I see that people's base timing varies drastically. I've noticed timing from 8 degrees to 36 degrees locked out. Is there a way to tell how much initial timing is required for an engine? Or is it just learned from experience? Can someone give me an approximation of what initial timing I should run on the engine in my sig? It's going into a 68 chevelle w/ 3.73 rear gears, a 2004r and using 91 octane. (I'm getting the XS282S cam from a friend for a really good deal instead of using the magnum 282S cam smile.gif )

I agree that this is confusing. I have researched this and for a performance application like you are building I would suggest starting at 16-18* initial with the vacume advance plugged.

16-20 seems to be the numbers. I suggest running manifold vacuum for the VA. That will put more initial in once the engine is running.

BTW, I've used the ported vs manifold vacuum chart you posted a few months ago a number of times. Thanks graemlins/thumbsup.gif

Pat,

What chart are we talking about?

Regards,
Gary Anderson

This one (http://www.chevelles.com/cgi-bin/forum/ultimatebb.cgi?ubb=get_topic;f=4;t=020095) smile.gif

Thanks Pat, I'll have to study it when I gat some more time. If you don't mind the "foreign car" slant, this thread has some very good info in it. I can personally vouch for the Echlin vacuum canister, but it fits the points style distributor. If you can cross ref. it to a similar one to fit an HEI that would be money.

http://forums.performanceyears.com/eve/ubb.x?a=tpc&s=7286011111&f=6406082911&m=841101836

Regards,
Gary Anderson

16-20... oh boy... I guess I'll have to recurve my distributor... again :rolleyes:

Thanks for the help guys... and I'm glad you like that chart I found. graemlins/thumbsup.gif