Question about balancing rotating assembly

I'm not suggesting no one knows anything...I'm just saying that we all know less than we'd like to think. I do believe there is an impressive base of knowledge 'in the world'...but mostly it exists behind closed doors in places that have the chops to create it. Lexus, Ilmor, GM, etc. Sometimes that information leaks out in one form or another and we get to get little nibbles of it.

Harmonics? I dunno. When they first brought out the V10 in Ram trucks, they had an failure point where the harmonic damper would wobble loose. The blame, according to Dodge, was driveline harmonics. I take that mean the engine itself was happy but when you bolted it to the rest of the driveline, it got unhappy.