[slider in wa]

converted the engine over to HEI. I rebuilt one and installed the light weight springs,bigger coil, etc. I also added a programable vaccum advance. Lost the paper work too!!! The truck runs just fine, however i do not know how to adjust the vaccum avance. Could one of you fine people maybe, explain how to do this to me? How about a little theory on how it does what it does??
Thanks yawl !!!!!!
Slider in Wa.

[Steve karch]

You need an allen wrench. Insert it into the opening of the vacuum can (where you attach the vacuum line) and turn it. I'm not quite sure which way will advance or retard the timing but if you have a timing light turn it one way and see what happens. The vacuum advance advance the timing under low load high vacuum conditions such as at cruising speed or part throttle. This will increase throttle response and fuel economy. When you nail the throttle you go to high load/low vacuum which will retard the vacuum advance and revert to the mechanical advance. If you have too much vacuum advance the engine will ping. Depending on the engine, you will want 10-15 degrees initial, 32-38 mechanical and 10-15 degrees vacuum advance for a total 45-50 degress timing. These numbers are aproximate but should give you a starting point.

Steve

[slider in wa]

Thanks Steve!!!
Slider in Wa.