I'm looking for some direction on how to set my timing advance correctly on my Chevy 350ci w/ th350 tranny. I'm looking for better response & more power for street application. I've got factory Hei distributor, Moroso 8mm Blue Max wires, Holley 750cfm double pumper, Weiand 3000 series manifold, I'm not sure about the cam - I haven't gotten to that part of my build-up yet.

I've also got Flowtech Afterburner headers, dual 2-1/2 inch exhaust - no cats, dual Flowmaster Super40's, and an H-pipe installed on my mild beast.

Any guidance would be greatly appreciated.

well if the cam is like stock  i run like 9 to 10 at idle  with a intake/carb/headers/3inch dual exaust  and it rips so till you get a big cam probaly keep timing under 10  

There isn't really a lot to be done until you have the new cam installed. Timing really consists of several interrelated but separate components. The overall performance of an engine has a great dependency upon total advance and the rate with which it's put in.  Timing is more dependent upon compression ratio and combustion chamber configuration, vehicle weight, type of exhaust, the presence of a blower or nitrous, and total gearing than the type of distributor, secondary wiring, size of carburetor, or type of intake manifold.

Timing really consists of several interrelated but separate components. The overall performance of an engine has a great dependency upon total advance and the rate with which it's applied. But this is specifically variable based upon total vehicle component selection as mentioned above.

Total advance is a mix of static or base lead and the amount of variable advance. Beyond a few degrees (2-3) of flexibility, any extra static lead must be removed from the variable advance or the engine will have too much total advance and it will start to surge, power will fall off, and the propensity toward destructive detonation will increase.

Open combustion chambers especially when combined with a full dish piston are quite lazy. They could use more spark lead but unfortunately the lack of mechanically induced turbulence and late burn flame front quench makes these things quite susceptible to detonation. That's a nice thing about fast burn heads like the Vortec, the burn time is significantly reduced without resorting to excessive timing lead and the tendency toward detonation is well damped with a prominent quench surface.

So until this engine is completely configured it’s not really effective to get too carried away with timing changes, since the effort will only have to be repeated for every-other change done to the engine or vehicle.

Bogie

Thanks fo the info! Really appreciate your insight on this. I guess I'll wait till I get my Cam in before tweaking my timing. I was considering a Comp Cam 268 series for this application. What are your thoughts and recommendations on this, or an alternate choice of cams ? I've heard that proper cam selection is something akin to practicing Vodoo from some folks. You don't find out you screwed up until after you screwd the pooch.

Is it true you can mess up a cam in storage by keeping laying on it's side ? I saw this in a recent performance auto show. They said that a cam should be stored by hanging it vertically from a rope ? It sounds a bit exagerated to me, but then I'm not an expert.

I was looking at an article in Chevy HP on simple power gains on the cheap. That's where I got the timing advance idea. What are your thought on carb spacers toward the same goal ?  - cheap power gains, until I can afford all the mods I'm planning for the future.

My ultimate dream is to build up a gnarly 383 stroker engine for my 'red beast'. I'd love to do it all myself as opposed to having a crate engine drooped at my door. Where's the reward in that ? I love to do things on my own, and getting my hands dirty.

I appreciate any guidance you could provide on these questions.