"MrV" wrote in message
oups.com...
actually i'm thinking 4th or 5th gear from a 6speed manual tranny.
from the LITTLE research i've done
3rd gear is like 1.43 and 4th is like 1.2 seems like a good range
3500rpm= 2400 prop rpm
or at 1.2 3250 rpm = 2700 prop rpm.

now wouldn't the prop vibs be less than the abuse the average tranny
takes from a daily drive ?

Resonate vibration is the killer in the aircraft powerplant world.

At every power pulse, the crankshaft winds up a little bit, and then unwinds
while waiting for the next power pulse. This can be a very large problem,
and can destroy a drivetrain. Aircraft engines get around it by making a
very stout driveshaft, but even then, some engine prop combinations are
plackered not to run at certain RPM's in continuous operations.

Do some research. There have been tons written on the subject, and even
though it does not make sense, driving a prop is way harder than a car
wheel, and avoiding the resonate problems.
--
Jim in NC