Paul,
Thank you for your time this afternoon. I learned a lot and more
importantly, I learned there is a lot more that I don't know. Please
put me on your email distribution list for the news letter.
Apparently I was on your distribution in the year 2010.
Gary
Here is that book I mentioned at the hangar.
Scientific Design of Exhaust and Intake Systems. Philip H. Smith and
John C. Morrison Published by Robert Bentley. ISBN 0-8376-0309-9*
http://www.rb.com
Gary had an idea of connecting the bottom mounted radiator air outlet
to the coaxial muffler. This will work if the outer pipe is large
enough.
Try the coax muffler. Less drag for an external muffler and a lower
note tone. The main problem with rotary noise is the high frequency
component.
It works a little bit like a ram jet, ejector or thrust augmenter so
it does not add too much to the aerodynamic drag. The tone of the
rotary sound is much more pleasant.
Also it can be visually inspected so it won't plug up if it ever
cracks.
Paul Lamar
-------------------------------------
Gary,
The tricky part is to get the exhaust past the motor mount and still
keep the MM
in the cowl. This is were Rhino 3D is invaluable.
Looks like you will need a few bumps on the cowl. This is a 13 B
I will redo it for a RX8 side exhaust. Exhaust Bends are limited to
about a 3 inch radius.
Paul Lamar
Paul,
Because of my narrow cowl my PSRU mounting plate will also have to
be narrow...At that station where the plate is, the outside width of the
cowling is 21 inches. You said you had a dimensioned drawing of the
1/2" plate with the bell housing/PSRU bolt pattern. Could you forward
that to me?
Thanks,
Gary
You are in a rock and a hard spot :) There is no magic. Exhaust
pipe is exhaust pipe.
If you some how make a sharper bend it will affect the power or melt :)
Make your airplane wider by a few inches :)
In the over all scheme of things it won't affect the drag that much.
The wing is the big drag gorilla in the room.
Paul Lamar
Paul, the fact is most planes would be LESS draggy if wider.
Witness the Questair Venture. When people told them it was too wide,
they said to be the optimum shape for less drag it would need to be wider!
Bill Jepson
Its true. An RV6 is less drag than an RV4.
Paul Lamar
I need an engine mount attach point on the top of the engine. I see
in the pictures here that they seem to be grabbing onto something
immediately forward of the alternator pivot bracket.
The aluminum alternator attachment doesn't seem to me to be strong
enough to serve as a critical engine attachment. I was thinking of
using a long rod, threaded at both ends, to tie the alternator
bracket to the flange that mates to the bell housing. That would
make a much stronger attach point for the engine mount.
Gary
The problem with that is interferes with the tuned intake manifold.
The best way is use a short strut from the oil pan to the nose gear.
Don't forget to reply to the right thread or subject.
The right subject for your airplane is "Tandem airplane"
Paul Lamar
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