Joseph M Berki wrote:

Paul,
        Thanks for the input.  The landing gear pivot bolt is a 1/2"

stud that

secures the main gear by trapping it between two bulkheads like the Cozy
MkIV.  The rear hard point is boxed from the firewall to the rear landing
gear bulkhead.  Exhaust: What is the space required for the tightest SS
tubing used for the exhaust?  There is room.  Rear mounts: What size

tubing

is used to support the isolators?  It looks like 1" very short stub with
just enough length that the tubes have something to weld to.  I am

assuming

that the arrangement in the pics for the rear mount will not work?

Generally speaking a 3 inch center line radius is about
the sharpest radius you can find. That makes fitting the
exhaust into this type mount rather difficult even using
two inch exhaust SS tubing. It is also not good to have
a sharp radius as soon as you exit the exhaust ports as
that is a good way to burn a hole in the bend.

Here is a 3D. I will see what I can do to fit in some exhaust
tubing tomorrow as I need to go pick up some manifolds from
the machine shop today. This could be a big waste of time unless
we plan ahead carefully and make sure everything fits.

What is the distance from the lower firewall hard point
to the upper firewall hard point?

Paul Lamar

Ok Joe a couple of 45 degree SS 2 inch pipe bends on a 3 inch center line
radius  from RB Wagner will clear the motor mount tubes but you
will have trouble getting a muffler under the cowl.

Here is another way of doing it.

This is the P51 motor mount trick basically. You will still have to
brace it diagonally back to the spar. You will then have room
close to the engine for a simple hollow tangential muffler
made from .065 SS. This is about the only way to get a muffler
in a tandem pusher. Tom Jordan did something similar
in his Limo EZ.


Paul Lamar

Joseph Berki wrote:

Paul,
         Thanks again for all you help.  The distance between the upper
hard point and the lower hard point is about 20" ( at work now will measure
later)  There is about 4 to 5" clearance between the block and the tubes,
the rear exhaust port is closer than the forward.  The muffler will go
below the motor as the radiator is way in front of the motor.  I have cut
more 1/2" 6061 T6 to make the holders you described and will order some
more 4130.  Should I tie the rear buckets together with a cross member?  It
will have to be bent.  This would result in a box around the bottom of the
motor front and rear cross member and the Schertz beam.  I would like to
make the diagonals to the spar removable so a plate at  the bucket would
permit them to be bolted to the mount.

Joe

Where in front of the motor is the rad going? What are the rad dimensions?
I'll put it in the 3D.

Paul Lamar

4.4 inches is what I have on the 3D between block and upper motor mount
tube. Too tight for a 90 degree exhaust pipe bend. A three inch radius and a two
inch pipe require four inches minimum. Then of course the exhaust
gases would do their damnedest to burn through the bend :)

BTW what psru are you planning on using? 

Paul Lamar
 
The AirCraft Rotary Engine NewsLetter.  Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/            
Copyright 1998-2003 All world wide rights reserved.