Vacuum advance information and myths

Mattax said
Exactly. I said it was BIG Myth. Case in point.
It's an easy conclusion to come to when just experimenting with switching to the the manifold source using a distributor designed for a retarded initial timing - as many of us have. Its actually a better method than just advancing the initial - which leads to all sorts of problems because of the timing curves.
That's why I invited everyone to go look at the original material themselves.

When using a distributor that doesn't have a curve to compensate for retarded initial, then ported works out better - and especially with a hot cam - its more stable.

So I like to start with a clean slate on an engine and buy the edelbrocck dist. It is adj mech and vacuum. I set the mech to the most responsive, most power I can get. Then I hook up the vacuum to the manifold port and dial in my advance to just below pinging under load.

This gets me the best throttle response and mileage and no hint of overheating. Never had an issue and my **** always runs better then the guys struggling to cool their engines. Cant go on a cruise my car over heats ect.

PV does create heat and burn cleaner. It is less friendly on a street car in my experience. I adj my carb to compensate for the adv drop and have zero bog flop issues.

I'm not sure if I'm disagreeing with you or not. PV is was for emission reasons.