Yes...
There is no "Judson dizzy" per se...no
such thing as far as I know. You modify
the mechanical curve (usually just "shortening" is all that is required)
to
a reasonable 24-26 degrees (on today's
octanes..26-28 on "yesterday's") and your
basically done. With the originally intended and available leaded
octanes of
the day, the stock BE distributor was just
fine and Judson recommended stock settings in this respect, with a
colder
spark plug.
The more intelligent tuners backed off
the timing a few degrees to prevent
blown head gaskets in time, though,
considering they were going to be
blasting around with thier foot in it most
of the time. Others with the equipment
available just "shortened" the mechanical
curve to give a total of 28 degrees while
utilizing the stock static setting.
The blocking off of the vac. line or
the lack of a vacuum advance came about mainly to prevent pinging when
you backed off to partial throttle after
a run in boost, when cylinder temps were
still high and the engine hadn't "cooled
down" yet. You wouldn't want the added
advance from the vacuum chamber under
these conditions as you reapllied throttle
even out of boost. I would say this would
be even more so on today's unleaded
octanes which will cause higher combustion chamber temps then the
higher octanes of yesterday's leaded
premiums, all else being equal.
Aldon built my "supercharger" dizzy based
on my specific engine spec. and the use
of 93PON unleaded (computers are a
beautiful thing!!:). It's a 43D (no vac.).
Came with a 12 degree "swing" and
recommended static setting of "0" for
a total of 24 degrees at the crank by
4400rpm. It's a WOT curve so advance
rate is pretty slow as compared to the
stock Cooper S curve, which really isn't
suitable for low pressure supercharging
at all, most especially on today's unleaded octane premiums. It's too
"quick" and the
curve is too "long".
As I eventually shelved the Judson idea,
I had to "modify" the Aldon for normally
aspirated operation.
Had to "shorten" the swing to 9 distributor degrees to produce a total
of 18 at the crank. Static timing is 12 BTDC so we're
running a total of 30. Works well in present Cooper S tune with AH2
needles
in the stock SU's.
Cap'n. Bob
'60 :{)
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