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Old 04-26-2007, 01:02 AM   #1
Rat72
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BB Harmonic Balancer Timing Pointer Issues

I've been strugling with a bunch of issues. The 454 that came in my truck had a flat cam lobe which obviously caused lots of issues. The other issue I had when it ran was that the timing would not let the motor even run until I got it to 16 degrees. So I installed a new cam and when I brought the motor up to TDC, the timing mark on the balancer points at .... 16 degrees. I've not done this before but I assume it should point at 0 (TDC).

So, are there different balancers for the different years of 454? The balancer I have looks like the original one and looking from the front, the timing channel (line) is about 8 degrees counterclockwise from the keyway.

Are there different pointers for the different years? The pointer I have is a cheesy chrome aftermarket unit and 0 degrees is very close to where the timing cover raises out to clear the gears.

Or am I just mistaken regarding the timing pinter lining up with the balance line at TDC?

Any feedback would be appreciated.

Thanks,
Whit
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Old 04-26-2007, 01:05 AM   #2
RACINJASON22
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Re: BB Harmonic Balancer Timing Pointer Issues

I'm not real sure on BBC's but, I would almost bet there are different one's as is the case with SBC's

BTW Do ya maybe want this thread moved to engine and drivetrain forum???? You will get more answers there.
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Old 04-26-2007, 09:03 AM   #3
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Re: BB Harmonic Balancer Timing Pointer Issues

I do believe when the piston is at TDC the timing mark should be on 0.
If its not mabey the outer ring on the balancer has sliped.
Or the timing chain is real slopy or has jumped a tooth.
But since you changed the cam, i assume you put a new timing chain on. So thats probley not it.
I would bring it up to TDC and put a mark on the balancer at 0 and tune from there. Mabey get a new balancer.
Just some food for thought...
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Old 04-26-2007, 10:25 AM   #4
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Re: BB Harmonic Balancer Timing Pointer Issues

big blocks are common for the balancer ring to rotate and the mark is out, thats why i powertime for the best result
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Old 04-26-2007, 10:42 AM   #5
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Re: BB Harmonic Balancer Timing Pointer Issues

When I had my 402 I just timed it by ear. Once I got it where it ran the best, I used the timing light. The mark on my balancer would come up around the 12 o'clock area, with my timing pointer in the 2 to 230 region. I think it is safe to say it had slipped a little.
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Old 04-26-2007, 11:52 AM   #6
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Re: BB Harmonic Balancer Timing Pointer Issues

Regarding the outer ring slipping on the crank. Should the keyway in the crank line up exactly with the timing line on the outer ring?

And how does an aftermarket balancer work. Are the original balancers all balanced the same or are they balanced differently? I assume that GM wouldn't do real assembly balance but that they might match parts based on some rough weight calculations.

Thanks,
Whit
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Old 04-26-2007, 12:35 PM   #7
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Re: BB Harmonic Balancer Timing Pointer Issues

Here is an easy way to test to see if marks are right. Line up the bal. mark with 0 on timing tab. Remove #1 plug. Put a straw in plug hole until it touches piston. Turn engine (by hand). If straw starts to go down your marks are right.
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Old 04-26-2007, 12:54 PM   #8
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Re: BB Harmonic Balancer Timing Pointer Issues

Quote:
Originally Posted by jhow66 View Post
Here is an easy way to test to see if marks are right. Line up the bal. mark with 0 on timing tab. Remove #1 plug. Put a straw in plug hole until it touches piston. Turn engine (by hand). If straw starts to go down your marks are right.
The pistion starts going down when the timing line is at 16 degrees before tdc. The piston has gone down quite a ways by the time it reaches 0. I'm very confident that I'm at TDC. I just can't figure out why the timing line is not lining up. Either the balancer has rotated or the pointer is incorrect for the application. I'm leaning towards it being the balancer but the rubber looks fine between the ring and the unit. And I've seen pictures of balancers that have the same timing line to keyway alignment. Mine is about 8 degrees counter clockwise from the keyway. To line up correctly with the pointer it needs to be about 8 degress clockwise.

Thanks,
Whit
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Old 04-26-2007, 10:24 PM   #9
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Re: BB Harmonic Balancer Timing Pointer Issues

A foolproof way is to do this:
1--remove #1 plug (best to remove all so motor will turn easy)
2-- make or buy a piston stop
3--turn motor SLOWLY until it hits stop
4--make mark on balancer at 0 mark on tab
5--turn motor back the other way until it hits stop again (SLOWLY)
6--repeat #4
7--1/2 way between these marks will be the exact TDC for #1
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Old 04-26-2007, 10:37 PM   #10
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Re: BB Harmonic Balancer Timing Pointer Issues

has the bottom timing gear been installed in the stock key slot
most after market gear sets have atleast 3 keyway slots
some have more.

adv
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retarted
?
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Old 04-29-2007, 08:02 PM   #11
Rat72
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Re: BB Harmonic Balancer Timing Pointer Issues

Quote:
Originally Posted by rage'nrat638 View Post
has the bottom timing gear been installed in the stock key slot
most after market gear sets have atleast 3 keyway slots
some have more.

adv
reg
retarted
?
Good thinking. The top gear has 9 but that is irrelevant to finding TDC. Unfortunately the bottom gear has only keyway.

Thanks,
Whit
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