>> > > >>> >
>> > > >>> > > Big Snip
>> > > >>> > >
>> >
>> > > This fix is probably best for new motor mounts using existing
>> beams.
>> > It lowers the beam and inch or so and consequently it raises
>> > the thrust line an inch or so if the motor mount is already welded
>> > up. If new mount is being made the mount can be adjusted to get the
>> > thrust line in the right place.  The four plates are .065 thick
>> > 4130. Best to put the nuts on the back side of the flex
>> > plate.
>> > > Paul Lamar
>> > > Also clears the counter weight.
>> > > Paul Lamar
>> > > The Rotary Engine NewsLetter. Powered by Linux.
>> > ACRE NL web site. http://www.rotaryeng.net
>> > Copyright 1998-2005 All world wide rights reserved.
>> > > Hi Paul,
>> Since the box beams were bent up to match the width of Tracy's
>> spacers,
>> the tabs would make it too wide, so the existing beams couldn't be
>> used
>> with this mod.  How about welding a supporting structure to the
>> bottom
>> of the beam in the center where the box structure has been cut
>> back?  I
>> would think the box could be cut back to a 'U' section in the
>> center if
>> the right strengthing member were added to the bottom.
>> Bob W.
>> Please measure your beam width for me Bob. Should only be 2.70
>> inches wide.
>> The spacing between plate and engine should be 3.050 or 3.080 I
>> forget
>> which.
>> If the spacer lengths are less than that you might have a problem
>> with your PSRU.
>> Paul Lamar
>>
>
> It looks like the design is a little different than I thought.  Now I
> see that the spacer goes all the way thru the box instead of being
> internal.  That makes sense as the box dimensions aren't critical.
> Sorry for jumping the gun there.
>
> I have ordered a S-beam from Jerry, but don't have it yet.  I'm
> using the MM plate at the moment.  I want the option of converting to
> the S-beam later, but after the plane is flying! :)
>
> Bob W.
>
> --
> http://www.bob-white.com
> N93BD - Rotary Powered BD-4 (real soon)
> Prewired EC2 Cables - http://www.roblinphoto.com/shop/
>
> The design is  rather subtle. One must remember that the gear box
> greatly
> increases the torque on the prop. In the case of the 2.8:1 gear box
> the
> prop torque with a P-port engine can be as high as 560 ft pounds.
> This torque must be reacted by the motor mounts. If the motor mounts
> are on the engine, such as some bed mounts are, the torque must pass
> through the spacers. If the motor mounts are on the PSRU plate, like
> yours and my current set up are, the spacers only see 200 ft pounds
> max. Same
> with the S beam. The torque load goes directly into the S beam through
> the two 10 mm bolts and then into the motor mounts. The wide spread
> rubber bushings then see a reduced torque load of about  +/- 250
> pounds.
> Since engine, psru and prop weigh only about 250 pounds one
> rubber mount has - 125 pounds and the other +375 pounds. This is
> only when
> the engine is generating peak torque. This is peanuts when it comes to
> a six G pull up or a hard landing. In that case the bushings are
> seeing
> 750 pounds each or more. Up to 900 pounds depending on the exact
> weight
> of the engine and the torque being generated. This why it is so
> important
> to design and weld in the reinforcements around the larger top hole
> properly.
>
> At full power, 200 MPH and net prop HP of 160 there is also a radial
> or prop thrust load on the mounts of 288 pounds total. Each mount
> would
> then be seeing half that or 144 pounds in the radial
> fore and aft direction.
>
> BTW This simple and brilliant MM idea was invented by, the designer
> of the Piper
> Malibu and used on the Questair Venture, Jim  Griswald. Those
> that have flown in Questair Ventures tell me it is one of the
> smoothest
> airplanes flying.
>
> Paul Lamar

Bob,  I will not be shipping any S-beams until we have this problem
worked out to everybody's satisfaction.  However, today Fed-ex should
be delivering my plug wires and I will figure out which coil will be
firing which plug and get the info to  you.  I am really looking
forward to seeing how it will look with the injectors and coils/plugs
hooked up.     Jerry

Now I must confess to being confused -- Based on all the messages &
proposals, I am no longer sure what should be done.  And I am
reluctant to move forward, since I can't tell if my last 'plan' is
still the right way to go.  Anyone want to tell me if I am about to
make matters worse?

Mark

To unconfuse me Mark what was your last plan?

BTW I got your slide throttle parts from Tom Webber. We need to talk
about your intake manifold plans, water pump and alternator
mounting.

Paul Lamar