Hey Paul,

 What do you think of designing the coolant and oil heat exchanger systems
 to
 be somewhat self contained and modular?  I realize that cooling issues are
 getting pretty well licked on the rotary, but I can't help but think
 things
 could be even better..

 What I envision is building the inlet scoop and diffuser to attach to one
 side of the exchanger, and the outlet plenum and restictor flap attached
 to
 the other side of the exchanger.  Attach this whole assembly directly to
 the
 motor mount.  Where exposed to heat from the exhaust, the construction
 would
 be of metal, but otherwise composite.  The rest of the cowl would be
 designed to attach to the firewall, and ot the exchanger plenums.  Louvers
 would be used to provide direct ventilation for the remaining engine
 components, and to reduce problems related to heat soaking after shutdown.

 A couple of the benefits are:

 - Direct/idealized control of airflow to/through/from the heat
 exchangers,
 allowing smaller, lighter, and more efficient installations

 - Elimination of the "pressure cowl."  A pressure cowl mandates
 relatively
 heavy, stiff sections in order to maintain effective sealing around the
 heat
 exchangers.  The pressure cowl must contain (withstand) the dynamic
 pressure
 associated with ram inlet air at flight speed times the total containing
 area - significant forces involved.  Additionally, since the pressurized
 section involves many penetrations for controls, structure, and
 instrumentation, the sealing becomes piecemeal and complex.  If the
 critical
 pressurized sections are contained around the heat exchangers, the rest of
 the cowl becomes essentially a lightweight fairing around the engine.

 Another idea I had was to design the exhaust system so that much of it is
 external to the cowl..  Some people would think this is ugly, but I
 maintain
 that proper design would make it adequately aerodynamic, lower the heat
 load
 in the cowl, make inspections much easier, and thus represent an
 improvement
 in efficiency and safety.  I have seen quite a number of artfully designed
 and constructed motorcycle exhausts that i don't think would be the least
 ugly were they mounted on an airplane..


 Matt-

 Good idea Matt. Good write up too.

 Paul Lamar

Matt,
I'm of the same opinion in regard to the muffler. I have in mind a muffler
blended into the cowl, which looks like half in and half out . However it's
all external as the muffler, it sits  in a concave section, either on the
bottom or bottom side - what ever works out the best.
George ( down under)

Yes, exactly George..  The concave section being of (or lined with) metal.
I possible challenge here is making the joints between the exhaust tubes and
the muffler body easily inspected..  Good design should make it possible
however.


Matt-