Quark Newsletter.qxd - The Judson Register

To Cut or not to Cut?
Judson Rotors & Vanes
Decals & Badges
FAQs Update
VW JUDSON REGISTER NEWSLETTER
2
FEBRUARY 2005
In This Issue
Editorial - John's view of the Judson world……………………………………………....………………3
Website Search - Addition of "Google" Site Search Engine…………..............……4
Sad Loss - A well-established magazine goes to the wall……….......…………………………4
Judson Performance - A quick and easy start-point……...........……………………………….4
Decals & Badges - What's Judson & What's Not……………………….....…………………………5
FAQs Update - Opinions change in response to experience…...................................6
To Cut or not to Cut?-Some Judson owners have a tricky decision to make....…8
Would you dare? - Running without an Oiler……………………………………………………..10
Mystery Judson - Did Judson make a Roots blower?...........................................10
Judson Rotors & Vanes - We take you to the heart of the matter........................11
Another Judson Magneto? - or another Judson Mystery..................................... 12
Membership - 500 up........................................................................................................12
Classifieds - A selection of "For Sale" and "Wanted" items…………....................14
Front Cover
Top…John's VWType 1 Judson fits snugly (just) under the decklid.
Bottom…Andy Bye's VW Type II needs a shoehorn to fit it in his VW Bus.
If you would like to submit a Judson related article to "The VW Judson Register Newsletter" or to respond
to articles that appear in this edition please feel free to do so. Articles can be submitted as a "Word" document or as a simple text file. Pictures illustrating your article would be a great help.
Just email John at: info@vwjudsonregister.org.uk
Articles and images printed in this Newsletter remain the property of John E. Moxon
and/or the contributing editor.
You may download and print out a limited number of copies of this Newsletter under the strict understanding
that they should not be printed or re-distributed for financial gain. If you wish to reproduce any article or
quote from an article, before doing so please contact John at:
info@vwjudsonregister.org.uk
FEBRUARY 2005
3
VW JUDSON REGISTER NEWSLETTER
Editorial
F
irst of all can I welcome
you to the new style VW
Judson Register Newsletter,
I hope you like it. I've long
considered changing its format to a downloadable .pdf
but I always "chickened out"
as it meant learning and getting my head around something new…my learning curve
seems to get ever steeper as
I get older.
As you can see the newsletter is in glorious colour.
Ever the egotist I thought you'd like to see my VW
engine on the first front cover but you'll also notice
Andy Bye's Bus engine with his solution to restricted
space when running a Judson (more later in this
newsletter).
As you read the articles you'll notice an appeal at the
end of most topics for your experiences, opinions or
technical knowledge. That's why the site is here, not
to collect serial numbers of superchargers but the
knowledge of those who use them.
Information archived on the website is just "the tip of
the iceberg" as, with over 500 members the major
resource is the information you keep inside your head.
If you can add anything to any of the subjects you find
in this newsletter or would like to write an article on a
Judson related topic…get in touch.
We particularly need to hear from people who are successfully overdriving their Judson powered cars…VW,
Sprite, TR, Mercedes, Volvo all of them, we don't discriminate.
Just after Christmas I received some very sad news
from our “Techie Man” Richard Tricker. On the 2nd
December Richard’s Mother had died suddenly from
complications after what was supposed to be a routine
hip replacement operation. This news will, I’m sure
sadden many U.K. VW fans and all those who know Rich.
Mrs Tricker was often to be seen accompanying Rich
to VW shows in the U.K.. Our thoughts and sympathy
goes out to Rich and his brother Brian. Get out into the
garage again Rich...the European VW scene would be
poorer without you.
The Holiday period is now a distant memory and I'm
sure most of you had a good time socialising at parties,
meeting old friends and possibly making a few new
ones. I'm considered a bit of a social "animal"…a talker, some say too much of a talker. Before we set off
for a party Jacqui warns me not to go on about
"Vintage VWs" or "Web Sites". I don't know what
gives her the idea that's what I'm likely to talk about
but I have to say it's a good "out" if you get stuck with
a stranger in a conversation about stamp collecting
(sorry not my favourite subject).
This is why I get excited as I view the calendar at the
beginning of the year. I realise there all those lovely
VW meeting to go to in the U.K. and mainland Europe
where I can talk myself hoarse without the feeling of
guilt or that I've embarrassed Jacqui again.
The U.K. scene gets going quite early with a large
indoor swapmeet at Stafford. "Dub Freeze" takes
place this year on Sunday 20th February (
http://www.dubfreeze.co.uk ), I'll be there looking for
a few bits and pieces for our Brazilian Kombi.
The first big U.K. show happens in April with "The
Volksworld Show" (http://www.volksworld.com) at
Sandown Park, South London. 2005 is the 11th year of
this show and is one of the best-established
Volkswagen shows in the world. It doesn't attract the
general owner participation of the large outdoor shows
but it is certainly the place to view some of the best
show cars in Europe.
The one show here in Europe that has suddenly "taken
off" is the vintage show at Hessisch Oldendorf near
Hanover in Northern Germany. It takes place on 24-26
June and is fast gaining the reputation as an annual
Bad Camberg. If you live outside Europe and you are
considering coming to Europe for a show, Hessisch is
THE Vintage Show of the Year. We'll be there with
our Kombi so come up and have a beer with us…how
could you resist :+))
If you would like more details about the show have a
look at their website: http://www.uralt-kaefer.de/
Of course Le Bug Show at Spa, Belgium later in the
year will yet again draw a big crowd. I can personally
recommend this as a great all round show for the VW
enthusiast, Jacqui and I attended in 2004 and had a
great time.
Hope to see many of you in the coming season.
John.
VW JUDSON REGISTER NEWSLETTER
FEBRUARY 2005
4
Website Search
F
or those who have not visited the website recently
you'll not know about the new search facility to be
found on the Judson Register main entry pages.
You'll now find a "Google" search panel at the
Sad Loss
N
o matter what marque car we own we all have our
favourite car magazines. The VW camp worldwide
has just a few well-established titles to support our
vintage hobby. The daddy of
them all is "Hot VWs" which
first hit the newsstands
back in 1967 and is still
going strong. Second on the
list is the other U.S. magazine "VW Trends" which was
established
in
1976.
I'm sure most of our U.S.
members with a VW interest will already know that
"VW Trends" has now
ceased to be. After 28
years and 268 issues the
publishing giant Primedia
has found that "Trends" was
just not contributing enough
to it's $1.3 billion annual
turnover and the last issue is on the newsstands now.
I know there are many Judson Register members who
have had their cars featured in the magazine over the
top of all the main sections listed on the top links bar.
This should speed up your search for that elusive piece
of Judson information hiding somewhere on the site.
years (me included) and will be sad to realize a cornerstone of the VW hobby will no longer be there.
The magazine has had its critics from
time to time but 28 years of publication shows that it got a lot of it right
too. Personally I enjoyed the mix of
stock and Cal-look, Beetle and
Bus…put up with the occasional
spelling and grammatical errors (as I
hope you do with my efforts) and
always found the staff only too willing
to support our backwater of VW
interest when we had a new product
to shout about.
For those of you who complain that
their favourite magazine has been
taken over by advertising, put up with
it! It's probably the only financial
reason why it still appears on the
newsstand.
So ask yourself, when you last bought
a subscription for your favourite magazine? Find its
website and go and do it now…no matter how well you
imagine your magazine is doing, it needs your regular
support to survive and flourish.
Judson Performance
T
here are as many factors governing performance
of a supercharged engine as the normally aspirated…a few more really as we are running an extra
pump.The obvious ones are ignition timing, carburetion,
vane and rotor condition, and lubrication but an oft
overlooked and important factor is a leak in the induction system.
I had an email recently from a long time "Register"
member Phil Barrow of New Jersey, reminding me how
simple it is to conduct your own test.
Phil wrote:
“Hey just fixed my first manifold leak. Noticed that
power was down and when I sprayed some soapy water
on the manifold/head-mating surface, presto, it looked
like a bubble machine, (at least I knew the Judson was
pumping air!!). Well, I installed a new gasket and back
in action...
Tell the folks to go heavy on the detergent when mixing up the soap solution 1/3 detergent: 2/3's water (It sticks to the manifold better and makes a better
bubble). You can also use the bubbles that you buy for
kids (the ones with the wands). If you have kids, you
always have a bottle or two on hand anyway.”
…there it is, if you don't have a Judson Gauge to monitor vacuum and boost pressure and you're puzzled why
your Judson's under performing, Phil's test is a good
start point.
FEBRUARY 2005
Decals & Badges
I
don't know how many of you know, (but I think it's
worth repeating) the Judson Research and Mfg Co.
never made a metal "Supercharged by Judson" badge.
That fact unfortunately, hasn't got in the way of a few
opportunists who thought because of the growing
interest of Judson Superchargers the market needed
the invention of a "period" badge.
Around 1999 there suddenly appeared, out of nowhere,
a steady supply of NOS and used "Supercharged by
Judson" badges. They were about 6 inches long, roughcast in pewter with red and black enamel infill. If you
were a dealer you could order them as NOS, aged 10
years or 25 years…it was a good seller and cost only
pennies to produce out of a back street workshop in
Brussels. Someone on The Samba.com is selling them
for $75 each…probably $74 more than they cost to
make.
O.K. a case of buyer beware, especially on Ebay where
they began to appear described as "period", "genuine"
or "NOS". They made good money too…$135 for one
"NOS" example to a buyer in Japan. It was at this
point I thought we'd better get involved…to try to
stop the profiteering by people with no real interest in
Judsons, at the expense of the enthusiast who did. But
what was the best way to do this? The only way we
could think of was to produce our own superior quality
badge in a size that wouldn't sit up and smack you in
the face (see picture: below).
We went through all the options on size. I thought the
6-inch badge was just too big, definitely too big for
the dash panel, too big for the VW Fan shroud and it
looked awful on my Bug's decklid. I'd originally bought
two of these large badges in 1999 but ended up sticking one on the rear apron, the closed decklid covering
it most of the time, the other sat on a shelf in my
garage.
Now I know a lot of you will have one of these large
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VW JUDSON REGISTER NEWSLETTER
badges, I've no problem with that and nor should
you…providing you didn't pay through the nose for
one. My thoughts on the size of the badges are
just my personal opinion…we decided on a 9cm
badge for ours, (just under 4 inches) and I still
think we got it right.
Incidentally about a year ago another 6-inch metal
badge appeared on Ebay…from a British source
this time. It didn't carry any exaggerated claims
about authenticity but the seller did let us know he
was lucky enough to have just one of these "very rare"
items for sale. Strangely enough when that "very rare"
item sold he was lucky enough to find he had another
equally rare "Supercharged by Judson" badge. He must
have stumbled upon a secret hoard of these "very
rare" items because he doesn't seem to be running
short of them at the moment. In the description of
this badge he goes on to describe it as a quality item
and "not a crappy sticker". Well that comment made
me see red on two counts. The first being the stickers
offered on our website by member Bob Dorr are by no
means sub-standard. They're printed on high quality
Mylar, are fade resistant and just about everyone who
owns a Judson Supercharger has one of Bob' stickers
on their car…so if he insults Bob he insults us all.
Secondly if you're a Judson purist you'll see Bob's
sticker as the nearest you can get to the original
Judson water transfer decal…there are a lot of
Judson owners out there who wouldn't have anything
else.
Oh yeah…back to our badge.
It has sold well…the first batch of 100 sold in just
over a year so we ordered another 50. These have sold
at a lot slower pace and now that we're left with just
a few, the decision on whether to order another batch
has to be made. At first I thought we'd not bother
with another order until a member emailed me to ask
about badges. I told him the story of the miraculous
appearance of the NOS badges and my intention not to
produce any more authorised badges after the current
stock sold out.
VW JUDSON REGISTER NEWSLETTER
"Surely, he said, if you leave the pirates with the market to themselves, 10 years down the line people will
believe the 6 inch badge is a genuine Judson article."
Hmmm, he has a point…looks like we'll be ordering
another batch of badges...correction, we have ordered
another batch of 50.
6
FEBRUARY 2005
When we had our Judson badges manufactured I was
tempted to have a batch of them made as gold and
black but decided against it. They would have looked
great but nobody would have thought them the correct
colour and I doubt if I'd have sold any.
Today all water transfer decals are very rare…it's
easy to understand why; they can only be used once.
So what did you get when you opened your new box of
Judson goodies?
You got a single water transfer decal for the inside of
the rear window. I have the red and black version you
can see pictured but they came in quite a few other
coloured versions too.
Judson collector Rinie Roodbeen has a gold and black
Judson decal and if you look closely at the pictures of
the Judson kit shown in the "Wheels" road test, to be
found in the website "Archive", although the article is
in black and white, I think the decal shown is also a
gold and black one .
If you bought the SP Judson or one of the other
Judson models that came with an intake manifold as
part of the kit they had a "Supercharged by Judson"
plaque attached with two small rivets. These weren't
intended as body badges although you occasionally see
modern reproductions of them appear on Ebay as
embroidered patches.
So if you can't find an original water transfer decal,
I'd recommend one of Bob Dorr's stickers. If you
want a high quality body badge then you can't do any
better than buy one of our officially approved
"Supercharged by Judson" badges…but I would say
that wouldn't I.
You'll find both on our "Buy & Sell" page.
FAQ Update
M
ost of you will have seen our FAQs page at some
time. It's a quick reference for the beginner to
pick up some useful information but the answers to
some of the questions need updating from time to
time.
Answer: This is one that has changed over the life of
the FAQs page. Yes you can fit a VW Type 2 to these
engines but they need a larger Crankshaft Pulley to
overdrive them to give you the required boost pressure.
Backtrack 6 or 7 years and I was in the same position
as most beginners, scrabbling around on the Internet
looking for scraps of information about this mysterious Supercharger.
So why have some of the answers changed over the
last 4 years?
A while ago I added a note warning that we don't recommend fitting to the 1600 dual port engine. It doesn't mean that it can't be done but the warning is in
response to the experience of others. It seems that
when I hear stories of things going wrong with a
Judson application it usually involves overdriving the
blower for a larger engine.
Experience…yes I know a lot more than I did when
"The Register" started but as the membership grows
so does the collective knowledge, all drawn from personal experiences.
With over 500 members we're bound to have the
whole range of Judson experience and very probably
there's not a thing that hasn't been tried already
amongst those 500.
Question: Can I fit a Judson Supercharger to my
1500/1600cc VW engine?
What you have to ensure if you are going to increase
the speed of the Judson rotor and vanes is that
they're in top-notch condition. The increased speed of
the rotor will create more heat through compression
and friction, before long (if the rotor or other components are worn) you can run into the dreaded "Thermal
Runaway".
This means the blower produces heat faster than it
can be dissipated and the temperature of the blower
just keeps going up and up. In this situation a blower
FEBRUARY 2005
surface temperature of 500 degrees F is not unusual.
This doesn't just apply to the larger VW applications,
it can happen on them all. You often hear the same
complaints from Spridget owners when they overdrive
the SP Judson for the later 1275cc "A Series" engine.
It's not all doom and gloom for those who want to
overdrive. You will probably not be surprised to hear
that George Folchi has no such problems when overdriving his 1275cc Austin Healey Sprite.
George told me:
"My overheating problems have gone, a combination of
an aluminum radiator and limiting full advance in my
distributor. I've been able to run hard in hot summer
weather, and I am overdriving at about 1;1.5 crank to
blower, about the same as the VW. I get 5 PSI max
boost, which is the limit with this size pump, but performance is very good, smooth, and flexible. I have no
"flat spots", and I am very satisfied."
Again if you're like George and are happily overdriving
your Judson on a larger engine let us know. It's easy
to get a distorted view when the only people who email
are those with a problem.
7
VW JUDSON REGISTER NEWSLETTER
you want?
At the moment I'm following up a suggestion from
German member Claus Missing who has been successfully using Stihl Chainsaw 2 stroke oil for a number of
years. This mineral 2-stroke oil is available in 1-litre
bottles and certainly costs a lot less than Marvel Oil
and as an added bonus it's red in colour too. You'll find
a stockist near you, just go to www.stihl.com and click
on your countries' flag. Most 2-stroke oils are slightly
heavier than the 10W Marvel but it seems to run well
in the Marvel Oiler and from the experience of others
2-stroke oil seems to work very well.
If you have a "magic potion" as a Marvel substitute, let
us know. I'll post your ideas in the next newsletter.
Question: I'm having trouble finding Marvel Mystery
Oil where I live, is there alternative oil I can use?
Answer: Yes, it's the same for me too, here in the U.K.
You can find Marvel here but it's hellishly expensive. I
was lucky when I bought my Beetle with the Judson
already fitted. I inherited a large drum of Marvel
Mystery Oil (see picture) but I'm afraid it's getting
pretty low now.
Over the last few years I've tried a few alternatives
mostly following up suggestions from The Register
Forum. The best option I think is 2-stroke motor oil.
The reason is it's formulated to lubricate, cool and to
be burnt in the combustion process …what more could
“The Marvel Oil Company” was founded in 1923 and for over 75 years produced an upper cylinder lubricant and
oilers for the automotive industry. The Oilers were produced as an add-on accessory. No auto manufacturer
would admit it but most cars of the 20s, 30s and 40s had inefficient lubrication systems and a supplimentary oiler
was seen by most enthusiasts as a sensible addition.
The Judson Res. & Mfg Co saw the “Marvel Inverse Oiler” as an ideal lubricating system for their superchargers.
Positioning the oiler within the engine compartment was a simple matter...high...low, it didn’t matter as the oil was
sucked into the combustion chambers by vacuum.
It’s interesting to note that the instructions issued with your new Judson Supercharger when you bought it never
referred to “Marvel Oil” by name. The instructions said simply, use a 10W chlorinated oil.
The “The Marvel Oil Company” was taken over in 1998 by “Turtle Wax” and although they no longer produce the
Oilers they continue to produce “Marvel Mystery Oil.
If you live in the U.S. you might like to look at Shipstore.com for your Marvel Oil Supplies:
http://www.shipstore.com/ss/html/MAV/MAV015.html
I must admit to being envious of our U.S. members when I visited their Marvel Oil page to check out their price to
replace my rapidy deminishing 5 Gallon drum. The price is $86.99 which is probably less than one quarter of the
U.K. price but I’m not sure shipping a drum of oil to the U.K.is acceptable using a normal postal service.
VW JUDSON REGISTER NEWSLETTER
8
FEBRUARY 2005
I
f you are a Beetle owner with
your Judson sat snugly beneath its
decklid maybe you're thinking, What's
the problem…take a deep breath and cut.
Yeah that's easy for you to say but if you were the
owner of a pristine VW Bus, Karmann Ghia, or Karmann
Kabriolet I think you'd have to think long and hard
before getting out the tin snips.
What I'm talking about of course is that not all
Judson Supercharger applications sit comfortably in
the engine bay. The VW Bus needs a four inch section
to be removed from the cross-beam that sits above
the carburettor, (see below) the Karmann Ghia a section of the air vents in the deck lid and the Karmann
Convertable a section of the rain drip-pan inside the
deck lid.
cutting the body what other options are left to you?
All the VW problems spring from the Judson Air
Cleaner… the blower sits on top of the inlet manifold,
the carb sits on top of the blower and the air cleaner
sits on top of everything. Even with the Beetle it's a
tight squeeze and the original Judson installation
instructions give a few hints on how to make more
room for the air cleaner.
It states: "Additional hood clearance can be obtained
if necessary on all models by loosening the transmission mounting bolts and raising up the engine in the
front with a jack thus lowering the engine and carburettor in rear".
The decision for most of these applications is cut
and use the stock Judson Aircleaner or make a
replacement that won't require the tin snips.
Way back when the Judson and all the accessories
were readily available off the shelf and the vehicles
that were to receive these body modifications were
virtually new, most people didn't give it an second
thought.
30…40…or even 50 years down the line these everyday
vehicles are now our rare and precious babies, as many
say "cutting's not an option". So if you've ruled out
As you can see from our front cover and at the top
of the page, Split Bus owner Andy Bye decided to
leave off the aircleaner and make a layered gauze
insert that sits inside the carburettor throat.
The picture shows just how tight a fit it is with the
40hp Judson. The 36hp engine allows a few millimeters more clearance but because the 40hp Judson
requires the use of a carb spacer between the blower inlet and the carb, even without the air cleaner it
can still be a "no go".
Andy's solution has been to have a reduced thickness
spacer made by a local machine shop. This gives that
vital extra few millimeters to "shoe-horn" in the
Judson without making the cuts.
Andy says if you'd like one of these spacers he has a
few left. Email me and I'll pass on your request.
FEBRUARY 2005
VW JUDSON REGISTER NEWSLETTER
9
pan needs to be modified or removed to accomodate
the Judson blower pulley. The Judson instructions
recommend cutting away part of the offending pan but
Register member and Judson ‘Vert owner Larry
Schemel had a different idea when it came to fitting
his VW Type II Judson.
“I thought about trying to cut out one side of the pan
to leave part of it but I didn’t think this was really
possible. I decided to remove the drip pan completely...if you’re careful you can remove it and if necessary
you can get a guy who is handy with a torch to replace
it should you want to sell the car or the Judson later”
You'll see here member Kyle Kimball's beautiful
restoration of his 57 low light Karmann Ghia. As I've
said...many owners have reservations on the necessary
surgery so I asked Kyle if he found the decision to fit
the Judson Scoop to a pristine decklid difficult.
"No not at all. I had set out on the KG restoration with
a Vintage Speed theme in mind. Having settled on a
Judson set-up the decision was just a matter ofcourse.
If it was to be a period correct Vintage Speed
restoration then the Ghia had to have the correct
Judson Air Scoop..liking the way the Air Scoop looks
on the decklid was also a help.
With an early KG the cutting of the decklid is simplified by the fact that finding a replacement decklid is
not too difficult. The Ghia lid remained
unaltered from it's introduction in 1955 until the first
change in 1962 so there are plenty out there in the
salvage yards and the online classifieds."
Manifold.
Another method has been suggested to give more
room. That is to take a little heightout of the stock
VW intake manifold. This on the face of it looks a simple solution until you realise, if you do modify the manifold upright you're in danger of fouling the distributor, generator and Judson throttle linkage. I don't
think it's possible to remove enough from the manifold
to accommodate the Judson aircleaner in a VW Bus but
it is possible there would be sufficient room made for
the Karmann Ghia and the Karmann Convertible.
About a year ago a 36hp intake manifold appeared on
Ebay. It was described as a "Judson 36hp Manifold",
made for use with Karmann Ghia and Karmann
Convertible. As you can see from the picture (above) it
was well made but it turned out not to be an official
Judson accessory.
Now to the Karmann Convertable...of course as the
Convertable boasts the same engine bay configuration
as the Beetle Sedan and you'd think it wouldn't pose
any greater problem. Ah but then you're forgetting
the rain drip pan attached to the inside of the decklid.
Because the “Vert” doesn't have the louvred panel
below the rear window to provide the airflow for the
aircooled engine the air louvres are cut into the decklid itself. To weather proof the engine bay a drip pan
is fitted to channel away any water incursion. This drip
I bid on the item but unfortunately I didn't win but
the seller was kind enough to take pictures and measurements so we could have a replica made at a later
date. That information is still here waiting to be used.
If you are a fabricator with good welding skills and
you'd like to have a go at modifying a stock manifold
let me know and I'll let you have the details.
It’s not the kind of accessory you will make a lot of
money from as the market is pretty small but as we’re
on the subject of repros if anyone has a Judson Ghia
Scoop that they would be prepare to lend so we can
make an accurate copy let me know.
VW JUDSON REGISTER NEWSLETTER
Would You Dare?
O
ne of our members from Finland, Jukka Koistinen
sent me some pictures of his 1300cc Beetle just
after Christmas. It looks like a fine restoration and
the Judson installation was also interesting on a couple
of counts.
1. Jukka has fitted a twin-belted VW Type 1 Judson to
the 1300 engine and
2. It has no Oiler.
The fitting of the
early VW Judson to
the later 1300 VW
engine is indeed interesting but it's the
absence of a Marvel
Oiler that I'd like to
talk about here.
The installation was
completed in the latter part of 2004 and
of course in Finland
the onset of winter
from October onwards means there's not much chance
to put a lot of mileage on the new Judson…100kms have
been driven to be precise.
So how has Jukka got around the absence of an Oiler?
His solution is one I've occasionally heard discussed
but never implemented…add Marvel Oil to the fuel at
every fill-up. There is nothing revolutionary about the
theory, 2 stroke engines have used the technique for
many years so if it works for them, why not for the
Judson.
I've often heard it said that on a warm summer's day
a Judson Supercharger would run about 50 miles without lubrication before meltdown. I don't know if that
is true and I don't know anyone who has had the misfortune to try it…intentionally or otherwise.
Jukka adds Marvel Mystery Oil to the fuel tank at a
Mystery Judson?
A
few months ago I received an email with pictures
of a mystery. Register member Bob Carlock from
Orofino, Idaho had found this roots type blower and
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FEBRUARY 2005
ratio of 1:100 (1%), which according to my "ball park
figure" calculations is slightly higher than drip-feeding
it in the normal manner. The question is how effective
is this way of lubricating the Judson vanes. I know
upper-cylinder lubricants are added to the fuel mixture but they aren't intended to be the sole lubricant
in the engine…more a cleansing agent. The route from
the fuel tank to the supercharger chamber is a long
way and it's difficult to know what happens to the
Marvel/fuel mixture
on the way… how much
is absorbed by the
fuel…
are
there
changes in the lubrication properties of the
Marvel Oil?
I know Judson "Guru"
George Folchi has an
opinion on this alternative method of lubrication, George told
me;
"There is a risk of
wearing the vanes out prematurely. Mixing oil with the
fuel will not deliver oil in the same ratio of RPM to
load, as the oiler will. It will average out the same, but
only time will tell. If it was this simple, I am sure the
Judson Co. would not have incurred the extra cost of
the oiler in each kit. It is true that the vanes are in
contact with the housing at all times, but the oiler is in
direct relationship to vacuum, and fuel with mixed oil
consumption can vary greatly with driving style, low or
high RPM cruising, and hill climbing. Anyone trying this
may want to carry a spare set of vanes as a precaution!"
That's another opinion, if you have anything to say on
this subject or have tried it yourself we'd like to hear
from you.
Sometimes things that you think won't work do…and
the other way round so let us know what you think.
from the name stamped on the casing it was a
Judson.
Well as usual I got excited thinking this was a very
early Judson Supercharger I'd never seen or heard
about. In matters like these I get pictures and send
them out to our Judson restorers and to Haddon
Judson in Conshohocken.
My pipe dream of finding an early Judson blower was
quickly dashed as it was identified as an American
Pepco Supercharger. Mystery over? Well not
quite…why was it stamped with the Judson name?
FEBRUARY 2005
VW JUDSON REGISTER NEWSLETTER
11
Judson Rotors & Vanes
I
don’t know how many times you have heard
this but I know I have written this so
many times in past newsletters and in emails
to people looking to buy a Judson
Supercharger...”don’t buy until you have seen
inside the blower casing.”
It seems to be common sense but because
people see them rarely, some get carried
away with the feeling that if they don’t buy
“this one” they won’t have another chance
for a long time.
If you look at the pictures above you'll see two examples of Judson Rotors; one is new and the other was
bought on the Internet. One boosts at 5psi and the
other at 3psi...the wear on the worn rotor is typical,
about average for a Judson bought “blind”. It’s still
useable but it will never boost at the elusive 5psi.
When buying a used Judson Supercharger one of the
most often used and also one of the most useless
phrases offered is "rotor spins freely". Well I can tell
you, whether the blower has done 300 or 300000 miles
you'll usually find the rotor spins freely. If the seller
has never opened the casing he is in no position to pass
an opinion on its condition and if you’ve not seen
inside...fear the worst.
The profile of
the rotor slots
along with the
condition of the
vanes are the
two main factors that govern
whether you'll
be getting your
money's worth
out of your
Judson.
You'll find if you
buy from our recommended restorers a lot of the
guesswork is taken out of the equation. They've
already filtered out the worn rotors...don't get me
wrong...normally a certain amount of wear has to be
accepted when buying a used Judson...they will still
boost but the truth is, the less wear the greater the
boost. The pictures you see here are ample reason to
illustrate why you should heed this advice.
The picture of the recut rotor shown here (left) is
proof if you need it that although Judsons look bullitproof they can also suffer failures. Don't get paranoid
about it though...if you check out the slots on this one
you'll find they've been butchered by someone who
thought they had a good idea. Obviously this one had
flared slots...a common remedy was to machine out the
slots to recreate the parallell profile and fit oversize
thickness vanes. Machine away any of the rotor and
you are inevitably weakening it...machine away too
much and this is the result...a fatal failure will quickly
follow.
The new rotor, pictured below shown against the neglected rotor makes an obvious contrast. A vane in a
crisply cut rotor slot will respond well to the working
specifications of the supercharger. The neglected
rotor has an accumulation of gum and dirt inhibiting
the correct action of the vanes. This dirt is a combination of carbon and Aluminium dust from the wearing
VW JUDSON REGISTER NEWSLETTER
of the slots, usually as a result of years of poor lubrication.
If you'd like to know what a newly cut or NOS rotor
slot should measure have a look at the pictures at the
foot of the previous page. With a new vane in place the
slot won't quite accept a 0.07mm feeler gauge…a
0.05mm gauge will. This close tolerance will hold the
vane in place…it won't drop from the slot by gravity
but can be removed smoothly with two fingers.
The worn rotor shown, on the other hand will accept a
0.90mm feeler gauge up to an inch into the slot illustrating the extent of flaring.This wear of the four
slots also contributes to the imbalance of the rotor.
Just before completeing this article Italian member
Peppe emailed some pictures he’d taken of a purchase
from our “Buy & Sell” page. He’d bought a NOS 40hp
VW Judson from Montevideo, Uruguay...you can still
find them but you have to be quick.
Just to illustrate
that you can’t just
bolt on even a NOS
unit without opening it up, this is
what he found.
“There was only a
little surface rust
on the internal
bore of the housing
which polished out.
I had to change one
bearing as it was
rusted inside. The
seals were perfect, soft and still greased from the
manufacturer. The rotor is beautiful, so are the vanes.
I discovered a printing in one side of rotor, a sequence
of number, probably used for balancing purposes, for
recognising angles.”
12
FEBRUARY 2005
surface at very high speeds lends the individual molecules an abrasive property. This phenomenon is nothing
new, it’s well known in marine engineering, jet engine
technology ...anything that spins a blade at high speed
through any medium and goes by the name of "cavitation". If you own an outboard motor you’ll be familiar
with the scoring on the propellor blades, it’s much the
same thing. Luckily the Judson’s performance isn’t
affected by this type of wear, the edges aren’t
touched as you’ll see in the picture. This vane comes
from my Judson, it’s 5 years old and there are no chips
or dings where it matters.
So after 50 plus years why are we still using phenolic
linen vanes? It’s a question I have asked as I know
there are other more modern plastics that wear better and Judson users who have experimented with
them.
The answer is “expansion rates”. Phenolic linen vanes
have a low expansion rate...you can cut them to fit
snugly in a Judson knowing that although they will
expand, it’s not enough to jam them up inside the blower casing when the going gets hot. The harder wearing
materials expand more and this means you have to cut
them shorter giving in theory less boost at lower temperatures.
Another fact you might not have considered if you are
thinking of using one of these newer materials is that
in a piece of machinery where two materials rub
together one will be harder wearing than the other. In
the case of the Judson of course it’s the vane that
wears more quickly. That’s as it should be...the vanes
are cheap and easily replaced...the rotors are not.
I’m not saying the modern vane materials are harder
wearing than Aluminum but they will upset the balance
and cause the rotor to wear more quickly.
Vanes
V
anes always show signs of wear surprisingly
quickly. If you have a look at the picture of
the vane (right) you’ll see some quite deep scoring on it’s face where it slides in and out of the
rotor. This may appear surprising as there are no
rough edges that could cause this scoring and even
more surprising is that this wear pattern will begin to
occur in the first few weeks of use.
So what causes this scoring? The answer is “Airstream
Etching”. No...don’t bother looking it up, it’s the nearest I can get as a non-technician to describe what is
happening.
The rushing of the air/fuel/oil mixture over the vane
There you have the cause of many of the accusations
levelled against Judson Superchargers …noisy, tendency to overheat and don't live up to the expected horse
power gains. You could say that about any piece of
worn machinery.
FEBRUARY 2005
13
VW JUDSON REGISTER NEWSLETTER
Another Judson Magneto?
T
his is a picture
of an item sold
on
Ebay
just
before Christmas.
I knew the seller
as I'd seen him
offering this item
at a swapmeet a
couple of years
before. It looks
like a genuine
Judson article…it
has the Judson
name on it but
apart from this
one I don't know
anyone else who
owns one.
I emailed the seller to see if he could any more details
to the item, he replied:
Membership
D
ecember 2004 saw us top the 500 mark…5 years
500 members…that's ahhh, let me see 100 a year,
even I can work that out. The interest doesn't seem to
be diminishing…in fact registration seems to be speeding up.
Out of that 500 we have 37 different nationalities so
you see the appeal of this odd piece of '50s hardware
is universal. I can see the attraction…out of all the
pieces of Vintage Speed hardware the Judson is still
the most affordable, available and backed up by a few
highly skilled restorers and re-manufacturers.
Amongst those 500 we have some who started their
relationship with Judsons over half a lifetime ago and
I hope we can get some of them to share their stories
and experiences in this Newsletter in the issues to
come. Yet another appeal to you, if you have a Judson
Story to tell to get tapping on the computer and rooting through your old photographs. There are people out
there who would love to hear about your '50s. '60s.
'70s experiences and if you have Sprite or Volvo or
"Yes, this thing has me completely foxed! It is clearly
designed for use on a VW motor but the drive shaft is
longer and has a groove for a Woodruff key. I think
that it is a universal fit and that the separate bottom
piece is the 'adaptor' used to install it on a VW motor.
I got it from Tom Lieb, who owns Scat Enterprises,
some years ago. He didn't know anything about it
either!"
As usual I sent out pictures to the usual experts to
get the definitive answer. Haddon Judson came back
quickly with the story of this "Judson" Magneto:
"This isn't a Judson item. We at one time. under contract, modified approximately 5,000 Vertex Magnetos
with Judson electronics. I still do this at present. The
Vertex Scintilla Mags had a metallic label stating that
the magneto was a modified Vertex magneto by
Judson."
Renault don't think people won't be interested…we're
all car freaks.
I'm awaiting the arrival of an old magazine I won on
Ebay a couple of weeks ago…the attraction? An article
on a Judson Supercharger fitted to a Norton
Motorcycle. It begs the question; is there room on a
motorcycle to fit one. Check out the "Whats New"
page in the next few days…I'll scan and upload it as
soon as it arrives.
To conclude this edition I’ll just make my customary
appeal for you to visit the “Membership” section of the
website and click on the email button that allows me to
add your details to the Membership Listing.
Despite having a far flung membership it’s amazing
how often we sign up members who live just a few miles
from each other. It’s satisfying to do things for yourself but it can also be satisfying to get together with
someone who needs your help and encouragement.
VW JUDSON REGISTER NEWSLETTER
Classifieds
14
FEBRUARY 2005
For Sale:
Ultra Rare Accessory-Bag of NOS Brazilian
Fuska Candy.
This is your chance to own a complete bag of NOS Fuska
Fruit Candy.
The bag has only been opened to illustrate contents.
Each item has been individually wrapped in a full colour
illustrated VW Fusca (Beetle) cover.
A large number of empty wrappers are also available on request. Will sell as complete bag
or split. Bag $250 or $5 per individual piece.
Email John: info@vwjudsonregister.org.uk
Wanted
Complete Judson kit for 36hp engine, any condition. Interested in individual parts as well. Will pay $$$ or
trade NOS parts, extra 36hp engines and more!!! Call at 905-706-0729 or Email.
Email Brad-Ontario,Canada:bschmidt@repco.com
Wanted
Hi! Looking to find one original Magnesium "BRM" without cracks to complete my set. Also need 4 Caps (not
Flat4 repros).
Email Benoit-Quebec,Canada:ben65@videotron.ca
For Sale
Complete 36 horsepower Judson kit. Everything rebuilt or NOS, even a NOS Judson coil... badges everything
ready for that show car. $2500
Email Richard- California,USA:Karmann55@aol.com
Wanted
I am restoring a VW11 Judson Supercharger. I have the base part of a 36hp Judson aircleaner. I would like
to exchange it for a 40hp one or a complete 40hp aircleaner if you have one. I have found here in Italy a
suitable replacement for the glass reservoir but it is not exactly the same. If you are interested I have photos of it.
Email Peppe-Italy:peppebug@hotpop.com
Wanted
Looking for a complete VW II 40HP Judson Supercharger Kit...Have cash...Want nice stuff ...Please send pictures.
Email Chris-Ferndale WA USA:cszolomayer@matrixservice.com
Wanted
Stock Distributor to fit a 1964 1200cc engine... 34hp(UK). Vacuum advance type in full working order please.
Fair price paid! Thanks.
Email Ian - Guildford UK:anything@shmik.vispa.com
For Sale
Brazilian car magazines (including VWs). Please state you interest...I have a lot for sale, from the 1960’s up to
the present day.
Email Samuel - Brazil:sammartins82@yahoo.com.br