Speaking of the tangential tuned muffler I had a lot of complaints
saying it was impossible to weld so I came up with an idea
to make it easier. This is two inch tubing bent up on a 4 inch center
line radius with a six inch center can. Actually slightly less than
6 inch diameter. The can is fabed separately and holes cut and
it is slipped in to the pre welded spiral tubes. Bolt holes are matched
drilled and sheet metal screws are used to hold the can to the tube
flanges. The sheet metal screw heads are drilled and safety wired.

The outlet pipe is best brought out of the front of the can with
a 180 out the side of the cowl with an optional fish tail
to cut the noise further. No problem to fit this in to a wide
Schertz beam motor mount without the P51 type MM beam feature shown
here.

Paul Lamar

The tubes can spiral up (recommended) or spiral down.
The 12 inch long core can could favor the front or back of the engine.
One of Jerry's cooling tubes could be welded into the center
of the can and a 2-1/2 inch diameter down pipe could come out
of almost anywhere. Here is the complete set of 3D's.

Is this buildable Ed?

Paul Lamar

Edward Klepeis wrote:

Dear Paul
        Your easy tangential muffler looks good  but there is one problem.On
a motor mount like jerrys it wouldn't fit. I had approx. 1'' clearance
between mount tubes and exhaust tubes all around top, bottom,and side. Also
you would have to rotate the can upwards to clear motor mount tubes putting
the top tube closer to the intake I don't think that is a good idea.As it is
jerry and I are talking about putting some kind of heat shield between the
top of the exhaust and the bottom of the intake to take some of the heat off
the intake. I'm open  for ideas.

Regards

Ed

That why you might have to use the P51 side beam type mount so all
MM tubes go UNDER the muffler. Most cowls are about 40 inches wide
so half of the engine is about six inches. This muffler is about
ten inches OD. That gives a total 16 inches out from the center 
line plus an inch or two. That leaves in theory about two to four 
inches of cowl clearance. Some cowls are even wider than 40 inches.
It obviously will not work on a tandem RV4 or RV3. I might
work on a tandem RV8 as they use the same cowl side by side airplanes
use. Here is a 3D of the P51 type side beam MM.

A slightly smaller OD version of this muffler could be made if you used
1-3/4 inch OD tube bent up on a 3 inch center line radius with a smaller center
can. that would give you a 4-1/4 diameter center can. Over all would
be 7-3/4 inch diameter.

Paul Lamar
 
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