I have a 9.3-9.5 to 1 compression ratio on the current 350 motor. My current, (and best) recipe/method for MY engine is as follows. Mods can add it to the knowlege base, or make a sticky of it, if they think its good enough. This is a poor mans method. It should take you about an hour. A few guys have asked questions about this recently...and it got me thinking to write up my method.
1. Get a timing light that works...nothing fancy, no dial back, just a cheap light.
2. Purchase cheap Mr. Gasket distributor kit like this:
http://www.summitracing.com/parts/MSD-8428/ and throw the weights in the garbage. They are crap and hang up on each other.
3. Start car, loosen distributor hold down clamp, and hook up timing light. Remove vacuum advance line from distributor and plug. Start car. Set timing to 20 deg at idle.
4. Experiment with different springs and see at what RPM the timing will not advance at any further.... This involves revving, taking note of where the timing is at different RPMs, and noting the RPM it stops going any farther. (it helps to have a friend inside the car watching the tac, calling out RPMS as you operate the timing gun if your gun doesn't display RPMs)
5. Get the right springs installed where the timing will NOT advance any further by about 2600-3000 RPMs. (I am using one light, and one medium spring)
6. Have a friend rev the car from inside to whatever RPM the timing stopped advancing at in the previous step (2600-3000 RPMs) and set the timing at 38 degrees at that RPM.
7. Let the car idle down and check timing at idle. It should ideally be between 18-23 degrees. If the car starts ok hot, it's probably fine at that timing at idle.
8. Go for a test drive. Listen for pinging/detonation, and see how the car responds. If you hear noise/vibration, or the car doesn't respond well, go back and take 2 degrees out of the total mechanical timing (bringing it to 36 degrees at 2600-3k RPMs) Try again. It should feel GOOD and HAPPY!
9. If at cruising speeds, you notice detonation, you may want to limit the vacuum advance. You can do this with a limiting plate that usually comes in the re-curve kit....or make your own. I like it limited to about 12 degrees. You can check the vacuum advance at any rpm by hooking the vacuum line back up to the distributor and seeing what it jumps to.
10. Tighten distributor, re-hook vacuum line, and have a wonderful time telling people how you re-curved your distributor.
Now before some wiener says "But, but, but..... my timing tab doesn't go that high!" I have a solution.
With the motor off. Rotate the engine by hand with a wrench till the timing line on the balancer is at 10 degrees on the tab. Mark a new line on the balancer at 0 degrees according to the tab. Now, when that new line is on 10 degrees on the tab, you are actually at 20 degrees! Get it? You can put as many lines on your stock balancer as you need to. Aftermarket balancers usually come with lines all over them anyways.
Feel free to add or criticize.
Re: Ignition timing advance questions.
