OK Guys:
Last time I wrote, i said i was still experimenting with the timing, & here's what i have done: (I'm a blacksmith, not a tuner, so i need help!)
I'm running an HEI with 18 degrees initial, 30 degrees with the vacuum connected, which gives a pretty good idle. I modified the weights for a total centrifugal of 10 degrees at 2800 RPM. But here's the Biggie: I connected the vacuum advance to the boost side of the manifold.
Remember, the bypass valve is being used, and boost is limited to 7 PSI with the pulley. At 2000 RPM in 5th on a level road it still shows 8 to 10 inches of vacuum on the boost side. This gives about 35 degrees total timing, including centrifugal. When i push on it, the boost drops out 10 degrees of vacuum advance, giving about 25 degrees total, up to 28 degrees at RPM above 2800.
This seems to be working great.
Has anybody else out there tried this?
Will the vacuum diaphragm stand 7 PSI of boost for long before it ruptures?
I still have never heard any sign of detonation. Will it be obvious, like those V8 thingies pinging? I know long term pinging is destructive to an engine, but will this cause damage instantly at 7 PSI boost? I know this is long & wordy & I hope it all makes sense.
This old fool looks forward to hearing your tips & advice.
Thanks alot!
Pappy
