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Re: Judson Supercharger

To: kramer.allen@comcast.net, spridgets@autox.team.net
Subject: Re: Judson Supercharger
From: "Robert E. Shlafer" <pilotrob@webtv.net>
Date: Tue, 10 Apr 2007 10:49:47 GMT
Allen...

the Spridget-sized Judson is a little short on capacity for the 1275. To get 
the expected 40% increase in torque you NEED
the 6psi boost curve. A 4psi curve is what you come up with using the stock 
Judson
pulley set-up, which is all show (except for
heat) and no go.

Using a 2.8" blower pulley will give you the
6psi boost curve but not for long as the single V-belt quickly begins 
"slipping" around such a sharp curve, treated or not.

(Modifying the crank pulley diameter rather
than a smaller diameter blower pulley would get you by in this respect, though.)

This results in over 7500 blower rpm and the stock Judson blower bearings 
aren't up to the load (for very long, anyway:) and the concurrent adiabatic 
heat rise experienced by increased blower compression sends combustion intake 
air temps soaring,
further decreasing your margin to pre-
ignition/detonation.

(Modification to blower bearings will do, as will a calibrated alcohol/water 
delivery or
injection system. This could be "T-eed" into
the stock oil delivery system or by other means.)

By the time you get through, simply installing a modern Moss blower kit would 
probably be more cost effective I would think. This would also result in a 
minium of
oil entering the combustion chamber which, on today's garbage unleaded octanes 
would be a real plus as well.

Might work OK on a stock 1098 though, where far less overdriving of the Judson 
would be required for the needed 6psi
boost curve.

But hey...most people can't even get the
Judson to perform well and reliably in year 'round temperatures (summer) on a 
948 on today's weaker octanes! So, you've done a good job! :)

Cap'n. Bob      '60 :{)




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