Worried about harmonics....what do I do? Harmonic balancer time?

[Maltman]

Well, I've been doing some reading and I'm starting to worry that the vibrations I feel (mild) at about 2-3k might not be so good. The engine had the vibs ever since the rebuild and are probably made more intense due to the 2 poly engine mounts.

However, it still has the stock hub and I'm wondering if investing in a true balancer would be worth it and, more importantly, what options are available.

I'd like to think that the vibrations are just "normal" events stemming from the "external" bolt-ons (given that the engine was balanced with the flywheel and stock hub)....but I'm really not sure.

It sounds like our stock hubs are questionable after mid 11s and given that they are not SFI approved, I'm thinking the aftermarket world might be needing a call regardless. Any ideas on this?

Thanks,

 

[Ormand]

There is no harmonic damper on the stock Buick engine. The stock hub is a balance hub, NOT a damper. Don't know what your balancer did, but if you have an internally balanced crank, then the flex plate and the balance hub should have been balanced seperately. The BHJ damper is available in either "neutral", or in an imbalanced condition, which would match up with the stock externally balanced crank. If your engine builder put together a combo which is not the stock externally balanced, and is also not using neutral balanced hub and flex plate, that would be a problem. On the other hand, you may just have vibrations due to the engine mounts. You might want to contact HRpartsnstuff- they can help with that. (there's a thread on this board about those mounts)