I have a friend racing a vintage Datsun roadster with the Japanese SU's. He
has a high speed lean miss which he believes is fuel related, although line
pressure is adequate. I seem to recall discussions about high speed airflow
across the bridge and rounding the piston on the inlet side to reduce the
turbulence. I know this has come up with TR's: I have a friend with an Ambro
that experienced the same problem for years and could never figure it out
with jetting or ignition. Finally he tried airflow as a last resort and it
smoothed right out.
What's been the collective response to this issue? Is it turbulent airflow
across the bridge reducing the siphon effect, or is it something else? I have
a set of nicely rounded pistons and domes ready to use from my racing days,
but I never wound my motor that high for it to be a problem.
Steve & Janet Hedke
Great Race #45, 1957 Triumph TR3
britpac@aol.com
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