Just checked out the timing on my carbed 502 MAGS. Factory setting was at 8 degrees. Check with light and had 28 degrees total at about 4000 rpm. Checked modules and have 20 degree advance modules. Reset timing to 10 degrees and came out to 30 degree total advance and picked up 150 RPM on the top. Question, acoording to Dennis Moore's "Tuning For Performance", he recommends 32-34 total advance. I am a little leary of cranking these up to 12-14 degrees initial. Anyone messed with this enough to give any reliable feedback. Why do the 502 Mags only have a 20 degree module?

Helmwurst;

I ran 36 degrees on my previous 502MAG. My recc would be to keep bumping it 2 degrees at a time until you don't see any more gains. Then back up to your previous setting. You need to check ALL your plugs carefully after each 2 degree bump to be sure you are not detonating. I just ran the MR43T's then with a crane ignition box. My guess is 32-34 will be the ideal point for your set-up...the previous 502 I had was totally re-worked on the top end.

Did you run higher octane fuel to prevent any detonation at those settings? My engines are bone stock ignition and Quad carbs.

Thanks for the feedback!!

I would definately bump the timing up so its at 32-34. Run it at 32 first then try 34. If 34 makes more power, leave it. If its the same, move it back to 32. You should not have any detonation problems with a stock set up at 32-34. Its supposed to run at 32 anyway.

I ran 93 Octane....

32 degrees would mean 12 initial with the 20 degree modules. Any cranking problems in hot weather at 12-14 degrees initial? I will do a little experminting this weekend, but the weather is still pretty mild.

Thanks for your input!!

You will be fine at 12-14 base and will not have any cranking problems. Also you still be able to run 87 octane.