> I understand what overlap is when discussing cam and valve timing but
> would appreciate some information about what overlap means when
> discussing crankshaft vibrations and resonances.
If you were able to see through the throws, and looked at most crankshafts from
the end, you'd see that the rod journals overlap the main journals slightly.
Not much, but usually enough that a thin straight line could be drawn from butt
to nose without leaving the steel. However, on a TR6 crank, the throws are a
long way from the mains, and so a straight line would protrude into the air in
each throw. The result is a much "floppier" crank.
Randall
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