Vibration damper flywheels

[Bob Culver]

Whilst 2 brg Seven engines and esp high cr ones are harsh is it usually very evident as physical vibration at reasonable revs or mainly as din? Do others encounter significant steering wheel vibration? Is the engine token rubber mounted? The simple RP mounts make a big difference. The fact that cranks so often fail at the rear journal implies major involvement of the flywheel as the direct bending there should be minimal. (Bridges do not fail at the ends) The life of the phoenix crank is due mainly the fatigue protection provided by nitriding. Whatever the steel the rigidity is the same for the same shape. Torsional vibration problems are usually assocaited more with high rpm and multi main bearing carnks with many heavy counterweights.
Ideally crank dynamic balance error should not be corrected in the flywhee but the presence of the key complicates matters somewhat.