Hello I have a sbc 355 engine with a edelbrock 600 cfm avs carb, performer rpm 70cc heads, performer manifold, performer rpm cam and a mechanical distributor. I set the timing at the recommended setting which is 14 degreese advanced and it ran like garbage. It backfired and had no power so I retarded it to 8 degrees, still ran bad. Finally I moved it up to 41 initial degreese and the problem is almost gone. Does anyone know what the problem could be? 41 degrees is crazy that cant be right, but It runs great.

I'm thinking your plug wires are all one hole off on the cap.

Did you time it with the vac addvance disconected, and pluged? Sounds like with those numbers it is hooked up?

The RPM cam is big enough to need lots of initial. I'd suggest a vacuum advance distributor with a B28 canister (which fully deploys @ 8") hooked to manifold vacuum. That'll give you an additional 16º at idle that your starter won't have to fight. If you actually have 41º initial now (and your advance isn't locked out), I'd expect holes in some pistons if you drove it that way. Keep in mind that initial timing specs only apply to an idling engine. They're useful when the distributor's advance curve is known but useless otherwise. If the enigne is expected to go beyond idle, total advance is much more important.

I would verify my TDC mark

Kx69

Did you ever figure out the problem? I'm having close to the same thing but I'm only up to 26 initial with V/A disconnected at idle. You have basically the same set up as me. 16 to 18 runs like crap, advance to 26 and hold on. Holes in pistons don't sound like a good thing though. What is a (vacuum advance distributor with a B28 canister) can someone provide a link?

Thanks Bob

Kx69

Did you ever figure out the problem? I'm having close to the same thing but I'm only up to 26 initial with V/A disconnected at idle. You have basically the same set up as me. 16 to 18 runs like crap, advance to 26 and hold on. Holes in pistons don't sound like a good thing though. What is a (vacuum advance distributor with a B28 canister) can someone provide a link?

Thanks Bob

Try this, tons of info http://www.chevelles.com/forums/showthread.php?t=189195