question about timing
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Instructor
Joined: Apr 2008
Posts: 247
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From: Ohio
question about timing
:Ive got an 86' Coupe and I have a question to other forum members. I had a parade on Saturday morning so friday night ,I decided to recheck the basics like timing,base idle,throttle position sensor. As I was checking the timing,I found that it was set at 6*BTDC and the last time i set it,it was set to 8*BTDC( in my opinion it ran better set there).So I reset the timing back to 8*BTDC and the following morning after the parade I decided to take a fast ride home on the backstreets (I wont mention how fast)
It was about an 80 miles round trip and when i rechecked the timing ,it was reset to 6* BTDC again. I never got any backfires or pops thru the intake. My question is: other than a timing chain ,what else would cause this- it runs fine at high speed
any help would be helpful rather than throwing parts at it THANX
by the way-it only has 33,ooo miles on her
It was about an 80 miles round trip and when i rechecked the timing ,it was reset to 6* BTDC again. I never got any backfires or pops thru the intake. My question is: other than a timing chain ,what else would cause this- it runs fine at high speedany help would be helpful rather than throwing parts at it THANX
by the way-it only has 33,ooo miles on her
Last edited by Vetteatlast; Jul 6, 2010 at 05:16 PM.
Race Director
Joined: Jun 1999
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From: Merritt Ils Fl
Melting Slicks
Joined: Feb 2006
Posts: 2,753
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From: backwoods upstate ny
maybe you're slipping ?
the HEI experiences a substantial amount of magnetic drag at the reluctor, dizzy may 'slip' in the 'retard' direction, esp at high engine speed...when spinning an HEI on my Allen Syncrograph distributor machine, extra clamps are required to prevent the dizzy from slowly moving in the machine mount and 'self' retarding (never seen that before with any other type dizzy, even vertex mags)...some aftermkt intake manifolds have 'dual' dizzy hold-down provisions for more clamping...some claim 'tractionizing' the oem clamp by laying it on an anvil and making 'X's or 'dimples' at the contact points with a chisel/hammer is helpful....tightening your oem dizzy clamp bolt may help, try to avoid 'stripping' the threads in the manifold.
