<< > Does Cessna or Piper use a specific indexing, and does Lyc or Cont
 > recommend this?  I don't remember seeing this anywhere in the factory
 > literature.
 >
 > I had heard a few reports that some positions were smoother
 > than others, just hadn't experienced it myself or read of an official
 > requirement for this.
 >  >>

It is very important to have the prop correctly mounted on certain aircraft
and engine combos to prevent unnecessary vibration, probably due to
counterweights in the engine design and airframe/motor harmonics. The Cessna
205/206 is very susceptible to this malady and vibration is easily corrected
by moving the prop to the correct position(and this was a balanced assy prior
to moving). Dynamic balancing helps but the index on this combo is more
important. Paul, I think the 182 is also susceptible to this (but am not
sure, it is more common on the Stationaire Cessna models). If anyone is
interested I can look up the reference.

I am definitely interested as my A&P IA consultant says it is not
important. 

BTW I now have to take the prop off the new engine and
remove a core sample from the prop flange.. to have it analyzed by
Continental. If the crank is made from bad material the engine
must be removed again and sent back to Continental. 
I will then have to start all over re-installing yet another new engine.
I am about ready to shoot myself and forget the test flight :-)

I am about

Paul Lamar
 
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