> OK Jerry here is the BD4 version. I like the rear
     > beam better. Also I added shims so the downthrust
     > angle can be adjusted.
     > --
     > Paul Lamar ...No rotor no motor.
     >



    Question,  in general is the thrust of an aircraft engine either
    level or down?   Is it ever up?    What about pushers?    Jerry

    Tractors are usually down. Pushers are up. Usually less than 3
    degrees. Spacer or shims would be +/- .75 inch in case you were
    asking? :) In general the thrust line passes through the CG.
    Does not work for Coots and their cohorts in crime :)
    No matter what you do they are going to pitch down when
    power is applied and pitch up when it is reduced.

    Paul Lamar ...No rotor no motor.


Expanding on  what Paul said..  Most tractor airplanes have nose
pitch-up response to increased power setting.  Part of that is increased
air flow over the stabilizer - increasing the pitch response of the trim
setting.

The other part of the picture is where the thrust line is in relation to
the center of drag.  If the the thrust line is below the center of drag,
increasing power causes pitch up, if thrustline is above, pitch down to
increasing power.

I am pretty sure the Varieze and LongEZ don't have any thrustline offset
(up, down, left, right).  Increasing power causes very slow pitch up
because of trimmed airspeed, plus a slight roll effect (but no yaw)
because of torque..


Regards,

Matt-

Excellent explanation Matt. The Questair had an adjustment. You could
tweak it for top speed. That is why I was so in love with the Questair
rear mount for so long. People did not like to modify their
firewall to accommodate it so that is why we went to the new rear
beam mount. "Don't confuse me with the facts I don't like the look
of it" :) Also it was hard to implement when you moved the engine
forward a few inches.