[Dragncar]

Originally Posted by Jay S

I am not a fan of the PP balancer either, or really any of the 2 piece polymer bonded balancer’s that are bigger in diameter or heavier than stock for more harmonic control. For starters the heavier inertia ring is harder to keep in place. If it does fail, instead of a stock PMD dampener that was probably designed for around 3000 rpm, you now have a dampener that is designed for something closer to 4K, and when the elastomer fails, it is now allowing amplification of the harmonics instead of dampening them. Where you see the stock PMD harmonic balancer mostly breaking cranks in front of the number 2 main, now that same stress point is going to be further back on the crankshaft. When it fails(and they commonly do on heavy cranks) I think it ends up moving the worst harmonics closer to the center of the crank. When it does it’s job it will help over a stock unit, but if it fails it is worse than stock. I know lots of builder’s use those type of balancer’s on engines like a SBF or a SBC, but I think they really do not work very well on a nearly 80 lb PMD racing crank.

JMHO, I’d rather spend the more money for something that does it’s job better, and is lighter weight like an ATI or similar that has inertia rings inside the case of the outer ring.

Do you know what the construction of a BHJ balancer is all about. ?