This is the best article I've seen on dizzy advance logic. Don't know author but it's on a site by JeffP, one of the serious Z-heads at zcar.com.

http://www.angelfire.com/extreme/280zxt/page5.html

Let me know what you think. I've been suffering with a fairly annoying PING in my 260Z daily driver, and I'm almost motivated enough to start studying up this article and putting it to use.

I'm thinking of pulling the pulley on the 260 and filing (or machining) notches at 5 degree intervals from TDC to 45 degrees BTDC. This would allow reading the advance characteristics with an ordinary timing light. (Last I checked fancy timer w/ advance indicator function was $400 from Snap-on!)

Actually, I should probably do this on the 145, while it's up on blocks and radiator is out. That'd be a good time to install steel cam gear also. I suspect B20B is gonna have a hard time w/ PING what with 91 Octane super being all that is available anymore here in rainy North Calif.

Later,
Al