Setting up Zenith Stromberg carbs on a 3.9 RV8
Posted: Tue Sep 15, 2009 5:07 pm
Hi all just wondering what adjustments need to be made to run zenith stromberg carbs from a 3.5 on to a 3.9?
Cheers
James
Cheers
James
Hello James,
I'll start by saying that I have never used Zenith Stromberg carburettors, but I have and continue to use SU carburettors.
I transferred the SU carbs off my 3.5 to my 4.6, changing the throttle butterflies which originally had poppet valves for ones without.
Adjusted the floats so that the bowls held more fuel, and fitted richer needles which were custom modified on a rolling road.
I also fitted significantly larger K & N air filters.
I would expect at the very least that you would need richer needles. The idle mixture is essentially the same, but off idle the taper allows more fuel through for a given piston lift.
Ron.