Vacuum Advances

[Don C]

I know from reading threads in our (and other) forum that vacuum advances are not very well understood. I came across the attached article on theory and operation of vacuum advances on the 460Ford site:

http://www.460ford.com/forum/showthread.php?t=117504

It's written by a former GM engineer, so I apologize in advance for all the Chevy stuff. It has part numbers for a lot of GM vacuum advances and I left them in because I know there are several members running HEI distributors. I've been looking for similar part numbers for Fords, but haven't had much luck. The only single advance vacuum control that Standard offers for our cars is VC-31. If I find some, I'll add them to the attached. Ford, too, had a variety of different spec'd vacuum advances. The Crane adjustable may be our best alternative, now.

Timing and Vacuum Advance 101-v1.pdf

 

[Valhallo]

Learning new stuff everytime I get on this forum. Thanks for the post.

 

[will e]

Great read! Thank goodness for the internet (sort of). After working on my own car for over 25 years I finally got the right info on timing advance, how it works and ported vs manifold. That was about 2 years ago and mirrors what this article says.

 

[deepanvi]

Fitted to earlier points and electronic type distributors, vacuum advances form part of RAE's total ignition program.