Contact me if you are looking for one of these Judson kits: AUSTIN HEALEY SPRITE;  VW 40 HP; MG-T

We’re an odd bunch – grown men tinkering with obsolete performance items for obsolete engines. Why bother? Because it’s so cool, especially when it all works!

Original Judson supercharger

The Evolution of the Judson Supercharger Guru

In the fall of 1991, a good friend and fellow Sprite enthusiast called me – he saw an ad on the bulletin board at his local A&P for 3 Austin Healey Sprite parts cars, including 2 Judson superchargers. Did I want to go and have a look?

I had never seen one of these in person, but knew of them from an early Haines shop manual that had a reprinted article from the early 60’s. I knew nothing about them, but my curiosity was piqued!

Someone at the time ran an ad in Hemmings, referring to himself as “Doctor Supercharger”. I contacted him, mainly to ask questions, and mentioned that I had made a pulley and vanes for one of my kits. Could I make some pulleys and vanes for him too? Now I was on to something. Little did I know that this was the birth of a hobby that would run over the next 25 years, and result in the restoration of over 300 Judson kits, and contact with over 1000 Judson users worldwide!

I quickly learned that Judson not only made kits for the Sprite, but for about a dozen other makes as well. In 1993, with a few kits under my belt, I had the audacity to run an ad myself in Hemmings (no internet yet), under the name GBF Machine Enterprises (defunct since 1997), offering parts and rebuild services. Doctor Supercharger had disappeared, and nobody else was doing anything with these. And low and behold, people worldwide responded! I started borrowing parts so I could make drawings, and in a few years I could complete just about every part on every kit, including some castings. I unwittingly became the world’s expert.

Judson had ceased production around 1970, so 20+ years had gone by with no support. Many kits went into storage as they were removed from cars. Many were abused, worn out, or cut up and modified to fit other engines, often poorly, including motorcycles and snowmobiles – I’ve seen them all.  A generation had passed, and virtually no one by the 90’s had ever seen one working on a car. They were shrouded in mystery. Some believed they would ruin an engine, some thought they did nothing at all, and some wanted one in a bad way!

I had a total of one conversation with someone at Judson, in 1992. Rumor had it that they were still building kits to special order, and I wanted to know the deal. “Send us $900.00 and the kit you want – we have no paperwork available”. The conversation lasted about 20 seconds. I’m glad I didn’t send any money, as I know someone who did, and had to chase after it for over a year to get it back.

I have never put my name on anything Judson. At some point, someone was referring to me as George Judson, and others the Judson Guru. I never authorized these names, but as the domain name was available, I decided to adopt it. I am George Folchi. I am not an engineer, but an enthusiast with a decent understanding of mechanics, and a decent machinist. I am honest, reliable, and I don’t rip people off or leave them hanging. I have successfully used a Judson on my 1966 1275cc Sprite for 15 years, proving it can be done! I have my reputation at stake.

The now defunct Judson VW Registry website, hosted by good friend John Moxon, did a superb job of covering every aspect of all models Judson, and copies of installation instructions are still to be found on the Samba website. Along with Alejandro Martin (, and Ricardo (Split Parts Unlimited), we dominate the world of Judson!

A Guru is a teacher. People like to know and see how things are done, so the purpose of this site is to show not only finished kits & parts, but some of the machining operations involved. They may not be the smartest ways to do things, but this is how I have been doing it. You don’t become a master by doing 1000 things 10 times, but by doing 10 things 1000 times!  This is a solitary endeavor for me, a hobby, so it would be nice to have some company! Much of it is very tedious. All of it is dirty. All questions are welcome! If I can interest or inspire anyone in the dying art of manual machining, may God bless me for that.

Finally I would like to thank my long suffering wife Marybeth for putting this site together for me, and for tolerating the noises and fumes from the basement, ruined greasy clothes, and metal chips in the carpets, that she has dealt with ever since she has known me. And an eternal thanks to Al, without whose phone call years ago, NONE OF THIS WOULD HAVE EVER HAPPENED!

George machining a part for a Judson supercharger
The Guru at work – accept no imposters!

This site contains photos of some kits that I have restored, with more to be added when available: Mercedes-Benz 190, MG T series, Volvo, VW 36 HP, and VW 40 HP Judson supercharger. Photos of kits on this site are of work done on previous restorations and are not for sale.