Quote:
Originally Posted by rich weyand
To answer some earlier questions. I am running 16-17 base timing. That is, timing without the vacuum advance hooked up and with the idle slowed to about 600 rpm.
The GM HEI adds 20* mechanical advance, so I am running 36-37 degrees total timing.
The AR23 vacuum advance adds another 15* (spec is 7.5*, which is camshaft degrees), to make 51* all in.
51* is what the advance is at cruise, 2500+ rpm, with the throttle plate mostly closed (not accelerating), so the mechanical and vacuum advance are both in.
I have seen 52* given as an absolute maximum for cruise "all in" timing.
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thanks my original setup was very similar to yours, now as I am getting more comfortable with this stuff I am just trying to tune it in a bit more precisely, can you tell me at what RPM your mechanical advance starts ie kicks in please