06-05-2018, 11:48 AM
(06-05-2018, 11:04 AM)JonE Wrote: ok, thanks all - will test with present arrangement and then look for a bronze carb to compare things myself. It seems the raw difference is change from 15mm to 17mm choke.
Out of interest, old Motorsport article mentions the Ruby integrated manifold as having a warm up hotspot constriction that can really do with relieving/removing. Does that chime with anyone - is it worth doing for airflow?
When using the standard sidedraught manifold I have been getting busy with the angle grinder for years, cutting through the central connection between the exhaust part and the inlet. With modern volatile petrol it reduces vaporisation problems. I also enlarge the inlet passage in the manifold. I never understood why it is originally smaller than the carburettor bore. Can a venturi be any advantage at that point?
Robert Leigh