I can send a picture of a non-flying rotary powered aircraft. Hope to

fly before summer '02. I have question for Tracy- What size of muffler are
you using now that you put the muffler under the airplane? I have access to
a bunch of 4.495" and 4.5" dia .020 thick inconel tube for around $12 a
foot. Could you run a perforated 3" dia exhaust pipe through a section of
the inconel tube, pack it with SS wool and hang it under your plane? I've
been vacilitating about my radiator/exhaust configuration, and have been
toying with having an engine cowling like Alan Tolle's, except that the
bottom of the cowling would hang down about and inch or two lower than
stock, with a cowl flap extending back about 2 feet, and the exhaust pipe
exiting the lower left corner beneath the firewall and hooking into a
muffler that  extends from the firewall back to ? The radiator would be
underneath the engine.

Thanks
Brian Trubee
Redmond,Wa

I was at Tracy's place last Monday and here is a picture of his Edelbrock
SS muffler.

Paul Lamar

Tracy Crook wrote:

The Edelbrock is a 3 7/8" x 7 1/2" x 16" as I recall.  It is in Summit
racing catalog in the "RPM" series mufflers.  I don't like it for esthetic
and aerodynamic drag reasons and plan to replace it with a 4" dia X 48" long
home made muffler.

Tracy Crook
rws@altavista.net
www.rotaryaviation.com

I think a bit of streamlining the front and rear would reduce the drag
of that Edelbrock muffler. I did not think it looked all that bad Tracy.

IMHO if you are going to build your own muffler I suggest you make two exhaust pipes
31 inches long (790 mm) dumping into one muffler. That should improve the power.
Everett Hatch confirmed this pipe length on his dyno. According to this
chart it is a 10% improvement over shorter pipes half the length. That would
amount to 18 to 20 HP more. No small amount.

Paul Lamar

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