View Full Version : TR2/3/3A Judson Supercharger in a TR3?

02-07-2010, 11:36 AM
Anyone ever done this or know someone who has? Any links to information on same? I know someone who is going to attempt this upgrade and any info would be appreciated. Cheers Karl

02-07-2010, 11:48 AM
They show up on e-bay once in awhile in different states of completeness. I believe they are centrifugal blowers.

Check out this link on a Judson supercharger "update". (https://www.v8triumph.com/JS.htm)

Personally, I'd go with electronic fuel injection and then install an Eaton Roots type if I decided to go with a blower. I've got an Eaton in my Miata and it gives a solid 40% increase in power with good reliability.

02-07-2010, 11:48 AM
Hi Karl,

I know someone that has one on a 4...does that count?

M. Pied Lourd

02-07-2010, 11:55 AM
Most tr's have too much compression to get along with the increased boost. If you want to build a blower motor,special pistolas should be fitted to drop the ratio down to 8/1.Other wise you will need race gas at 7.50$ a gallon.I did get a set from vanolia 2 years ago it was not too pricey,bout 100 apiece.
I have been dogging Moss Tech people for several years,they no longer return my calls since they are not too hip on fitting the tr with a modern blower.I am frustrated since my best friend Jim D has a blown bugeye sprite that rocks with the quickest of fast rides,getting close to 100hp at the axel.Of course he had the motor purpose built with the reduced compression to make it all work....
MD(mad dog)

02-07-2010, 12:38 PM
The Judson is a vane-type, positive displacement compressor; and doesn't generate a lot of boost. This is a Good Thing, since it's also not very efficient and heats the air a lot more than more efficient designs (like the Eaton/Roots) do, which tends to cause detonation. The Judson also requires that lubricating oil be mixed with the air (only way to lubricate where the vanes rub on the housing), which further aggravates the problem with detonation (oil has a very negative effect on knock resistance). The original installation included a Marvel automatic oiler that mounted on the firewall and dripped oil into the intake at a rate of about 1 qt/800 miles. Contrary to popular opinion, the oiler was NOT supposed to be filled with MMO, but rather SAE 10 motor oil.

On top of that, the original vanes are phenolic impregnated linen and have a tendency to shed tiny bits into the motor as they wear (or fail catastrophically).

I've got one in my collection, though I've not yet gotten around to trying it. Last time I fiddled with it, I couldn't get the silly little 1bbl downdraft carb off the manifold. There is a nut located where you can't get a wrench or a regular socket on it...
(PS, No, it's not for sale.)

There is a mail list on Team.Net for Judson and other superchargers, but traffic has been really light for the past few years. It may be that other members are like me, and got inadvertently unsubscribed without realizing it!

I've got a fair amount of information squirreled away, Karl, in various forms. Email or PM me if you'd like a copy. Unfortunately, a lot of it is pretty poor quality, 3rd or 4th generation copy in some cases.

02-07-2010, 01:02 PM
Does any body know how Moss is coming along on there super charger?

02-07-2010, 01:10 PM
Like I said they are NOT doing much and dont seem likely to.I dont know why,but it must be a perceived lack of marketability.....
MD(mad dog)

02-07-2010, 04:21 PM
Here's a website for Judson with links to parts.


02-07-2010, 04:38 PM
One of the magazines (Hemmings Sports & Exotic, or Classic Motorsports, don't remember which) tested a Judson Supercharger, I think on a Sprite. They did not get the period advertised increase in power, but they did get a considerable bump.

I know that wasn't exactly the question, but if I were thinking of installing one would certainly be curious about the increase in performancee.

02-07-2010, 04:54 PM
Does any body know how Moss is coming along on there super charger? AFAIK the TR6 version is available now (they had one at TRfest but I didn't pay much attention)

And they have effectively no plans to develop one for the other TRs.

Just my perception/WAG; I suspect they are not selling as many of the TR6 version as they had hoped, and whether it's accurate or not, they perceive the TR2-4 market to be even smaller.

Kelvin or Peter, feel free to step in here and tell me I'm wrong ...

02-07-2010, 05:10 PM
Hmmm, didn't I see a TR2-4 mock-up at Triumphest?

02-07-2010, 05:18 PM
Does any body know how Moss is coming along on there super charger? On the Classic Motor Sports web forum, in the Orange Blossem Tour section , there is mention that it will be in the group.

02-07-2010, 05:59 PM
didn't judson also make a magneto?

02-07-2010, 06:18 PM
didn't judson also make a magneto? It was called a "magneto", but was actually an early electronic ignition.

02-07-2010, 06:52 PM
I recall them and they were real popular in the sixties. I lived close to Conshohocken at the time and we would hang out and watch supercharged VW's racing all the time. Ocasionally we would see a TR or MG with a Judson. They went real fast, but only for a short time. :jester:

02-08-2010, 09:57 AM
Thanks for the input and all who responded. Most informative. Karl