iam2fast4u86

Ok I know there are plenty of posts about timing and I have skimmed through them but would like to see what opinions I can get on my timing. I am still in the break in stages on my Olds 350 and am trying to do some tuning in the process. I have it running pretty good and guess I better get into specs before I ask questions. 71 350 block honed stock bore, stock polished crank, stock rods, clevite bearings, perfect circle rings & pistons, stock heads(re-built), melling oe style oil pump, melling MT4 cam, cloyes timing chain, factory 403 4 bl intake, edelbrock 600 elec choke carb, flowtech headers, accel wires, delco plugs gap at .045 and procomp hei distributor. The idle is rough due to the cam but I believe it could be better. My low end acceleration is a little flat but I have what I believe is a stock highway gear in a g-body so that is to be expected. My problem is that my mid range torq seems like it's holding back. I know my carb needs adjusted(running rich) and have someone who will help me with it but I think some of my issue is attributed to timing. Now I know you guys are going to aske me if the cam is degreed and yes it is. My base timing is set at 15 degrees btc @ 1100 rpm and approx 190-200 degrees temp. At 2500 rpm I have 34 degrees btc and at 4000 rpm I have 36 degrees btc. This seems ok as far as numbers go but I know that there are no "specs" once you start using performance parts-the car will run right where it likes to. I am just wondering if anyone has any input on any of this?

brad75

I hear you. I'm in the same boat with my Comp 268H cam. It seems to run better a little bit more advanced,but "pings" when I stand on it. I am using octane booster,so I don't think it's the gas. I guess I wil try backing the timing down some. ???

Brad

J-(Chicago)

Brad, I have a 455 motor here in my daily driver with a 268h cam.

I run timing at 25 @3000. (with vacuum advance disconnected and plugged while checking it).

svnt442

Stock initial with an HEI is 20°. That is gonna be a BIG starting point.

iam2fast4u86

Wow 20 degrees? That is a whole lot of advance.

svnt442

They cut down on the mechanical advance with the HEI. It was an emmissions thing.