Judson Superchargers & Judson Rotors

[John Moxon]

The condition of the internal rotor is the most important factor when buying a used Judson Supercharger. Worn slots in that rotor mean the unit will be noisy and won’t boost to the required rate. If that’s not bad enough worn rotor slots will also cause overheating through excess friction, a vane will eventually snag and the whole kit and caboodle will grind to an expensive halt. That’s when you’ll set out to find a replacement rotor…forget it.

Unless you have access to a NOS rotor to get a competent engineering shop to copy it at high cost to yourself you might as well junk the kit. If there’s still something salvageable you might get one of the well know Judson restorers to resurrect what’s left of it.

That was then…now, this week there’s another solution.

I’m pleased to say Ricardo Deisernia aka “splitpartsunlimited” is now having a high quality Judson Rotor reproduced. You’ll find it in the classifieds: http://www.thesamba.com/vw/classifieds/detail.php?id=561380

I know this sounds and reads like an advert and it’s true I’m bringing your attention to it but I make nothing from this nor do I want anything. I have to say I do want Ricardo to be successful with this repro, it’s not hard to understand why. If Ricardo doesn’t recover his cost and make a little on top, then he and people like him will no longer be in the hobby, taking the risk to remanufacture previously unobtainable parts and we'll all be poorer for that.

If you have a Judson that rattles, you have a worn rotor but now you have a solution. It’s not cheap but it is high quality so go and check it out and consign that “characteristic Judson rattle” to history.

BTW Ricardo is also remanufacturing the impossible to find classic ‘50s/early ‘60s Marvel Oiler Bottle.
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John.
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[Snort]

[John Moxon]

[Dave]

I was lucky; the Judson I rebuilt for Hot VWs Magazine had virtually no wear on the rotor, but still, when I re-assembled it, you could hear a slight "clacking" from inside the blower when it was spinning. I've heard worse, much worse, and as soon as you revved the engine the sound pretty much went away.
I think one of the main things is getting the "end float" or end play, between the rotor and the front and back plates right. As well, when pressing in new bearings, realise that those plates are old, and they are aluminum. Take your time, go slow, and get them in straight.
If you have all the right parts, hey aren't hard to rebuild. They are actually quite a simple affair, and WILL provide extra power, with no decrease in reliability, IMHO.
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[DMNCLNR]

I feel like i just sat through an infomercial. On a serious note, I will be rebuilding my judson soon, and will buy the new rotor wether it needs it or not, just to be safe. Although they appear to be a bit pricey, I think in the end they will be worth it. I have bought from libreriajenny before, and he is an excellent seller. Hopefully a pricebreak will come soon
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To his their own PBJ
Pl@y@ #1

[John Moxon]

[DMNCLNR]

[splitjunkie]

[billmetric]

Awesome, I sold a worn out housing by itself a few years ago for $100 , wish i had kept it, I have had about 5 Judsons and I have to say they were all pretty far gone, finally the spool is available, I had one unit that had huge waves in the cast iron part also, I suppose there was enough left to bore it out but I got rid of that one cheap as well, I just broke another oiler bottle a few weeks ago, I have broken 3 of those darn antique pickle bottles, will have to be more careful with them after seeing the new price! , was there ever a smaller bottle or was that the only size available?
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There is an idea of a Billmetric; some kind of abstraction. But there is no real me: only an entity, something illusory. And though I can hide my cold gaze, and you can shake my hand and feel flesh gripping yours and maybe you can even sense our lifestyles are probably comparable... I simply am not there...

[DMNCLNR]

[henry roberts]

just re-asking the question on what the clearance of the blade to blade slot on a new rotor/blade combo is?

thanks.

[John Moxon]

[avus]

.5mm seems like a lot--maybe .05mm??

[John Moxon]

[henry roberts]

thanks john. that is a lot more than i was expecting.

edit. it is a smidge less than i was expecting.

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I know it's been sometime someone posted here...but it got me wondering...OK here's what's on my mind and let's debate or help each other understand more ...OK I notice how the judson rotors wear out and can cause alot of noise..but what if we were to change the rotor to steel or a cast iron I know what why it would be heavy..but I see it like this since the fiber blades are sliding up and down on the aluminum a steel version would last longer ...it would be like using aluminum pulley vs a steel or cast iron pulley cast iron pulley will out last aluminum pulley by alot ... so wouldnt that be the same Logic with the aluminum rotor of the judson ...with a steel rotor version would need be drilled to lighten it up .... or cast iron version....

[steven wardlaw]

Just wanted to share some info on the replacement rotors. The rotor in my Judson was worn so bad when that it sounded like it had marbles inside. The old rotors were not made from a material that was very wear resistant. The aluminum was a cast material that was very porous. The replacement I bought for mine was made from 7071 aluminum and then hard anodize coated. I have machine parts over the years that were coated with hard anodize and I can tell you that with this coating you may never have to replace the part again. I have over 6500 miles on mine since the rebuild and during a tune up this past October I thought I would pull the Judosn down to see how it was doing and it didn't have any noticeable wear. My Judson is still cranking out 6 pounds of boost.