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Okay I have my engine together and the timing mark is way off. By three and a half inches. I bought one from Summit and besides being new it is the same. I have a 69 with the 350/350.
Do any of you folks have a idea where I can get the proper harmonic balancer ?
Have you considered it's not the balancer but the timing tab on the cover?
Yes a friend of mine brought that up this evening.
I'm going to do a search and see what pops up. I may just do as I would have twenty years ago and make my own mark on it.
Yes a friend of mine brought that up this evening.
I'm going to do a search and see what pops up. I may just do as I would have twenty years ago and make my own mark on it.
Okay I have my engine together and the timing mark is way off. By three and a half inches. I bought one from Summit and besides being new it is the same. I have a 69 with the 350/350.
Do any of you folks have a idea where I can get the proper harmonic balancer ?
There are some variations on timing marks out there whether the pointer is for a 12 o’clock pointer vs a 2 o’clock etc. Here is a link that might help.
There are some variations on timing marks out there whether the pointer is for a 12 o’clock pointer vs a 2 o’clock etc. Here is a link that might help.
Is this image showing the mark position with the engine at TDC #1?
Are you sure it's not set at TDC #2? (#1 is the forward driver's side piston while #2 is the forward passenger side piston.)
Are both of your valves on #1 cylinder closed with the#1 piston at TDC? Is the dizzy rotor pointing at your #1 spark plug wire?
IMO - Harmonic balancer slippage does happen, but that would be a LOT of slip, and the spacing, being pretty exact at 45 degrees is suspect, as 67:72 points out.
Is this image showing the mark position with the engine at TDC #1?
Are you sure it's not set at TDC #2? (#1 is the forward driver's side piston while #2 is the forward passenger side piston.)
I have it at TDC on one..
Very positive it is timed right.
Very positive I'm going to add my own mark to it.
I have spoken to a few different people about it.
I even had a master mechanic come take a look.
My work is right.
I didn't take a shot of that.
I had a good friend that's a Master Mechanic look at it. It all check out as installed and timed properly.
I picture of the timing chain is not important here. In fact, you don't even have to have a chain installed.
What IS important is the relation of the key-way on the balancer and the TDC mark on the balancer in relation to the pistons position in the bore, TDC
The cranks keyway position, balancer mark is the issue, not where the camshaft is.
I picture of the timing chain is not important here. In fact, you don't even have to have a chain installed.
What IS important is the relation of the key-way on the balancer and the TDC mark on the balancer in relation to the pistons position in the bore, TDC
The cranks keyway position, balancer mark is the issue, not where the camshaft is.
Key way is at 12:00 number one at TDC.
My timing marks are aligned next to each other.
I'm making my own mark on the hormonic balancer and running it.
Gotta get a good carburetor to bench test it and break it in. I will know then if I F'ed up something.
Chevy used at least two timing mark locations over the years. And it moved by a couple inches. And there is no telling what parts or combination of parts you actually have on there now after 50 years. The timing tabs and balancers need to be a "matching" style set.
Or the balancer could have slipped on the rubber.
You could verify TDC of your engine with a piston stop and put a mark on 0 of the timing tab you have. Very easy to do with the engine out of the car. Doesn’t matter what version harmonic balancer or timing tab you have, it will definitely be correct.
Key way is at 12:00 number one at TDC.
My timing marks are aligned next to each other.
I'm making my own mark on the hormonic balancer and running it.
Gotta get a good carburetor to bench test it and break it in. I will know then if I F'ed up something.
Keyway at 12:00 is not correct. You are not at #1 TDC.
Look at the pic I posted, your balancer (engine) needs to rotate to match it.
Your keyway should point near to the timing cover bolt indicated by the red line above.
Use a piston stop & confirm.
#1 on a SBC is driver's front.
Then use this guide to tell you where the mark on the balancer should be vs the keyway slot: That will tell you if the balancer is good.
SBC engines have three (3) different timing pointer locations:-
Pre '69 engines, TDC mark is 2° to the left of the keyway centre line;
'69 and later, TDC mark is 10° to the left of the keyway centre line; and
1984-'95 engines, TDC is at 12 o'clock position on the damper.
Last edited by leigh1322; Apr 20, 2024 at 03:33 PM.
Harmonic balancer
