Anderson Ed wrote:

Prop pulse and exhaust pulse out of syn is certainly an interesting
hypothesis.  I have a two blade prop and two mufflers (one for each
exhaust port) which dumps the exhaust pulse about three feet further
back than exhaust pipes dumping straight out from under the bottom cowl.
Assuming the prop/exhaust pulse theory has merit, this may explain why I
don't seem to have the vibration (or at least not strong enough to be
noticable) in that perhaps the prop pulse and exhaust pulse are both
diffused enough to not interact by the time they are in the airstream
together. my 0.02

Ed Anderson

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