Kas, et. al.
RE: Jack Drews quest for carb improvement.
Although I have a set of SU's on the shelf, I have elected to continue to run
the older style Strombergs. For whatever reason, I never encountered the same
problem to the extent that Jack did, I have a little bit of it.
I am running the SU needles per your instruction in the little black book by
wrapping shim stock aroung the needle shaft. All modifications to the carbs
are quite modest, mainly getting rid of the sharp edges. I run with a fuel
regulator and the engine is 87 mm with about 10.5:1 CR. Head flows nicely.
What's two or three things that I can do to improve the Stroms with out going
bonkers about it. Recommend a needle with these specs?
Any opinions between the two carbs. I feel I have had great success and
reliability with these carbs...and many folks kind of turn their collective
noses up at them.
Regards,
Joe
<< Interesting problem that I have encountered before. The Strombergs have a
diaphrame so the piston is ruled by an accurate depression while the S.U.'s
have a static clearance that can vary. Its not likly BUT the clearance may
be too large on the SU's between piston and dashpot. More than likly though
the needle and seat are too small for the flow demand. I have almost always
needed to increase the flow of the needle and seat by drilling out slightly
(sorry don't remember those numbers). I also drilled the main jets as you
have suggested. I have used a #38 drill .101", and a #37 drill which is
.104". The #37 more than does the job so I would use the#38 first and see
if there is any improvment. Do check the float levels though as this puppy
just might be not be able to flow the dmeand of the engine. >>
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