[tornado-tech]

Was setting timing on my 408 and when I set it last year, it had 18 degrees initial. When I checked it 2 nights ago, it showed 32 degrees initial. If i put it back to 18 degrees initial, it barely runs. I tried another timing light last night and it showed the same thing. I think my harmonic balancer hub slipped. The question I got if I go with a different balancer that is SFI approved, would I need to rebalance the motor since it is internally balanced and was balanced with the flexplate and balancer? The balancer now on the motor is a Pioneer 8" balancer

[Infomaniac]

Sounds like it sllipped.

You should not need to rebalance if you use the same size balancer.

[k-star]

striaght up swap no need to re-balance...

Make sure you check the bore size in the new balancer, many times they are undersize....

Keith

[Oldphart]

I'd use a piston stop (very carefully) to find the true TDC and see if the mark lines up before I spent the money for a balancer.

[MI2600]

When you checked the timing this year, was the vacuum advance disconnected?

I actually know someone who did that very stupid thing.

[tornado-tech]

Yes the vacuum advance was disconnected. I just did the piston stop check and the marks were off 14 degrees also. What if I went to 6.625" SFI balancer to replace the 8" non SFI balancer? Would that need to be rebalanced if the 6.625" balancer weighed 10.37 lbs while the existing 8" weighs 10.4 lbs?

[xntrik]

Originally Posted by tornado-tech

Yes the vacuum advance was disconnected. I just did the piston stop check and the marks were off 14 degrees also. What if I went to 6.625" SFI balancer to replace the 8" non SFI balancer? Would that need to be rebalanced if the 6.625" balancer weighed 10.37 lbs while the existing 8" weighs 10.4 lbs?

Overall weight has nothing to do with balance.

[Rob Keller]

Balancers slip more often than most think

make sure you use the proper tools for removal & installation beating it on with BFH is not proper installation


Rob

[tornado-tech]

The balancer did slip as I just finished putting on a TCI Rattler 7 1/4" balancer with a Summit timing pointer. The timing was right at 18 degrees inital as it was the when I set it last year. As far as aftermarket balancers and heating them to let them expand so they will slide on easily will void the manufacturers warranty (at least TCI's it will). It easily went on with a Moroso balancer installer and did not require a hone job due to tighter tolerances. Definitely one of the easiest balancer installs ever done.

[Mr. Wormy]

older model harmonic balancers have different timing mark on them

[Infomaniac]

I do put them in an oven at 200 degrees. The engine gets 200 degrees so it should not harm the balancer.

A lot of them need honed to proper interference fit. The ATI superdampers that I use all need honed.

[SecGenLvr]

Originally Posted by Oldphart

I'd use a piston stop (very carefully) to find the true TDC and see if the mark lines up before I spent the money for a balancer.

This is probably a good idea, fixing a possible problem, may lead to more work and no fix...

[Rob Keller]

I use a bolt grip puller to remove it.

I use a Harmonic balancer installer to install

the only one I know of that Does Not requires I installer is a old PONTIAC'S 350 ,400,455


R