Originally Posted by
jerry clayton
Your supercharged Corvette had almost nothing similar to this rod--the vett was electronic fuel injected into the port just as the intake valve was open--
this engine has 2 carbs on top of a 6:71 and the overly rich fuel jetting is adding fuel to all the air that the blower is drawing thru the carbs and at slow speeds with little exhaust backpressure and scavaging by the headers, a good amount will be blown thru the cylinder on the camshaft overlap portion of the valve timing. At idle, time(as in tic,tic,toc) is pretty relavant to this as at high rpm its insignificant) 600 rpm is 10x as much time as 6000rpm) and the gas rich mixture will flow thru the 2 open valves into the exhaust and stink up your garage.
Now your carb system may be totally off as for jetting and powervalve sizes/settings and maybe if calibrated better might solve your fuel smell, but it remains that a supercharged engine can and will pump air/fuel thru the cylinder on the valve overlap portion of the exhaust/intake stroke--