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

Joe, from the photos it looks like your engine is much farther from the
firewall than mine. Is this based on using Tracy's redrive and putting
the prop at a certain F.S.?  My installation is not one to copy or use
as a reference for a redrive-based installation, just curious how you
are locating the engine. If you get the engine too far aft you may have
to add weight to the nose. Can you use a prop extension on the redrive?

--
Perry Mick
Custom Composite Props
mick@bridgingworlds.com
http://www.ductedfan.com

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