Hi paul, or tracy

I have asked this question before, but no response.  It may seem off

the wall

however it is a consideration when making the marcotte/crooke decision for
the PSRU.
I have been looking at the motor mount requirements for the RV8 and noticed
that the thrust line is off-set approx 1" to the left of center.  If I now
mount a reversed prop should I consider a similiar offset to the right or
just go centerline?

RV8
Tail,wings,cabin,PA28-180

Is that one inch or one degree. I think you might need to ask Van that
question.

Paul Lamar

  I dont know about the RV8 but the RV4 has the right  mount pads set back
1/4" relative to the left pads to provide thrust offset. The mount pads are
all offset 1" to the left to bring the prop hub back to the aircraft
centerline. I'm not sure (and didnt really care) what that amounts to in
degrees.

  Since Tracy reported no adverse effects by eliminating the offset, and
since most Lyc powered RVs still end up with rudder tabs in spite of the
factory offset, I eliminated the offset when I built my mount. My recall is
that Tracy has a small tab on his rudder that is no larger than typical RVs
with Lyc power.

  In any case, I dont see how this affects PSRU selection. Should be a
simple trig problem to determine the offset in degrees. Then built a mount
to match that number whether the prop turns CW or CCW if you decide you
want the offset.

Mike Wills

The Aircraft Rotary Engine Newsletter.              Powered by Linux.

http://home.earthlink.net/~rotaryeng/            http://www.linux.org