VW Trends December 1990

CORRADO
.Z.O--LITER
BUILDUP
BU/LD/116 THE AI'S 2.0 LITER
by Henry Z. De Kuyper
S
ince their beginning 15 years
ago, Automotive Performance
Systems has been dedicated to
one thing, to design the ultimate in
high performance components for the
second generation liquid-cooled Volkswagens. Anytime Volkswagen changes
one of their models, the APS research
and development team is right there,
testing every product under road conditions and on their dyno, for up to
a year, to insure that every part meets
their high standards.
APS was first in the industry to
build up the 2-liter 16V Oettinger
head fitted on their Rabbit in 1981.
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Since then they have been continuously
developing product lines for the Scirocco, Golf, and Jetta, and now Volkswagen's new flagship sports car; the
Corrado. For over a year now, Aaron
Neumann and his staff have been
developing the Corrado to be the ultimate car for the road. They started
by making the N euspeed sway bars,
springs and strut tie-bars. Then, they
installed the Kamei X1 body kit; a
complete leather interior, complete
with Flofit seats; and the Neuspeed
steering wheel and shift knob.
After the styling and suspension
modifications were complete, Aaron
moved on to the engine. Since nobody
else was doing any experimenting with
the Corrado engine, Aaron and his
team of experts embarked on their
quest to increase the power out of the
Corrado's engine. F irst, he did some
experimenting with fuel enrichment
and exhaust modifications along with
different pulley sizes to adjust the
proper boost pressure which APS calls
their Stage II kit. Then a Neuspeed
260-degree Sport Cam was later added
to the already installed Stage II kit
to widen the car's power band. One of
the factors that separates APS from
its competitors is that Aaron and his
team are never satisfied. Once they
achieved their goal with the midrange
In the block, grooves were ground Into the side to clear the rod nuts,
since they come very close to the block, due to the increase In stroke
from 86.4mm to 94.5mm. Techtonlcs recommends doing a trial
assembly and mark the block where the rod hits. This might take a
few tries, but the rods must clear the case by at least .040 to
.060-inch. All the grooving on the block has to be done by hand. lbu
can remove more material than the .040-.060-inch, but you have to be
careful that you don't gouge all the way through the side of the case,
since it varies in thicknesses as thin as an 1/8-lnch.
This shows the clearancirig for the oil pump for the #4 rod since it
comes very close. Clearancing also has to be done where the oil pump
is -mounted.
The bottom of the bores have been clearanced for the side of the
rods, since they slightly hit the side of the bore. The bottom of the
bore has to be relieved for the rod clearance. It is very hard to see if
the rods clear upon trial assembly, but you want to have at least .040
to .060-inch clearance.
Before the cylinders can be bored out, a 2-inch thick honing plate has
to be installed along with a head gasket in between the honing plate
and the head, then install the stock length head bolts with spacers.
Torque them to the proper torque spec that is recommended for your
application. This assures a round bore while the head is torqued, this
also assures that the bore will measure square when the plate is
unbolted.
RIGHT - The heads of the small bolts that
hold the piston squirters in place need to be
machined to a thinner height, or thickness.
Also where the piston squirter is mounted,
some material has to be machined down for
rod clearance.
and top-end performance for the Corrado, they set out to increase the
power on the lower end of the car's
powerband. To accomplish their goal
of building the ultimate 2.0-liter
engine, they enlisted the help of Darrell Vittone of Techtonics, located in
Riverside, California. So let's take a
look at what it takes to increase the
standard 1.8-liter Corrado engine to a
high performance 2.0-liter engine.
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When assembling the APS 2.0 liter engine, Techtonics used Race Tech Engineering head studs. The advantage of using Race Tech studs over the
stock bolts is that a bolt will flex and twist under torque since you are twisting the entire bolt. With the stud installed, you are torquing only the
nut itself and not the entire bolt. Also, with the finer threads you are able to get more of an accumte torque spec reading. Race Tech recommends
using a light coat of teflon based liquid pipe sealant on the coarse threads before installing it into the block. The sealant will hold the stud in
place when you remove the nut and washer at a later date. DO NOT USE LOCTITE ON ANY OF THE THREADS. The studs should be threaded by
hand until they bottom. After the studs have been installed correctly, use regular engine oil to lubricate the stud, nut and washer before assembly.
Torque the nuts using a V.-inch 12-point American style socket in three increments using the torque pattern In the VW service manual step 1, 40
lbs. ; step 2, 50 lbs.; final torque, 58 lbs. After torquing the head into place, run the engine until it reaches normal opetating tempemture, shut it
off, allowing it to cool and re-torque to 58 lbs.
0
The main bearing bolts were replaced with Race Tech 's studs for the same reason as the head bolts. Before the main bearing studs can be
installed, the cap hole threads have to be cleaned with a 10x1.50mm tap and then blown clean using compressed air. Install the studs into the
block by hand until they bottom, it is not recommended to use any sealant or lubricant on the coarse threads. DO NOT USE ANY LOCTITE ON
ANY OF THE THREADS. The four short studs go in the #1 & #5 bearing cap. Make sure to carefully check for cleatance at the interface between
the stud, nut, and oil pan. The eX1ta stud length on main bearing caps #2,3 and 4 is for the attachment of windage tmy devices. After t/Je studs
have been Installed, engine oil should be used to lubricate the rest of the pieces. For the best in performance, align the main bearing cap with the
upper bearing saddle in the block. The nuts use 7116-inch 12 point socket, torque the nuts in three increments using the torque pattern found in
the VW factory service manual. Step 1, 35 lbs. ; step 2, 45 lbs.; final torque, 55 lbs.
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VW TRENDS / DECEMBER 1990
Techtonics used a 94.5mm stroke crankshaft
that was manufactured in West Germany by
Oettinger (" Okrasa" ) and was imported by
Power Haus Products. It is a chrome-moly
steel forging, fully counterweighted, superfine
balanced and has nitrided (a hardening
process) bearing surfaces and the rod bearings
are 47.8mm. The oil holes were also chamfered
to allow a smoother flow of oil.
7. ROD BOLTS
Reusable 1.8-liter ARP rod bolts were installed
instead of the stock Corrado rod bolts. The
advantages of using the ARP bolts over stock
is that they are stronger and also reusable.
The standard 1.8 rod bolts have to be replaced
every time you pull the cap on. the rod.
The rod on the left is from the 1.8 liter engine that is used in the APS engine. The rod on the
right is the standard Corrado rod which which has a 86.4mm stroke and is very similar to a 1.6
liter rod. The 1.8 liter rods were modified to keep the compression within reason . The offset of
the wristpin bushing was lowered .040-inch. The wristpin bushing was offset to retain the 8.3:1
compression ratio, this was done to compensate for the longer 94.5mm stroke, versus the stock
86.4mm stroke,. The ARP bolts were Installed after all the machine work was done. The grinding
on the rods in photo 8 is so the rod will clear the bolt for the piston squlrter.
The head gasket used for the 2.0 liter APS engine Is thicker and has a relnfor6ement in between
the bores for head gasket blowing prevention.
B. PISTONS
The pistons used, are the stock factory 2.0
liter pistons with a 92.8mm crank that
produces 8.3:1 compression.
The difference between the Corrado hydraulic head and the normally aspirated 8-valve head Is
that the Corrado head has more heat treating, thus making It stronger. Techtonlcs also retained
the stock sized 40mm Intake and 33mm exhaust valves for reliability, but sodium filled exhaust
valves are used to deal with the extreme heat the supercharger produces. Techtonlcs ported the
head for better fuel and air flow. A three angle valve job was performed, consisting of some
precision cuts to the valve seat. The intake valve seats were cut with a main angle of
45-degrees, then the rest of the seat Is tailored to the desired margin by cutting with the other
two angles at 15 and 60-degrees. The exhaust valves seats were cut with a main angle of
45-degrees, then the rest of the seat Is tailored to the desired margin with 30 and 60-degrees
cuts to the other two angles. This helps Improve Intake flow and gives a precision seat margin.
Then the Intake valve was back cut to Increase air flow.
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12. OIL PAN
Neuspeed decided to replace the stock camshaft with their own Sport
Cam that was specially designed for the supercharged Corrado engine.
The Neuspeed Sport Cam has a .420 lift and 260-degree duration. All
Neuspeed Sport Cams are produced and semi-finished in Germany in a
special chilled cast iron. With the Neuspeed Sport Cam you 'll never
have to worty about premature lobe or lifter wear. Neuspeed finish
grinds the lobe profile for our U.S. style of high-performance street
driving without sacrificing driveab/1/ty.
13. INTERMEDIATE SHAFT
The stock 4.3 quart oil pan was replaced with a Neuspeed German
aluminum 4.7qt. oil pan. The advantages of the Neuspeed oil pan is
that It has a larger oil capacity, plus better cooling due to the cooling
fins on the bottom of the pan. The Inside of the Neuspeed oil pan has
baffles to get the oil back to the pickup more quickly, thus helping to
prevent oil starvation at the higher rpm 's.
The gear on the Intermediate shaft was ground down to a width of
5.5mm to clear the #4 connecting rod. The fuel pump lobe was
completely removed and the whole Intermediate shaft was machined to
make the shaft even and smooth, since the original casting is rough.
The oil pump shaft on the bottom, was ground down to 11mm to clear
the #4 connecting rod.
RIGHT - The complete APS 2.0-liter, future plans from APS include a
6800 rpm kit for the 2.0-liter Corrado and the stock Corrado. This kit
will become available by the time this article goes to press.
A.Fl.S. CORRADO ROAD H.Fl. STAGES
RPM
Stock
1.8L NEUSPEED STAGE II
KIT STOCK CAM
1.8L NEUSPEED STAGE II
KIT NEUSPEED
26-DEGREE CAM
2.0L 2021CC NEUSPEED
STAGE II KIT NEUSPEED
260-DEGREE CAM
55
94
2000
37
46
46
3000
66
77
4000
90
111
79
115
134
5000
114
135
139
150
5500
120
140
146
160
6000
118
130
145
155
MAX
PSI
9
14.5
13
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(ALL H.P. CALCULATIONS ARE FROM RESULTS SUPPLIED BY APS TESTS ON THEIR CHASSIS DYNO.) (THE
G60'S BOOST PSI WAS CALCULATED AT REDLINE)
Continued on page 93
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C 0 R R A D 0
2.0-LITER
BUILD
UP
Continued from page 78
SPECTRO OIL
Inside the engine, Aaron decided to use
Spectra brand oils because of their superior
lubricating capabilities. Aaron used Spectra
20w50 Golden Motor Guard which incorporates
a blend of diester/PAO synthetics and
petroleum based oils with advanced additive
technology that yields excellent performance
with regards to wear and oxidation. The
Golden Motor Guard formulations possess low
volatility and high film strength that out
perform standard mineral oil. The transmission
oil used is the Spectra 75w140 GL-1 which is
entirely synthetic. By adding the Spectra oil,
the transmission shifting became much easier
due to Spectra's ability to provide tremendous
lubrication protection in extreme heat
conditions. Some of the other advantages of
the Spectra transmission oil is that it reduces
wear and dramatically reduces drag In all
temperature ranges. The final Spectra product
used is the Spectra ~ar- Round super
coolant/anti-freeze. The Spectra ~ar-Round Is
a specially formulated pre-mixed solution. The
mixture features a non-corrosive formulation of
polyethylene glycol, mixed with specially
filtered water and an additive to enhance the
thermal conductivity of the coolant. The
Spectra ~ar-Round Is a complete " ready to
pour into the vehicle" formula, requiring no
water and Is non-corrosive to aluminum blocks;
plus, it helps prevent radiator system clogging
and vapor lock.
SOURCES
Techtonics
1253 West La Cadena Drive,
Dept. VWT
Riverside, CA 92501
(714) 788-4116
Race Tech Engineering
11320 Brydan Dr., #222, Dept. VWT
Taylor, Ml 48189
(313) 946-4477
Spectro Oils
9155 Archibald #304, Dept. VWT
Rancho Cucamonga, CA 91730
(714) 989-7070
VW TRENDS/DECEMBER 1990 93