bbeep71
Well-Known Member
Does anyone have the specs for the vacuum advance canister for this MSD 8388 distr(ready to run 273-360). Looking for hg to start advance and what is full advance spec deg/hg when all in?
MSD 8388 distr.
- Thread starter bbeep71
- Start date
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All depends on the engine. That is why the canisters are adjustable. Or lets hope yours is. Are you hooking to spark port vacuum? A vacuum pump can help to find out what you need. Or you can look on the arm of the canister. There should be a number there. Double it and that is what you will get in total vacuum advance on the crank. Not uncommon to see 20 to 22 degrees of vacuum advance. The key is to make sure it does not come in too soon. You do not want vacuum advance in load conditions. So if on cruise and you press the throttle down a tad and you hear a little ping you are getting vacuum a bit too soon. Just take a 5/64 inch allen wrench and stick through the hole in the canister. It should engage and to back vacuum off, just turn a half turn to a turn counterclockwise. This will move the range of begin and full on vacuum advance to a higher vacuum starting point. Make sure you tune the engine first without vacuum. A vacuum guage is best to do this. It would be helpful to know what initial advance and what total mechanical advance you are running as well. Most of the small block folk inticate that 34 to 36 total is the goal.
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