LOL...
....Cap'n Bob's Judson set-up was done by
none other than the US Judson guru himself! George Folchi lives just up the
road from me here in CT. The Judson in
question was upgraded for overdriven
operation and a special "wheel" was machined by George himself (2.8") to
provide for the originally intended 6psi
boost curve. Guess what? It worked!!!
Car went like a raped ape using a Cooper
S 40819 dizzy artificially "capped" at 25
degrees max crankshaft advance.
The problems were the following, these on
a stock 1275 running BPR8ES plugs:
only a mix of Citgo 93PON and CAM2 to
provide at least 100RON would allow more
than a couple of runs at one time before
coolant overheating set in. We did better
on 100% CAM2 "purple". This stuff is now
$7.00 per gallon up here! But the 1275
with the blower loved the stuff!!
But....the other problem.....
we ran into belt slippage around the
relatively "tiny" blower pulley.
required for "overdriven" ops. So we
would need a dual belt drive (a la
Shorrocks) or a cogged belt drive to make
this set-up work consistently. Or...a different size crankshaft pulley so as to
use
the standard-sized Judson blower pulley.
George was supposed to develop an alcohol/water delivery system to cool the
combustion chamber so that readily
available 93PON unleaded could be used.
But, he did not follow through on this any
more than he followed up on a different
diameter crank pulley which would allow
for overdriving without having to down-
size the blower pulley, thus preventing a
slippage problem using the existing belt
set-up over a "tiny" blower pulley required
to overdrive the blower to provide the
originally intended 6psi boost curve to the
larger 1275 motor. So I dropped the idea
as "incompatible" with today's unleaded
octanes, belt slippage problem notwithstanding.
George is running a Judson on his current
1293 but he has no idea where the timing
is (most likely retarded to prevent detonation) and must use 100% Sunoco
100GT unleaded ($5.00 per gallon, plus!)
as he happens to have a Sunoco station in
town that carries this. His use of the car is
occasional on cool days (no hot summer
days) and he must stay close to home for
the proper octane fuel to run the application...so local use only...on cool
days!
Without running on 100RON+, the engine
overheats and goes into pre-ignition rather
rapidly as the engine cooling system (never
a strong point with the Spridget in any
event) is easily overtaxed by the "mini-
turbine" induction heating of the Judson
design (the Shorrocks runs cooler as it's
got "clearanced" rather than "interference"
fit blades).
Also....as far as belt slippage goes....
He has not solved the belt problem so as
to consistently be able to run at 6psi, he
is only able to develop 5psi most of the time...belt slips after the first run
or two.
So go Judson at your own risk. This blower
was not made to run on anything larger than a 948 and on the 948 was designed to
run with the initial 8.3-1 motor on premium 100+RON (NOT PON) gasoline,
and with cooler plugs than stock to boot!
George has also abandoned the problematic Holley carb which drove us
all nuts with the proper accelerator pump
setting (though we finally got mine sorted).
George is now using a progressive downdraft Weber. He has not calibrated
the carb for the application. It just runs
rich.
Good luck! :)
Cap'n Bob
Basic Frog
This application is NOT compatible with today's garbage unleaded octanes,
inclusive of the Sunoco 94PON which we
have available here in Stamford, CT.
Your much better off with a mildly tuned
1275 unless your talking a show car or
something you are going to use occasionally on cool days. Anything over
70F and you can expect hot running without either racing gas or a water or
alcohol/water delivery system.
BTDT with the Judson guru, himself! :):)
Cap'n Bob
Basic Frog
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