Harmonic balancer test
Thread Starter
Drifting
Joined: Dec 2012
Posts: 1,504
Likes: 73
From: Georgetown TX
Harmonic balancer test
I'm still chasing down a miss at idle. Without going through the whole list of things I have done, I can assure you I have done all the normal things and adjustments
I am down to egr issue, balancer issue, or internal leaking valve. Is there a way to determine if my balancer has slipped so that my timing adjustment is not correct. I have read several messages on this forum that this fixed the very same idle miss I have
1989 stock L98 with auto trans, 50,000 miles
I am down to egr issue, balancer issue, or internal leaking valve. Is there a way to determine if my balancer has slipped so that my timing adjustment is not correct. I have read several messages on this forum that this fixed the very same idle miss I have
1989 stock L98 with auto trans, 50,000 miles
Thread Starter
Drifting
Joined: Dec 2012
Posts: 1,504
Likes: 73
From: Georgetown TX
Thread Starter
Drifting
Joined: Dec 2012
Posts: 1,504
Likes: 73
From: Georgetown TX
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
That isn't very accurate, and if it's slipped, not accurate at all. You wouldn't know if the timing (distributor) was off (since you have a problem) or if the DAMPER had slipped.
Make a "J" shaped piston stop out of a coat hangar. Stick it in #1 cyl, bring piston up till hits. Mark damper. Turn backward until it hits again, mark damper again. TDC is dead center between your marks. Is that where you OEM mark is?
Make a "J" shaped piston stop out of a coat hangar. Stick it in #1 cyl, bring piston up till hits. Mark damper. Turn backward until it hits again, mark damper again. TDC is dead center between your marks. Is that where you OEM mark is?
Melting Slicks
Joined: Dec 2009
Posts: 2,226
Likes: 284
The ones that I've seen that have slipped were like 50 or more degrees out. Finding tdc through the spark plug hole on a sbc is a pain.
Another way to check it is to remove the crank pulley, line up the mark to the v notch & feel or look if the crank key is at the 1:30 position.
Another way to check it is to remove the crank pulley, line up the mark to the v notch & feel or look if the crank key is at the 1:30 position.
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
You can check your harmonic balancer by lining up a straightedge with the side of one of the spokes:
It's advanced from the groove by a slight amount. I don't remember the exact number, but it's something like 6°.
It's advanced from the groove by a slight amount. I don't remember the exact number, but it's something like 6°.
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