How many of you guys use the Vaccume advance on your distributor to carb? My engine is capable of doing so, but the privious owner capped them off? Would I see any difference with it hooked up, or should I leave it alone?

How many of you guys use the Vaccume advance on your distributor to carb? My engine is capable of doing so, but the privious owner capped them off? Would I see any difference with it hooked up, or should I leave it alone?

IMHO it will hurt performance...

I don't really even know why they call it a vacuum "advance"...A marine engine, especially a jet makes almost no vacuum at all at wide open throttle or even when at a 3500 RPM cruise. The way a vacuum advance works on a car is when the vehicle is cruising down the freeway the engine has a fairly high vacuum signal, this signal then advances the timing improving fuel economy and generating a small amount more HP, once the throttle is increased the vacuum signal drops and retards the timing a small amount to prevent detonation.

Leave it disconnected or better yet find an eliminator kit and set the timing for high RPM, not low...

GT

On every gm style hei I have i never use it but I do change the springs on the mechanical advance to a lighter spring. When using the lighter springs I drop the timing to 12* at idle opposed to 15* with the firmer springs.

Fat fingered from the phone-  Corey