Unrelated:  For a Renesis based engine, are the side exhaust ports
  closer to the prop than the 13b setup you depicted here?    Or are
  they closer to the firewall?  How does the muffler fit?


  Thanks,

  Matt-

  Yes they are.  I have some 3D models of that.
  There are three exhaust ports so they are both closer to the
  firewall and closer tothe prop.

  Paul Lamar


Looks like there's plenty of room for a muffler outboard of the motor
mount tubes on the "Kevin*" models.  Is that for a side-side 2 seat RV
(-6A, -7A)?  Something like that could work for a Cozy which might
have a similar firewall width.  No nose gear to louse things up..


Matt-

Side by side RV6.
That one is not the best example as the the S beam chosen is a simple
aluminum plate with closely spaced rubber bushings. That always causes
problems wiggling the exhaust system down and out due to the proximity
of the motor mount tubes. Several people have found that out the hard way.
Not to mention the aluminum plate conducts a lot of heat into the rubber
bushings. Speaking of heat, an unshielded exhaust pipe acts like an infra
red heat lamp heating up what ever it can see. Heat shields on exhaust
system are essential to prevent this.

Here is a more typical example. There are two version. In the 180 version
the shielded stock manifold is mounted in the stock position. That means
the exhaust comes out at the front of the AC engine in a tractor config.
One would need a heat shield around the 180 degree bend to keep it from
heating the rubber bushing. See the 3D.

Flipping it around you can have the pipe come out the back and down if you
fabricate a custom manifold and heat shield. 3D2. Perhaps it would be
easier
to do surgery on the stock flange to get the bolt holes in the right
position and flip the stock manifold.

Paul Lamar