[chevelle67]

All right another question for you guys, since you did very well on the last one. I got a 327 SBC and I have the base timing set for
4 degrees. My question is 2 part what should the advanced timing be? Can I run the engine without vacuum advance? I was told that I should be around 34 advance without the vacuum advance and install the vacuum and if it goes up to 45-50 degrees don't run it. What do you guys think

[Tmod]

Really hard to suggest something when no info is provided on cam, compression ratio, fuel octane and what the intended use is.

These all play a important roll in the choice of the optimum advance curve and total timing.

[chevelle67]

I guess that info would help a little. The engine is 10:1 compression the cam is a 230 duration with a 480 lift and it is running on pump gas 92 octane

[Frisco]

Originally posted by chevelle67
I guess that info would help a little. The engine is 10:1 compression the cam is a 230 duration with a 480 lift and it is running on pump gas 92 octane

A good starting point would be 10-12 degrees initial and 34-36 Total mechanical (initial plus mechanical) all in around 2500-3000 RPM. Set this with the vacuum advance disconnected and plugged. Re-connect the vacuum advance after you have set the timing.

Don't worry about what the timing shows with the vacuum advance hooked back up as it will not function at WOT. You may wish to limit how much advance the vacuum pot gives you by using an adjustable one. Try it first to see.

If you get pinging when in high gear going up a slight hill at a moderate speed; back off the timing 2 degrees and re-test until no pinging occurs.

As to running the engine without the vacuum advance; Yes you can but for street application I would not. The vacuum advance is designed to improve the overall driveability and gas mileage. For a race only application it is not neccesary because you would be at WOT and there is '0' vacuum at that time and therefore the vacuum advance will not function.