Fuzz1957
Well Known Member
With the timing set at 10 dgs with the vacuum advance plugged once you reconnect the vacuum pot hooked to manifold vacuum you should see the timing jump to 18 or 20 dgs. This should give you a nice clean idle. The small block 327s I worked on seemed to like 34 dgs. total all in by 2400/2600 rpm. Advanced timing at idle allows you to get a really good air fuel mixture adjustment which in turn allows you to back off the curb idle adjustment which gets the throttle blades out of the transfer slots of the carb leaning out the mix making for snappy throttle response. It's all good. Best way to set air fuel bleeds is with a vacuum gauge. I used to be the go to guy around here for tuning. Lots of free breakfasts from my buddies. Small block Chevy's especially responded to a good tune up because the engine was so well designed.
Called Pertronix yesterday and talked to technician. He told me to put on one lighter spring and that should get me “all in” by 3000 rpm. Also asked him how many crank degrees the vacuum advance can added. He said 16 degrees. So if I have 12* initial and 16* vacuum advance hooked up = 28* at idle. Haven’t done anything yet changing spring. Did check voltage at positive side of coil with key on = 11.95 or basically 12 volts as it should be.
Fuzz
MAGA