Paul,  Would the efficiency (cooling and speed) improve sufficiently
    enuf to build a P51 style radiator box aft of the baggage compartment up
    into the aft fuselage?  The cowl could certainly
    be smaller and tighter.
    Thanks,  David

    Well perhaps but the big drawback to the P51 style cooling is
    additional frontal area.
    Frontal area has nothing to do with whether the nose is pointy or not.
    It is defined as the maximum cross sectional area of the airplane.

    What is the "frontal area"? The frontal area is the area of a shadow
    you get if you shined a spot light from some distance at your
    airplane parked
    in front of a wall. It is not how pointy your airplane is. It is
    the maximum cross sectional area of your airplane. Larger fuses
    mean larger frontal areas which means more drag.

    On the up side the prop eff. might improve slightly due to the
    pointy nose.

    Also on the up side the exit duct and nozzle for the hot air is ideal.

    Another proplem is the rate of water flow would slow down due to the
    lenght
    of the water pipes. The pump would have to work harder. Also coolant
    weighs
    about 8 pounds per gallon.

    Another down side is the structure of the fuse would have to be
    redesigned.
    Van G would have a fit if he knew you were cutting large holes in
    the bottom of the fuse.

    One of the beauties of the rotary as an aircraft engine is its small
    size. It therefor
    leaves room in the cowl for the rad which simplifies the plumbing
    and in theory makes
    it more reliable.

    Paul Lamar ...No rotor no motor.


Paul,  One of the things I remember from Kent Paser book was he extended
the cooling air exit duct (extended lower cowl aft) and exhaust well
past the firewall on the underside of fuselage to augment exiting air
flow.  Seems I recall it being about 18 inches past the firewall?  Into
a lower pressure area?  Does this still sound viable?
David
ps. Surprised that Mistral didn't use inconel on the entire exhaust,
given the temps.  Hmm, maybe they thought it would get enuf cooling out
in the breeze.
Watching Watkins Glen, and F1 qualifying.

Yes it is. There is a part in the book How to Cool Your Wankel about augmenters AKA ejectors
as NASA calls them. Here is a NACA pdf on the subject.

I'll turn my TV on immediately :)