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Old 07-06-2004, 10:04 AM   #1
n737nc
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Question about harmonic balancers...

Still green, getting the stupid questions out of the way.

If you have one size balancer, do you have to stay with that same size?

Reason that I am asking is I have a larger balancer on my motor(7.5inch). But, the balancer is too narow that the timing tab covers it up(picture). So, when I time the motor, I have to time it to 16, then guess from there.

Can I change my balancer to a smaller one? If so, what size do I need?

Thanks,
Nick
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Old 07-06-2004, 10:41 AM   #2
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I would just go down and get a different timing tab, or trim/bend the one you have to fit. You could also mark the front of the balancer with white paint where the timing mark is.
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Old 07-06-2004, 10:43 AM   #3
JimKshortstep4x4
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You can change the balancer if it is an internally balanced engine, but what I would do is paint a white line on the front of the balancer. Just extend a line from the groove that is in the balancer.

The timing light will pick it up and you will be able to see the mark.

I don't understand what has created your situation. It looks like the pointer is the wrong one because the face of the balancer is in the right location.

Jim
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Old 07-06-2004, 11:22 AM   #4
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Is that a chrome timing cover? I think I see a reflection...that might explain why the timing tab is longer. Just a thought.
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Old 07-06-2004, 11:58 AM   #5
n737nc
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Thanks for the replies.
Yes it is a chrome timing cover. That is getting ready to change though. I have been having a problem with the front main seal leaking between the timing cover and the oil pan. So, I bought a new pan and timing cover. Going to pull the motor out this week to replace them(along with some other parts).

I thought that the balancer was wrong because it seems to run better when it is more advaced(more towards the top of the balancer). I was thinking that the timing tab should be at the top of the timing cover, instead of on the side. But with my short water pump, there would be no way to see the timing tab if it was moved up there.

Is the timing mark in a different location with the different size balancers?

Thanks for everyones help.

Nick
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Old 07-06-2004, 12:17 PM   #6
JimKshortstep4x4
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Some of the newer engines have the timing tab on top as you were suggesting but the 67-72 truck engines have the timing as your picture.

The other possibilities are that the outer ring on the balancer has slipped or that you are setting the timing with the vacuum advance hooked up.

Jim
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Old 07-06-2004, 12:40 PM   #7
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On your oil leak. Check the shaft on the balancer. If there is a groove worn where the seal is, you need to either put a redi-sleeve on the shaft or replace the balancer. I would suggest a new balancer. The rubber is old and worn, quite possibly has slipped. If your engine is not externally balanced (400 ci) you can go up or down on the balancer size. Also, I would replace the timing tab at the same time.
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Old 07-07-2004, 07:10 PM   #8
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you could just clean the balancer you have off real good and go too your nearest performance parts store or jegs.com and order a timing tape for your size balancer and stick it on
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Old 07-07-2004, 07:41 PM   #9
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Quote:
Originally Posted by willow72
you could just clean the balancer you have off real good and go too your nearest performance parts store or jegs.com and order a timing tape for your size balancer and stick it on
ditto. very helpful piece and not much dough
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Old 07-08-2004, 09:02 AM   #10
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Quote:
Originally Posted by Quagmire
ditto. very helpful piece and not much dough

I have never had any luck with the tape sticking(and staying) Proform makes a balancer cover that is a nice and cheap piece. I always take and mark a line on the front of the balancer..from the outside ring to the inside ring..that way you can see if the outside ring slips
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Old 07-08-2004, 05:15 PM   #11
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yea i forgot about those they are about 30$ aint they? are they hard to put on?
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Old 07-08-2004, 10:53 PM   #12
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Chevy used two different balancer with different timing marks located differently compared to the keyway. All will work on your engine(if you have anything other than a 400 sb), just your timing marker may not be in the right position anymore. Chevies high performance balancers were mostly 8 inchers while normal sizes were 6-7 inches. I never use a timing light to time an engine, I just advance the timing just until it starts to ping and then back it off a tiny bit. Gets the best power and mileage that way since it maximizes the engines potential to make power.
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Old 07-08-2004, 11:54 PM   #13
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Old 07-09-2004, 02:00 PM   #14
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This is one of those things that if you're going to have it off, and it's original, replace it while you're there. The rubber/elastomer does wear out and won't control the harmonics as well as a new one. If the tab isn't part of the cover, just replace it with a shorter tab.

If it weren't for the leak, I'd say stick with the white paint stripe. Works wonders under a timing light.
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