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gator2511 · 05-19-2007, 08:55 AM

The pdf file posted by Billa is very good with one exception. The author states "and, since most vacuum advance control units pull in about 16 degrees of vaccum advance at cruise speed (where the full centrifugal advance will also be deployed), the 36 degree setting will produce 52 degrees of total combined advance at cruise with the vac advance fully deployed."
I don't know about you but I don't have full mechanical advance at cruising speed. I have always set my mechanical advance to be fully deployed at around 3,000 rpms. I would have to be cruising at 100 mph to get to 3,000 rpms and cut in FULL mechanical advance.Maybe I'm not getting something but if your throttle plates are open enough to get 3,000 rpms your manifold vac will be very low. If I'm reading this wrong please educate me.

05-19-2007, 08:55 AM	#44
gator2511 Registered User Join Date: Mar 2005 Location: tampa florida Posts: 776	Re: vacumm advance question The pdf file posted by Billa is very good with one exception. The author states "and, since most vacuum advance control units pull in about 16 degrees of vaccum advance at cruise speed (where the full centrifugal advance will also be deployed), the 36 degree setting will produce 52 degrees of total combined advance at cruise with the vac advance fully deployed." I don't know about you but I don't have full mechanical advance at cruising speed. I have always set my mechanical advance to be fully deployed at around 3,000 rpms. I would have to be cruising at 100 mph to get to 3,000 rpms and cut in FULL mechanical advance.Maybe I'm not getting something but if your throttle plates are open enough to get 3,000 rpms your manifold vac will be very low. If I'm reading this wrong please educate me. Last edited by gator2511; 05-19-2007 at 01:01 PM.