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A few years back, via a fellow forum member, i was able to acquire a Judson Supercharger designed for a TR3 but which should fit a TR4/4A. It was in well-used/damaged condition with the casting broken and the bearing at one end seized.

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For the last few years its sat in my parts bin whilst i sought a skilled welder to fix the casting...luckily I recently discovered a Aluminium TIG welding specialist here who concentrates on repair of engine parts....so that has triggered me to get moving and restore the Judson before fitting it to my car.

image.thumb.png.8979505f1e6690ef667505096d5a9c55.png

 

I dont know if this is accident damage (there's no other dents or deformation) or if it just shook itself to bits when the bearing failed...there was a lot of slop in the shaft.

 

The welder charged 160 Ringgit (27 quid) to fix the casting & re-face the manifold flange. 

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The rotor seems in OK condition. George Folchi, the US Judson Guru (http://www.judsonguru.com/), has supplied me a new set of vanes. The slightly weird Garlock Klozure oil seals I have sourced from the US, they are inch size:

Garlock oil seal MILL-RIGHT 63X0213
SIZE:ID 0.875" x OD 1.375" x 0.313" Thk - 2pc

Garlock oil seal MILL-RIGHT 63X0113
SIZE:ID 0.688" x OD 1.375" x 0.313" Thk 1pc

The bearings are standard size and readily available, but since the seized bearing has damaged the shaft, i am gonna fit an undersized bearing on that end after having the shaft turned-down to the right size:

image.png.afb7a86247f7db2a1e610c2046f237da.png That groove in the shaft is caused by the siezed bearing.

I have a rebuild kit for the Holley 1904 carburetor, I have a Marvel Mystery Oiler of suitable dimensions...we are almost ready.

To fit the judson to a TR4A its necessary to revert to the TR3/4 style cast iron exhaust manifold, simply because of mechanical clearance issues with the 4A style manifold. Luckily, another forum member came to rescue & sold me a good TR3 manifold I can use.

My Judson came with some historic documentation which i will share below...

 

 

Edited by ctc77965o
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My Judson seems to have been first purchased by a Chris Bauer of Pompton Lakes, New Jersey

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Maybe this wasn't first purchase, as this correspondence is from 1967 and these chargers are most common on late 50's vehicles, but still the Judson Company provides a series of information leaflets to Chris:

image.png.deedec7470439bc8c6cb3b0e40f0cf09.png

 

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It seems that timing was an issue.. this TR3 document advises cutting the centrifugal advance weights to delay the advance curve:

image.thumb.png.4cdff11fa6f1f5ee29e69772ef292f59.png

Then some updates for the TR4 where the weight-cutting isn't mentioned:

image.thumb.png.bdb3a02f6ab9295e8cd6a6d43a32d4af.png

And then a service bulletin which recommends locking the centrifugal advance and setting the base timing at 18 deg BTDC (!):

image.png.b77e63cc15063935e512439edad6de1a.png

This last bulletin makes some more sense in terms of limiting boost advance, i have some limited experience with a BMW 02 turbo, and that also struggles to find a suitable ignition timing using a standard distributor.

 

 

Edited by ctc77965o
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great posts.. I have the "modern" Moss Supercharger setup and it is fun. Interesting comments about timing, I resorted to an Aldon Amerthyst device which allows digital control including boost retart. Still not straight forward to get it to work!

Tim

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Dave, great to hear your project is live !  Set it up really rich under boost, ideally with a UEGO. A normal lean cruise mixture can be used along with a vac advance fed by the throttle edge take-off. Use the highest RON fuel you can find for initial running untli you are certain it not detonating under boost. Worst rpm for detonation is peak torque region ca 3000-3500 rpm. Can be difficult to hear. Low RON fuels will need less advance. Beware if your cylinder head has been skimmed.

  It will drive as if you had bolted on a couple of extra cylinders !

Peter

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This sounds like a lot of fun Dave and £27.00 a bit more than reasonable for that work....... Can you imagine back to the 1950’s if anyone in Judsons would know someone in Malaysia would be getting as much joy out of it all in the 2020’s?

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Eldred Norman was a demon  racer of a supercharged TR2, the first inported into S Australia. He engineered his ownn Judson-type superchargers mainly for Holdens. Theres a long thread here; http://www.fbekholden.com/forum/viewtopic.php?f=25&t=18810&start=75

Peter

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image.thumb.png.8b1fac7d5da64d21132d0ab0b5c2436b.png

Judson-A_Few_Facts_On_Supercharging.pdf

 

A nice 4-page marketing intro from Judson

TESTIMONIALS

Here is what the world’s leading auto magazines say about the Judson Supercharger:

  • Das Auto (Germany) “The Judson Supercharger has greatly impressed us . . . it truly allows a new experience in motoring.”
  • Road & Track “The car is completely transformed with absolutely no objectionable features.”
  • Auto Visie (Holland) “The difference in performance between the supercharged and unsupercharged car is greater than one would believe possible.”
  • Motorsport “After putting the car through its paces and comparing notes on its present vs. past performance, there can be no doubt about the value of supercharging.”
  • Sports Cars Illustrated “This type is quite efficient at all engine speeds and also has die added advantage of being very compact. It produces a positive boost at all rpm’s and is not subject to mechanical failure.”


A few of the many unsolicited statements from owners:

  • “I would never have believed that the addition of anything could improve the performance of my car the way your supercharger has.”
  • “I never knew what I was missing until I installed one of your superchargers on my Volkswagen.”
  • "The increase in acceleration is positively amazing. I would never have believed it possible.”
  • “It's just like adding two more cylinders.”
  • “It’s like getting a new car.”
  • “Not only is the improvement in performance amazing but so is the smoothness of the engine and the absolute silence of the supercharger.”

A supercharger gives you more than just improved performance ... it gives you a thrilling new experience in motoring pleasure.
 

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With a touch of CastrolR in the oiler it will even smell supercharged !

Those comments are true, in my experience with a diy installation.

Peter

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Agree with Peter. The torque on mine comes in a lovely whoosh.  

Tim

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Eldred Norman's book summarising supercharging is useful: http://www.fefcholden.org.au/techinfo/supercharge/index.html

Some of his exploits, including  12psi-blown TR2: https://09befcf3-bc09-4ab4-98cc-6a92e5d43a3a.filesusr.com/ugd/1c88d8_d50ec6b88bbc4d328dc8a492eac03511.pdf

When racing TR2 ran on methanol, for road use on petrol he fitted a decompression head gasket. It towed a trailer to race meetings with two drums of methanol.

Peter

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Hello ,

I had the pleasure of testing a MG A on the dynamometer twice.
Before conversion and after conversion to compressor.
We couldn't believe our eyes .......... over 30% more torque.

Stay alert
Ralf

 

Judson Kompressor.JPG

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How will you drive the SC?

Did you get the replacement water pump pulley with the belt grooves?

Someone had a Judson on their TR4 and that was driven from a double grooved crank pulley and it was a great disappointment.  The problem was the speed the SC was being rotated at and it was too slow to give any appreciable boost, so I modified the thing for the owner with a pulley from a Volvo 240.  It flew then!  .....Until a bearing seized.  Lack of the Marvel Oiler in the system.

Peter W

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strangly I have a Judson "on the shelf" and it too had damaged ali manifold fixings... I have had it welded up (sadly not at your prices!) and now it needs dressing.

Not plucked up the courage yet to try and fit it B)

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36 minutes ago, Nigel C said:

strangly I have a Judson "on the shelf" and it too had damaged ali manifold fixings... I have had it welded up (sadly not at your prices!) and now it needs dressing.

Not plucked up the courage yet to try and fit it B)

Hopefully this thread will give a boost to your confidence :ph34r:

Peter

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3 hours ago, BlueTR3A-5EKT said:

How will you drive the SC?

Did you get the replacement water pump pulley with the belt grooves?

Someone had a Judson on their TR4 and that was driven from a double grooved crank pulley and it was a great disappointment.  The problem was the speed the SC was being rotated at and it was too slow to give any appreciable boost, so I modified the thing for the owner with a pulley from a Volvo 240.  It flew then!  .....Until a bearing seized.  Lack of the Marvel Oiler in the system.

Peter W

PolyV belts are ideal. - as used on the MGA Ralf posted.

Peter

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16 minutes ago, Z320 said:

Which carburetor do you use with the supercharger?

Is one H/HS6 enough? A HS8 is pretty expensive.

Ciao, Marco

Yes, one HS6 (1.75 inch) is fine according to Allard. Slide 48 is from his book:  https://supertrarged.files.wordpress.com/2015/08/supercharging-trs-for-the-road-iwe-shorter-for-wordpress.ppt

Peter

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2 hours ago, Z320 said:

Which carburetor do you use with the supercharger?

Is one H/HS6 enough? A HS8 is pretty expensive.

Ciao, Marco

The 'standard' carb on the Judson is a Holley 1904, a single barrel downdraught.

http://morrisgarages.ch/holley-carburettor/

Its hard to believe it will flow enough...seems it will throttle the 'charger even when wide-open

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Interesting that the judsen used a holley for carburation. My modern moss conversion uses a twin barrel holley. 

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12 hours ago, ctc77965o said:

The 'standard' carb on the Judson is a Holley 1904, a single barrel downdraught.

http://morrisgarages.ch/holley-carburettor/

Its hard to believe it will flow enough...seems it will throttle the 'charger even when wide-open

That has been used to limit boost  at higher rpm, in a simple way. to allow more boost at lower rom. Ideal for road use. However most carbs will supply a supercharger far more mixture than in normally aspirated applications.

Peter

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