Engine Timing
Thread Starter
Instructor
Joined: Jun 2015
Posts: 212
Likes: 29
From: State College Pennsylvania
Engine Timing
Is it possible for the timing mark on my harmonic balancer to be off? And if so how do I fix it?
So...I finally got around to timing my engine (finally have a working timing light) and according to the harmonic balancer my engine is approximately 30 degrees advanced at idle and it sounds like it will die before I get to 0 degrees TDC. I know I am hooked up to the #1 spark plug.
Any ideas?
If it helps, I have a 1970 454
So...I finally got around to timing my engine (finally have a working timing light) and according to the harmonic balancer my engine is approximately 30 degrees advanced at idle and it sounds like it will die before I get to 0 degrees TDC. I know I am hooked up to the #1 spark plug.
Any ideas?
If it helps, I have a 1970 454
Last edited by D_Williams; Apr 22, 2016 at 05:14 PM.
Drifting
Joined: Sep 2014
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From: Long beach NY
St. Jude Donor '15-'16, '18
Drifting
Joined: Oct 2005
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From: Forth Worth TX
Are you using a standard timing light or a dial back timing light?
If a dial back, are you using it correctly? Depending on how you have it set, you can get some weird timing indications.
And yes, your timing mark on the harmonic balancer can be off. They can and do slip with time. If that happens, it will need rebuilt or replaced.
One way to check your balancer is to remove all of the spark plugs and turn the engine over by hand (a pain, I know), use a mirror and look in the #1 cyl spark plug hole, you'll be able to see the piston reach TDC (make sure you are on the compression stroke). When the piston reaches TDC, the timing mark should align with "0" zero on the timing tab. If not, it has slipped, making all future timing adjustments off.
If a dial back, are you using it correctly? Depending on how you have it set, you can get some weird timing indications.
And yes, your timing mark on the harmonic balancer can be off. They can and do slip with time. If that happens, it will need rebuilt or replaced.
One way to check your balancer is to remove all of the spark plugs and turn the engine over by hand (a pain, I know), use a mirror and look in the #1 cyl spark plug hole, you'll be able to see the piston reach TDC (make sure you are on the compression stroke). When the piston reaches TDC, the timing mark should align with "0" zero on the timing tab. If not, it has slipped, making all future timing adjustments off.
Thread Starter
Instructor
Joined: Jun 2015
Posts: 212
Likes: 29
From: State College Pennsylvania
Thanks both for the replies!
I may check that at some point, removing the vacuum advance hose helped a little bit and I was able to set the timing. Is it normal for the idle speed to drop a little (~200 rpm) with the vacuum advance not hooked up?
I am using the dial timing light, but I was keeping it at 0 initially (to find TDC) before I set it advance 4 degrees (by turning the dial on the light to 4deg and setting the balancer mark at 0)
I may check that at some point, removing the vacuum advance hose helped a little bit and I was able to set the timing. Is it normal for the idle speed to drop a little (~200 rpm) with the vacuum advance not hooked up?
I am using the dial timing light, but I was keeping it at 0 initially (to find TDC) before I set it advance 4 degrees (by turning the dial on the light to 4deg and setting the balancer mark at 0)
