Wierd ignition thing
Thread Starter
Le Mans Master
Joined: Jun 2008
Posts: 5,284
Likes: 235
From: Rockledge FL
Wierd ignition thing
So I finally got back to the States, got some rest, and decided to play with my vette for a few hours today. New crate motor runs awesome but it definitely needs a good tune. Ignition is wierd. Its a HEI with tach drive and has the gold springs from a Mr Gasket recurve kit in it from the last engine. With the vacuum unhooked. I set at 36 degrees at 3K rpms. The new idle timing is 25 degrees without the vacuum hooked up. I hook up the vacuum and it idles at 37. That just seems a little high to me? When it warmed up, there was no hesitation, no sputtering, no bogging, nothing and it would send the tail end sideways from a dead stop so I am not tooooo worried about it but 25 degrees initial timing just seems high.
Tech Contributor
Joined: Aug 1999
Posts: 14,379
Likes: 6,390
From: At my Bar drinking and wrenching in Lafayette Colorado
Your timing is fine. The gold springs are going to allow some centrifugal advance to come in at your idle rpm, so your timing at idle is not a "true" initial timing setting - it has a few degrees of centrifugal in it. That's why setting the timing for total timing and disregarding initial is the right way to time and tune a performance engine. If you really want to see (for whatever reason) what your "true" initial timing is, remove the gold springs and install a set of heavy stock springs. This will pull the distributor back to its base setting and not allow any centrifugal at idle. I'll bet you'll see a setting of about 16 degrees. But this is all irrelevant - just set the total to 36 and disregard the initial when using those springs.
Lars
Lars
Last edited by lars; Aug 8, 2010 at 11:03 PM.
Thread Starter
Le Mans Master
Joined: Jun 2008
Posts: 5,284
Likes: 235
From: Rockledge FL
Thanks Lars, you were helping me out with this while I was home on leave a few months ago but I never got it settled out before I had to go back. I just wasnt ready to bother you yet so I appreciate you jumping in. After you helped me back in May getting the squirter size straightened out once the car has warmed up there is no bogging or hesitation when the pedal goes to the floor. A cold engine and a heavy foot gets some bogging and some black smoke but Im getting this is normal.
