Hey just out of curiosity what RPM do you guys set initial timing at?

I'm tuning my 350 (stock bottom end), 224/230 @.050 .502"/.510" cam 110 LSA cam, HEI distributor with mechanical advance. Anybody have some good base line numbers for initial and mechanical advance timing?

 

First you need to get the timing set to where the car will turn on and idle somewhat reasonable.

From there you can adjust the car a bit to get the rpms to about where you want them THEN you set your timing at wherever you want it to be at.

Once that is done you can mess with the carb do get everything dialed in.\

Now as far as what numbers to shoot for is completely dependent on the engine. I good/safe 'base' is about 8 degrees. But on my 305 this was way too low and I was running hot. My Camaro seems happiest at 16 degrees initial.

You also want your max timing (34-36) at around 3000 rpm.

 

what RPM is the initial timing set at?
At 650 RPM I am at about 4 degrees, I only did it to get it to idle and prevent it from stalling when I give it throttle.

 

Base timing is set at an idle with no advance in the distributor. With a mechanical distributor such as a large cap HEI, once you start increasing the rpm, the weights start to move outward to give it mechanical advance. If the distributor has a vacuum advance canister on it, the canister should be unplugged and the vacuum line capped off while checking the timing.

Base timing is best based off the cam duration. Your 224/230 will probably work best with 12-15* of base timing. Knowing what the best total timing however is trial and error. The above example is a good ballpark number to start with. For best performance, total timing should be all in by 3000 rpm.

 

To set the base timing in a mechanically-controlled dist, the RPM just has to be low enough for the weights to fully retract. Which of course varies from one individual dist to another.

I agree roughly with Alky's suggestion; that's a reasonable guess for a starting point for tuning, for your setup. Give the engine whatever it wants, and don't get all hung up on what the "numbers" turn out to be.

 

thanks guys. I've done this before but never really cared about peak performance. I'll get it dialed in today hopefully.

 

Buy the MSD advance kit 8428 and put the light springs in. This will give you more timing at idle which will smooth it out and also give you more torque down low.
Then set your total timing at 3000 rpm to 34-36.