7. Injection quantity from each nozzle on two pump strokes should be 0.45
cc (7.3 minimum) during the warm season, and O. 65 cc (10.6
minimum) during the cold season.
8. Check injection quantity in second throat.
9. If required, readjust injection quantity by resetting the adjusting nut on
the pump rod. If adjustment should not be possible due to lack of
threads, insert a spacer between the pump arm and the nut.
259
Note
Fuel squirting from the pump nozzle should not strike the pre-atomizer nor the
venturi and must pass through the slit between carburetor wall and throttle
valve,
1.
2.
3.
4.
5.
6.
Injection nozzle
Pre-atomizer
Venturi
Carburetor body
Squirting fuel
Throttle valve
Should it become necessary to bend the injection nozzle, insure that its tip
remains at same height. The pump jet does not affect the injection quantity.
Changes in size of the pump jet affect only the duration of injection since the
jet size controls the flow only in respect to flow duration. Injection quantity as
well as the moment of injection must be identical in all carburetor throats.
260
2.3.7 Adjusting Idle Speed
Special Tools:
P 227 Carburetor Synchronizer
Adjustments
1. Remove idle mixture adjusting screws and inspect needle tips for burrs,
grooves, and bends. Install new screws if in doubt,
2. Bring engine to normal operating temperature and remove air cleaners.
3. Detach throttle rods from throttle arms.
4. Uniformly turn idle adjusting screws in until engine idles at about 1,000
rpm.
5. Following any convenient sequence turn idle mixture screws fully in on
both carburetors - do not tighten since this can damage the needle
points - then back off 1 1/2 turns. From this position turn the screws in
or out until fastest idling speed is achieved, In no case should the screws
be left in fully turned-in position.
6. Adjust idle speed screws until the engine idling rpm drops to 800 - 900.
261
7. Place carburetor synchronizer (P 277) on carburetor throat and adjust
plunger glass to vertical position.
8. Turn adjusting disc in synchronizer until plunger moves to about halfway between two marking rings about midway of the glass tube length;
this accomplished, the synchronizer is set for the particular engine and
no further adjustments should be made with the disc in the synchronizer.
9. Place synchronizer (P 277) onto second throat of the carburetor
assembly; the plunger should move up to same point as during
procedure described above. If the reading is different, the throttle valves
are not in alignment and must be synchronized, which is easily
accomplished by twisting the throttle shaft. Using the synchronizer,
recheck synchronization of both throttle valves by comparing readings of
the synchronizer when placed first on one, then on the other throat.
10.
Without changing synchronizer adjustment. place synchronizer
onto throats of second carburetor assembly and adjust throttle valve
with idle speed screw so that the plunger in synchronizer moves to same
height as observed during test described in Pt. 9, above readjust throttle
valve if necessary,
11.
Should it be noted during the adjusting procedure that the idle
speed has changed, readjust idle speed screw settings and recheck
carburetor synchronization with the synchronizer, correct of necessary.
12.
Reconnect throttle rods to throttle arms.
NOTE ! Adjust carburetor rods so that these can be attached to the
carburetor arms without preload in relation to each other.
13.
Set idling speed to 1,200 - 1,300 rpm. Using the synchronizer (P
227) recheck synchronization of all throats as described in Pts. 8 and 9.
If the gauge does not show equal values in both carburetors, synchronize
these with each other by properly adjusting the carburetor throttle rods.
14.
Recheck idle speed.
15.
Check injection quantity (warm season 0.45 cc from each nozzle on
two pump strokes, 0,65 cc in cold season).
16.
Check accelerator pedal stop bolt and adjust if necessary. When
the accelerator pedal is depressed against the stop bolt, the carburetor
arm should be clearing the carburetor stop block by about 1 mm (.039
in).
17.
Install air cleaners with gaskets, tighten retaining screws.
262
2.3.8 Checking Carburetor Float
Level
Special Tools:
Special Tools: P 78 Float Level Gauge
Procedure
1. Place car on level base. 2. Remove main jet carrier from one carburetor.
3. Install float level gauge (P 78) in place of main jet carrier.
4. Start engine and allow to idle. When float level is correctly set, the fuel will
rise to a point between the marking rings on the gauge tube. If the fuel level
check is accomplished according to the above instructions, the need for a float
level readjustment will seldom occur. Whenever the float level deviates from
specifications, first check the float, float adjustment swivel, and the float
needle valve; thereupon proceed with steps required for readjusting the float
level by resetting the externally located float level adjusting screw.
Note :
Turn adjusting screw in to lower the fuel level, turn the screw out to raise the
level.
Apply the following procedure if the float level gauge (P 78) is not at hand:
1. Place car on level base.
2. Start engine,
263
3, Remove plug from the float level inspection port, When the float level is
correct, the fuel will be seen in the machined groove within the threaded part
of the port, or it will just begin to flow out.
4. Readjust float level if necessary.
Note :
Turn adjusting screw to lower the float level, turn the screw out to raise the
level,
Note
Turning the adjustment screw in causes the float to move downward which, in
turn, causes some of the fuel to run out through the inspection port. Therefore,
allow the engine to use up the fuel excess before making the final adjustment.
264
2.3.9 Removing and Installing Air
Cleaners
1. Detach carburetor heating hose,
2. Unsnap all four fasteners at the lower part of the air cleaner housing
(KNECHT-Filter),
3. Detach crankcase breather hose from the air cleaner housing.
4. Withdraw the air cleaner housing upward (KNECHT-Filter). Remove five
retaining bolts at forward air duct box and remove box (MANN and
HUMMEL Filter).
5. Remove retaining bolts from air cleaner base plate and remove plate
(KNECHT-Filter).
Installation
Install air cleaner in reversed order of the above, ensuring that the gasket
sealing surfaces are clean; use new gaskets if necessary.
265
Intake Duct
Remove
1.
2.
3.
4.
5.
Remove carburetor.
Remove spark plug connectors from spark plugs.
Remove side cover plate.
Remove retaining nuts and bolt from intake duct and withdraw duct.
Cover intake port in cylinder head.
Installation
Install intake duct by noting the following points:
1. Use new intake duct gasket. Make sure that the gasket matches the
contours of the intake port in cylinder head.
2. Place the graphite-coated side of the gasket towards the cylinder head.
3. Inspect intake duct for cracks.
4. Carefully and evenly tighten the intake duct retaining nuts and bolt.
5. Install new gasket between duct and carburetor .
Throttle Linkage
Remove
1.
2.
3.
4.
5.
6.
7.
Remove floor mat to gain access to opening in floorboard.
Detach throttle rod at ball joint of cross-shaft at air blower housing.
Remove gearshift lever base retaining screw (hex head).
Withdraw gearshift lever with base.
Remove handbrake lever with base.
Remove attaching clip of throttle rod through freed openings.
Detach throttle rod from rear cross-shaft ball joint joint (beneath
transmission).
8. Pulling rearward, withdraw throttle rod.
Installation
Note the following during installation: The ball joints and all moving joints of
the cross-shafts should be well lubricated. Ball joint lock nuts must be well
tightened.
266
2.3.12 Adjusting Throttle Linkage
The throttle linkage must be so adjusted that all throttle valves work in unison.
In addition it should be noted that the throttles do not bind throughout the
entire extent of travel from idle to full power settings.
Note
Smooth and even clowing action of the throttles can be achieved only when all
throttle linkage ball joints move freely. Lubricate the ball joints if necessary.
2.3.13 Carburetor Service Diagnosis
Chart
The chart applies only to carburetors which meet specifications shown on page
F 11.
Malfunction
1. Engine does not
start despite
properly functioning
ignition and
adequate fuel in
tank.
2. Uneven idling.
Possible Cause
Remedy
a) No fuel in fuel a) Clean main jets. Check fuel supply
system.
lines. Detach fuel line connecting
pump with carburetor, actuate starter
(ignition off). If fuel flows from pump,
float needle valve is plugged; if no
fuel flows from pump, possibly pump
check valves are stuck or pump
mechanism defective.
b) Carburetor
floods.
b) Check and clean float needle valve,
check gasket at float needle valve
assembly. Check float, replace if
defective. </TD< tr>
a) Improperly
adjusted idling.
a) Readjust idling.
b) Idle jets or
idle air bleed
plugged.
b) Clean idle jets or idle air bleed, as
required.
c) Leak in the
intake ducts.
c) Check intake ducts, flange
connections, and gaskets.
d) Defective idle d) Install new idle mixture adjusting
mixture screws. screws.
267
3. Poor power
transition (flat spot).
a) Idle
adjustment too
lean.
a) Readjust idling (check jets).
b) Improperly
set float level.
b) Readjust float level.
c) Improper
injection
quantity.
c) Readjust injection quantity.
d) Intake ducts
leaking.
d) Check intake ducts, flange
4. Engine stalls when Improper idle
throttle is quickly
adjustment.
closed.
Readjust idling.
5. Engine runs
unevenly, misses,
backfires.
a) Mixture too
rich.
a) Check fuel pump pressure. Check
float level. Check float needle valve.
b) Mixture too
lean.
b) Clean main jets. Check fuel lines.
Check float level.
c) Intake duct
leaking.
c) Check intake ducts, flange
a) High fuel
pump pressure
overriding float
needle valve.
a) Check fuel pressure.
b) Defective
float (leaking).
b) install new float.
c) Float needle
valve not
closing.
c) Check float needle valve.
6. High fuel
consumption.
268
2.4 FUEL PUMP
2.4.1 Fuel Pump Schematic
1. Fuel screen
2. Outlet valve
3. Upper assembly
4. Lower assembly
5. Oil scraper
6. Actuating plunger
7. Pump cover
8. Inlet valve
9. Diaphragm spring
10.
Plunger return spring
11.
Spring retainer
269
General
The fuel is pumped to the carburetors by a mechanical diaphragm pump which
is mounted on the engine crankcase. The fuel pump is actuated by an eccentric
machined into the distributor pinion shaft. The quantity of fuel delivered by the
pump is metered automatically in direct proportions to the amount of fuel
dispensed by the carburetors.
The fuel pump consists of an upper and lower assembly. The upper assembly
accommodates an inlet and outlet valve, and a fuel filter. The lower assembly
contains the actuating plunger. Located between both assemblies is a
diaphragm and diaphragm spring. The diaphragm is built up of several layers
of a fuel-proof material, and is sandwiched between two supporting discs which
are riveted to the plunger coupling; the diaphragm also acts as a gasket.
Function Description
The eccentric on the pinion shaft raises the diaphragm actuating plunger. The
plunger transmits the pressure to the diaphragm coupling, overcoming the
pressure of the plunger return spring but with the support of the diaphragm
spring. This forces the fuel contained in the pump to exit through the outlet
valve on to the carburetors. When the actuating plunger moves back with
further rotation of the eccentric, negative pressure is created in the chamber
above the pump diaphragm and fresh fuel enters the pump through the inlet
valve. This pumping action repeats with every revolution of the eccentric (once
every two revolutions of the crankshaft). The amount of fuel passing through
the pump is governed by the amount dispensed by the carburetors; that is,
only that amount of fuel can be pumped which is able to pass through the
more or less opened float needle valves in the carburetors.
270
2.4.2 Schematic of Manual Fuel Pump
Drive
1.
2.
3.
4.
5.
Fuel pump
Pump insulating flange
0 -ring
Actuating plunger
Distributor pinion shaft
271
2.4.3 Pump Side of Mechanical Fuel
Pump
1. Hex bolt
2. Gasket
3. Cover
4. Gasket
5. Fuel screen
6. Pump, upper assembly
7. Leaf spring valve
8. Valve limiter
9. Self-threading screw M 3x8
10.
Fillister screw with washer
272
2.4.4 Actuating Side of Mechanical
Fuel Pump
1.
2.
3.
4.
5.
6.
7.
8.
Diaphragm assembly
Coupling pin
Plunger
Diaphragm spring
Pump, lower assembly
Plunger return spring
Spring retainer
Lock ring.
273
2.4.5 Testing Pump Pressure
General
The pump pressure is determined by the degree of spring compression during
the intake stroke of the pump. The spring tension is so calibrated that it
allows,the fuel to enter the carburetor only as long as the float needle valve is
open. When the buoyancy of the float forces the float needle valve to close,
pressure builds up in the fuel line and pump fuel chamber shortening the pump
stroke. In normal operation, the diaphragm stroke amounts to only a few
tenths of a millimeter.
The lower assembly is vented through two orifices in the casting. Also, should
the fuel leak into this part of the pump, it can drain through the venting holes.
Testing
The pump pressure should be 0.20 to 0.24 atmospheres (2.9 - 3.5 psi) with
the float needle valve closed and engine running at 1,000 - 3,000 rpm.
Minimum fuel delivery should be 30 liters (7.9 US gal.) per hour, which equals
500 cc (16.9 us f1. oz.) per minute, at 4,500 rpm.
The simplest way to check the fuel pump pressure is with the aid of a pressure
gauge inserted into the fuel line between the pump and carburetor by means
of a T-joint. A fuel shut-off valve is incorporated in the fuel line behind the
pressure gauge.
Essential for proper pump pressure is correct spring tension and faultless
condition of the diaphragm and control valves.
Excessive pump pressure causes carburetor flooding and, in almost all cases,
leads to dilution of oil. Insufficient pump pressure causes lean combustion
mixture and, thus, a rough running engine with misfiring at high rpm and
decreased power output.
274
2.4.6 Removing and Installing Fuel
Pump
Removal
1. Remove fuel hoses from pump.
2. Remove pump shield.
275
3. Remove pump attaching nuts from flange.
4. Remove pump and insulating spacer.
Installation
Installation is accomplished in reversed order of the above. Ensure that the Oring is in good condition, replace if necessary.
276
2.4.7 Reconditioning Fuel Pump
Disassembly
1. Remove cover retaining hex bolt.
2. Remove cover and fuel screen.
3. Remove six fillister screws which secure the upper assembly, withdraw
assembly.
277
4. Rest the lower assembly of pump on the diaphragm supporting disc,
push spring retainer down with pliers, remove lock ring, spring retainer,
and spring.
5. Withdraw the diaphragm-plunger-spring assembly from lower pump
casting. Ensure that there is no grit around the lock ring groove in
plunger to prevent damaging the oil scraper.
6. Remove coupling pin from actuating plunger with a punch, detach
diaphragm from plunger.
278
7. Remove self-threading fillister screw from inlet valve and remove leaf
spring valve and valve limiter (outlet valve cannot be removed).
8. Clean pump components with gasoline.
Reassembly
following points:
1.
2.
3.
4.
Check outlet valve in upper assembly for proper functioning.
Check sealing surfaces of inlet valve.
Install leaf spring valve and valve limiter, check for proper operation.
Reconnect diaphragm with plunger with the pin, check free movement of
plunger in diaphragm coupling. Center coupling pin in plunger.
5. When mounting pump upper assembly. ensure that the diaphragm is not
creased. Evenly tighten screws in cross-sequence.
6. Check gasket at pump cover, replace if necessary.
279
3. Electrical System
3.1 ELECTRICAL SYSTEM
DESCRIPTION
Generator
A 12 volt, 300 watt generator is utilized, The alternator charges the battery
and supplies current to the electrical units of the car.
Engine Starter
An 8/10 HP - solenoid-operated starter is utilized. The starter is controlled by
the ignition/starter switch on the instrument panel.
Battery
The six-cell, 12 volt, 45 Ah battery is located within the luggage compartment
under the front lid. The negative battery terminal is connected to the ground.
Ignition System
The ignition system is battery operated and includes a high tension coil as well
as a distributor which is equipped with a centrifugal spark advance mechanism.
The distributor is driven by a worm gear mounted on the crankshaft, The
ignition current is switched on through the ignition switch on the instrument
panel.
Lighting
The two headlamps are mounted in the front fenders and have high and low
beams in each. Parking lights are accommodated in the front directional blinker
housings. The parking lights and headlights are switched on through a switch
on the instrument panel, next to the ignition switch, Instrument light
brightness can be varied with the light switch knob by turning it to the desired
position, Tail lights go on with headlights.
The headlights are dimmed with the blinker/dimmer/headlamp flasher switch
located on the steering post below the steering wheel. A blue headlamps
control light goes on in the tachometer dial when high beams are on,
The two tail lights are combined with stop lights and directional blinkers, Two
small lamps illuminate the license plate in the back,
The stop lights are controlled through a switch mounted in the brake master
cylinder and go on when the foot brake is depressed, The backup lights go on
when reverse gear is engaged; the lamps are located in the tail lamp housing,
the switch in the side of the transmission housing.
The interior lamps are located above the doors, The lamps can be turned on by
tilting the entire lens. In the same manner, the lamps can be set for courtesy
operating together with the opening doors.
280
The cigar lighter socket in the instrument panel can also be used for plugging
in a hand lamp.
Electrical Accessories
The signal horns can be sounded through a horn button in the center of the
steering wheel; the contact is made through a contact ring in the
blinker/dimmer/flasher switch.
The directional blinkers and head lamp signal flasher can be actuated through
switch lever in the steering post extension; the switch also controls the high
and low head lamp beams. Operation of the directional blinkers is indicated by
a green control light in the tachometer dial as well as through an audible
ticking noise in unison with the flasher.
The windshield wipers and washers are actuated through a combination
wiper/washer switch on the steering post. The fuses for the various accessories
are located in the left part of the luggage compartment and are covered with a
plastic top.
Instruments
The speedometer and odometer are driven by a gear in the transmission by
means of a cable drive. The tachometer is transistorized; electrical pulses
emanating from the ignition system pass through a transistorized con venter
and are fed into an electric counter in the tachometer unit.
The fuel level is indicated by means of a fuel gauge which is connected to an
electrical sending unit in the fuel tank. In addition, the gauge has a low fuel
warning light.
Note
Repairs in the electrical system normally are confined to the replacement of
worn or defective parts and the repair of the wiring system. In general,
damaged wiring removed from the system should be replaced wire of same
cross-section as shown in the wiring diagram. BOSCH components should be
repaired by BOSCH service whenever possible.
Caution
To avoid shorting the circuit and minimize fire hazards due to electrical sparks,
the battery ground strap should be removed from the battery prior to the
initiation of any work in the electrical system.
281
3.2 LAMPS AND FUSES
1. High beam, left
2. High beam, right High beam indicator
3. Low beam, left
4. Low beam, right
5. Parking lamp, left
6. Parking lamp, right
7. License plate lamp and luggage compartment lamp
8. Fog lamps
9. Windshield wipers and washer
10.
Auxiliary combustion heater
11.
Interior light, cigar lighter, electric clock
12.
Stop lights, blinkers, backup light
282
Bulb Chart
All bulbs 12 volts
Qty
Nomenclature
2
Twin filiament headlamp bulbs
45/40
W
2
Sealed beam inserts (US made)
50/40
W
4
Cartridge bulbs for parking and license plate lamps
4W
2
Cartridge bulbs for parking lamps (Italy)
3W
4
Single filiament bulbs for directional blinkers
18 W
4
Single filiament bulbs for directional blinkers (Italy)
15 W
(6)
Wattage
Single filiament bulbs for directional blinkers and backup lights
(USA)
32 cp
(2)
Twin filiament bulbs for stop and taillights (USA)
32/4 cp
2
Twin filiament bulbs for stop and taillights
18/5 W
2
Single filiament bulbs for backup lights
25 W
2
Cartridge bulbs for interior lights
10 W
1
(2)
Single filiament bulb for luggage compartment light 5W . 16
Bulbs for instrument illumination and control lamps
Single filiament bulbs for parking lights (USA)
283
2W
2 cp
3.3 GENERATOR DESCRIPTION
General
The generator has the function of supplying all the current consuming units in
the vehicle and to charge the battery satisfactorily. It is driven by the engine
by means of a V-belt. To regulate the voltage which varies according to the
loading of the generator by the current consumers or by the varying speed of
the engine there is a toggle regulator with a sloping characteristic curve.
Method of operation
The generator is a DC shunt-wound machine. Its voltage is maintained at
approximately the same level by means of a electro-magnetic high speed
regulator independently of engine speed and loading. In addition this regulator
prevents overloading of the battery. An electro-magnetic switch switches the
generator on automatically and at low speeds disconnects it from the battery
so that discharge of the battery through the generator is prevented. Regulator
and switch are combined to form a regulator switch.
In order to protect the generator from overloads resulting from the very high
charging current occurring when current consumers are switched on the
battery is flat and the voltage constant, regulators with output limitation are
used.
Variode regulator
The variode regulator fitted in the vehicle has on the voltage regulator unit a
second winding (control winding). This is connected on one side to the switch
contact and on the other side via the variode (semiconductor unit) to D+.
When current flows through the main current lead a potential drop arises
between D+ and the switch contact. When the output limit of the generator is
reached the variode becomes conductive as a result of the potential drop. In
the, control winding flows a current which strengthens the magnetic field on
the voltage regulator unit and thus reduces the generator potential. The
generator is thus protected against overload.
Construction of generator
The main components of a generator are:
The pole housing with pole shoes and the exciter, winding
the armature with armature winding and commutator
the carbon brushes and brush holders
the bearing cap (drive bearing and commutator bearing)
the special regulator switch
The pole housing is a hollow cylinder of special iron which forms a very good
conductor for the magnetic flux. The pole shoes are fixed on the inside of the
housing by means of countersunk bolts into the housing.
284
On the pole shoes are located exciter coils connected in series which consist of
a large number of windings of insulated copper wire.
Between the pole shoes rotates the armature, an iron core in which are bedded
the windings (armature conductors) of the armature coil and on whose shaft is
also fitted the commutator (current reversal switch) from which the induced
generator potential is collected.
The iron core of the armature is made up of a large number of thin stamped
out metal plates which are insulated from each other for suppression of eddy
currents. The armature coils which consist of a fairly large number of windings
of insulated copper wire are located and insulated in the grooves of the
armature. The armature conductors are protected against centrifugal throwout. The total number of all the coils is called the armature winding which
consists of as many coils as the commutator has segments, To ensure that all
commutator coils are conductively connected to each other and thus always
contribute collectively to the production of the generator potential the end of
one coil is soldered into one of the commutator segments with the beginning of
the next coil. Thus a closed circuit armature winding is effected.
The commutator consists of copper segments which are insulated from each
other and from the armature shaft. The insulators between the individual
segments must be recessed back from the commutator surface so that the
carbon brushes will only run on the copper even after a considerable period of
operation.
The carbon brushes are pressed against the commutator under uniform spring
pressure and collect the current produced in the armature coils. The carbon
brushes locate in box shaped brush holders.
The armature shaft is mounted in ball bearings on both sides. Both the bearing
caps, that of the drive bearing and the commutator bearing seal off the pole
housing from outside. The commutator bearing is covered by a cover strip so
that the generator will be easily accessible for servicing of the carbon brushes
and the commutator.
285
Maintenance
The ball bearings in the generator are packed with ball bearing grease (e. g.
Bosch FT IV 33) and normally require no attention. Repacking with grease,
which under no circumstances should be done with normal lubricating grease,
will normally only take place during the course of an engine overhaul.
Approximately every 10,000 km (6000 miles) the cover strap should be
opened and the carbon brushes checked for wear and free travel. Used brushes
should be replaced. The carbon brushes should not be oiled.
286
3.3.1 Changing Ignition Warning
Light
General
The ignition warning light (red) is connected between the B+ terminal and 61
of the regulator switch of the generator and lights up in the combination
instrument on the instrument panel when the ignition is switched on. After
starting the engine the light will go out as soon as the increasing charge
voltage of the generator is equal to the battery voltage.
Testing
Switch on ignition, the ignition warning light dh the instrument panel must
light up. Undo generator cable from terminal D+ 61 on regulator, the light
must go out. If this is.not the case the cable is shorting to earth and this fault
must be rectified. Reconnect cable to terminal D+ 61,
The light serves at the same time as a check on the V-belt and thus also on
the cooling fan. If the V-belt breaks the generator and fan will remain
stationary and the light will come on.
Changing the bulb
1. Pull out bulb with holder.
2. Push bulb slightly into holder rotate slightly and withdraw.
3. Fit new bulb in reverse order.
287
3.3.2 Checking the Generator
Remark
For checking the electrical system the following test instruments are required:
One Voltmeter range 0 - 20 Volts
1. One voltmeter range 0 - 20 Volts.
2. One ammeter range 10 - 0 - 60 Amps.
3. Load resistance (adjustable) of 500 Watts nominal capacity.
Note
Extinguishing of the ignition warning light after starting and with increasing
engine speed gives no guarantee for charging of the battery. If the wiring
system is in order incorrect charging of the battery, i.e. excessive or too little
charging current, will be indicated by bad starting, weak headlamp illumination
when starting at night. Abnormally high water requirement by the battery
should lead one to suspect excessive charging current, checking can be carried
out initially without removing the generator or having to uncover the regulator.
In the first instance the condition and tension of the V-belt should be checked.
Regulator Voltage No Load
1. Undo battery lead from terminal B+ on regulator and temporarily
insulate cable shoe. The positive lead of the voltmeter should be
connected to termianl "D+ / 61" and the negative lead to earth.
2. Start the engine and run the generator up to double the rated speed, the
voltmeter must then show the correct regulator voltage.
If the prescribed voltage is not reached generator and regulator should
be overhauled.
Regulator voltage on load
288
1. Connections as in Fig. 5 but the A. M. should be connected in series with
the control resistor between terminal B+ on regulator and earth.
2. Start engine, increase speed up to generator test speed and keep
constant. Adjust resistor until the A. M. indicates the corresponding test
voltage. At this setting the voltmeter must indicate at least 12 V with a
generator in good condition.
3. If during this test the generator gives off no current it must be removed
and repaired.
289
3.3.3 Removing and Refitting
Regulator Switch
Removal
1. Disconnect battery.
2. Remove leads from regulator.
3. Undo fixing bolts and detach regula tor.
Refitting
The following should be noted:
1. When exchanging the regulator first check that there is no short to earth
in the field coils of the generator.
2. Connect cables as per wiring diagram on regulator housing.
3. Polarise generator (see 5 LI note).
4. If incorrect values are obtained even after fitment of a new regulator
either the generator or the wiring system is not in order and a Bosch
service station should be contacted.
3.3.4 Checking Carbon Brushes and
Commutator
1. Undo cover strap of generator.
2. Check carbon brushes for wear and free travel in the brush holder
guides. Brushes which completely disappear into the brush holder are
worn and must be replaced; the same applied to brushes which have
become heavily oiled.
3. If the commutator is oily or greasy it can be cleaned with a clean cloth
which has been soaked in petrol and wrapped round a piece of wood,
When doing this care should be taken to ensure that no dirt gets into the
ball bearing.
4. Check the pressure springs for tension (see electrical data) if necessary.
replace defective springs.
5. If the commutator surface has become uneven as a result of running in
of the brushes or has burn spots, it should be skimmed.
Note
Any petrol on the commutator should be allowed to evaporate completely
before start-up (fire risk).
290
3.3.5 Removing and Refitting
Generator
Removal
1.
2.
3.
4.
5.
Disconnect cable at generator.
Detach V -belt.
Remove clamp strip of generator.
Undo fixing bolts on generator bracket.
Undo four bolts on fan cover and extract generator.
Refitting
When refitting the following should be noted:
1. Ensure satisfactory condition of paper gasket on the generator bracket at
the crankcase.
2. Reconnect leads in accordance with wiring diagram.
Note:
Before fitment of the V -belt the generator should always be polarized to
prevent any damage to the regulator and to ensure correct charging, For this
purpose one should connect the battery lead for a short time to the terminal
61 D+ on the regulator, The generator must now start to run as an electric
motor i,e. in the direction of rotation of the engine.
3.3.6Dismantling and Reassembling
Generator
Dismantling
1.
2.
3.
4.
5.
Detach V-belt pulley and cooling fan.
Undo field coil connection from brush holder of positive brush.
Undo both generator housing bolts.
Take generator housing apart and extract armature.
Pull out ball bearings, After dismantling individual parts wash carefully in
petrol and blow through with compressed air.
Reassembling
Reassembly should be effected in the reverse order observing the following
points:
1. Check armature, field coils, cable connections and brushes,
2. Check ball bearings for wear and damage and replace if necessary. Wash
bearings carefully in petrol and pack with Bosch grease Ft 1 V 33.
3. Ensure correct connection of leads to brush holders,
291
3.3.7Checking Armature
Armature faults are in many cases not externally visible. Checking should
include tracing of open circuits as well as winding and earth shorts.
1. Open circuits are generally recognizable on the commutator by burn spots
between two segments. They can also be measured with a sensitive resistance
measuring bridge.
2. Winding short circuits between windings of an armature coil can be traced
on an armature test meter. The armature is rotated between two test probes,
a magic eye then indicates the winding short circuit. Another instrument
consists of an AC magnet with two jaws which take the armature. Here the
armature is slowly rotated about its axis a thin piece of steel sheet being
placed on top of the armature. If there is a short circuit in the winding the
sheet of metal will begin to vibrate violently at 2 or more places around the
periphery of the armature. With another instrument the armature is rotated in
the same way over the jaws of an AC magnet while the tester probes the
commutator core with a probe.
The alternating current produced in the coil of the probe as a result of
induction from a winding short circuit can be heard in the test head phones as
a humming noise.
292
3. A short to earth will occur if the armature core is shorted to the winding or if
carbon dust ha s penetrated into the winding. The test should be carried out
with a test lamp of 40 V between armature iron and commutator. The test
lamp should not light up.
4. If the commutator is oval or is rough as a result of burn spots or grooves
have occurred as a result of running in of the carbon brushes it must be
skimmed and polished which is essential to obtain a satisfactory surface.
The insulators between the segments should be reworked with a commutator
saw until they are recessed back about 0.3-0.5 mm from the contact face of
the commutator.
293
Both field coils should be checked for open circuit, winding and earth shorts.
1. Check each field coil separately for open circuit connecting its ends with
a 12 V test lamp in series with the battery. In the case of open circuit the
test lamp will not light up.
2. Winding shorts can be checked by connecting the ohmmeter with the
ends of each coil and comparing the test result with the recommended
values (see electrical data). If an ohmmeter is not available one should
connect a 12 V battery in series with an ammeter to the coil ends and
should then compare the current intensity at the coils, If the current
consumption difference between the two coils is greater than 0,5 Amps,
the coil with the higher reading has a short circuit.
3. One should check the coils for short circuit to earth by connecting a 40 V
test lamp to one end of the field coil and the generator housing. The test
lamp should not light up.
4. The field coils should also be checked for satisfactory electrical and
mechanical contact with each other.
294
3.3.8 Generator Faults and their
Elimination
The red ignition warning light on the combination instrument should light up
when the ignition is switched on and should go out after the engine has started
and the engine speed has begun to rise.
The possible causes of trouble are summarised below:
Fault
Warning light does not
come on when ignition is
switched on
Cause
Remedy
a. Battery flat
a. Charge up battery
b. Battery defective
b. Renew battery
c. Bulb burned out
c. Renew bulb
d. Battery terminal
corroded or loose
e. Cable loose or
broken
e. Tighten cable or repair
f. Ignition switch
defective
f. Renew ignition switch
g. Generator brushes
are not running on
commutator
Ignition warning light
does not goout when
engine speed rises or
flickers, glows
g.Free carbon brushes or
renew or replace pressure
springs. Do not oil carbon
brushes!
a. V -belt loose or
defective
a. Tighten or renew belt
b. Regulator switch
defective
b, Exchange regulator switch
c. Charging lead
loose or broken
c. Check cables and
connections
d. Generator
defective
d. Check generator
e. Ignition switch
lead has bad
connection
e. Tighten connections
Ignition warning light only a. Generator
goes out at high engine
defective
speeds
b. Regulator switch
defective
Ignition warning light
d. Clean connections and if
necessary tighten up
a. Short to earth in
295
a. Check generator, repair
b. Exchange regulator switch
a. Eliminate earth short
continues to burn after
ignition switched off
cable or warning light
3.4 Engine Starter Description
General
The purpose of the starter is to start the engine, Type 911 and 912 cars are
equipped with a starter of 0,8 HP rating, designed for 12 V systems. The
starter has a helical spline drive with a self-releasing pinion (BOSCH Type EB).
As in most cases, the starter is a DC motor. It provides a considerable amount
of torque needed for turning the crankshaft at speeds needed for starting the
engine and with enough force to overcome the initial resistance on the
compression stroke.
To obtain the necessary torque from a starter and battery of proportionately
acceptable size, the starter drives the starter ring on the flywheel with a small
pinion. The gear teeth in the starter ring and starter pinion are beveled on one
side to make engagement smoother,
296
Due to the high gear reduction ratio between the starter ring and pinion, the
pinion cannot remain engaged with the starter ring longer than necessary since
the armature would be forced to spin at excessively high revolutions.
Therefore, the connection between the armature and starter ring must be
automatically interrupted as soon as the engine has fired up. In the BOSCH
helical spline starters the interruption is accomplished by means of an
overrunning clutch situated between the pinion and armature. The clutch
breaks the connection as soon as the engine speed becomes higher than that
of the starter. A coupling, which rides on the helical spline shaft of the
armature, is connected with the pinion through the overrunning clutch. Located
on the coupling is an actuating sleeve which can slide back and forth. A forkshaped end of the actuating lever is constantly engaged in the actuating
sleeve. The actuating lever moves the locking ring forward. Balls located in the
coupling bores are freed and the pinion is free to move towards the
engagement phase. When moving forward, the pinion rotates on the helical
splines. The application of thrust and rotation prompted the designation as
helical spline starter.
Operation
When the starter/ ignition key is switched on for starting, the starter solenoid
is energized, The actuating lever pushes the actuating sleeve and the locking
ring against the engagement ring; through this action, the engagement spring
is tensioned,
When the locking ring has moved forward by about 1/8 in. (2 -3 mm), the balls
located in the bores of the coupling are freed and can slide out of the shaft
groove into the enlarged part of the locking ring. Thus the engagement
components are freed and the fork begins to move the pinion; being
mechanically connected to the helical splines, the pinion "bores" itself with a
turning motion into the teeth in the starter ring on the flywheel. A t this time,
the switch in the solenoid closes and, simultaneously, energizes the main field
windings, causing the armature to turn. As the armature proceeds to turn, the
effect of the helical splines further presses the pinion into the starter ring up to
the point where the balls come to rest against the flanks of the helical spline
portion on the armature shaft.
The actuating lever, also mechanically connected to the engagement
297
components, is dragged along in the forward direction and tensions the
disengagement spring located on the drag link of the solenoid switch. If, for
instance, the pinion should be stuck due to gear tooth pressure in cases where
the engine fails to fire up, the disengagement spring makes the solenoid
plunger move back enough to open the switch contacts when the starter switch
is released.
As a result, the starter is deenergized, gear tooth pressure ceases, and the
pinion is drawn back through spring tension.
Normally, the pinion leaves the starter ring when the starter switch is released
due to spring force exerted by the solenoid return spring which travels the
distance allowed by the disengagement spring. This occurrence is further
supported by the fact that the overrun clutch breaks the torque transmitting
connection between the pinion and armature shaft when the engine begins to
turn faster than the armature. This also protects the armature from overspeeding.
Under the pressure of the engagement spring, the balls return into their
groove in the shaft. The engagement spring decompresses further and pushes
the locking ring over the balls. The brake disc is pressed against the brake pot
of the armature and, at the same time, the balls in the coupling bores are
pressed against the edge of the resting groove in the armature shaft. The
decelerating armature is thus braked under the pressure of the engagement
spring, further supported in this by the solenoid return spring.
298
4. Rear Axle and
Transmission
4.1 ADJUSTING GEARSHIFT LINKAGE
4.1.1 Remove Cover
•
1. Remove retaining screws from cover in rear of center tunnel and
withdraw cover.
4.1.2 Loosen Hex Bolt
•
2. Loosen hex bolt in shift rod clamp.
299
4.1.3 Set Selector
•
•
•
•
3. Move selector shaft of internal shift lever in transmission all the way
left to stop while in neutral position.
("Right" or "Left" is in direction of travel)
4. With transmission in neutral, move the gearshift lever to the right to
stop.
5. Tighten hex bolt of clamp to 2.5 mkp (18 lbs/ft). (Insert serrated
washer under the hex nut).
6. Check adjustment by shifting all gears. Also check play in the gearshift
linkage.
(Gearshift level play should be the same in all gears in all directions).
300