350 timing

[bumnog]

Just wondering how to go about selecting spring and weight setup, base and total timing? Also the vacuum port setup? I have tried different setups and can't quite get it right. It seems doggy on the low end.

[SCkaiser67]

Lighter than stock springs will get you out of the hole quicker, 8 deg initial is good to start with. check your total with a good light that you can tune. shouldn't be more than 34 on a decent built motor. Some people advance it at about 4000rpm till it pings then back it off a bit. Problem with getting all the advance you can is overheating. let me know how it works.

[bumnog]

The mods include Trick flow heads, scat crank, Eagle SIR rods, TRW forged pistons 9.73 to 1 comp, port matched Edelbrock EPS intake and 600 carb, 1.6 roller rockers, Crane 4x4 cam. Trick flow said 36 to 38 deg. but it seems to run worse there. My timing light has advance on it but I am starting to wonder about it. With the vac unhooked and about 4500rpm I am at 36 and when I hook up the vac it goes up 15deg. To me I would think that it would knock like a sob. I know alot of guys unhook the vac but have trouble starting.

[Brian Sisson]

You need to have about 36* TOTAL by 2500 rpm. That includes your vacuum, and your mechanical in addition to whatever your initial is. Don't bother with the advance on the light- just hook it all up and then check it. It may sound better timed at about 14* or so when ideling, but that much timing will crack your heads. With a motor built like that it's not gonna sound so smooth on idle and will be tough to get right by ear.

I have a 350 with similar components- only stock big valve heads. I run an Edelbrock 600 on mine and the HEI dizzy. I tried the advance curve kit and found that it gave me crappy results too. It seemed that no matter which springs I stuck on there it didn't give me the power in low-end that my stock springs did and as such I run them now. I have 11* initial (with the vacuum hooked up, but hooked to ported vacuum) and then at 2500 rpm it jumps up to about 34* with all the timing in.

Hope this helps.....and hope that the guys who know more than me pipe up and correct my errors.
-B.