Please, some thoughts about counter-rotating props using twin Mazda power
(one on each wing).

In fantasy land, we turn the rotors around and run the Mazda backwards. I
don't think even Paul could figure that one out.

By the way, very nice article in June 2009 KITPLANES,  Paul.

I've been unable to find a suitable reversing gearbox. So far, I've thought
of putting a "sandwich" gearbox between the engine and the PSRU. I know
this is easier said than done. You could probably use gears from an auto
transmission. As each engine with the accessories has to be the twin of each other
(except for the rotation part), both need the gearbox.
With a straight-through arrangement you would need 3 gears (input, idler,
output) for original rotation, and input, two idlers, output, for reversed
rotation. For an offset arrangement, one idler can be subtracted from each
gearboxe. Oil squirting barbs at all gear meshing points.

Initial problems are the input adapters from the engine, and the output
adapter to the PSRU.

This is as far as I have gotten with my brainstorming, and I am sure that
there is tons of stuff that I am missing, so please feel free to critique -
something I have learned to value in reading your daily posts that I get in
my daily email.

By the way, the object of all this is a 60% P-38 in which rotary engines
are the only ones that make sense for physical room and power. Also, it only
works if the inside of the cockpit is laid out like a sailplane (recumbent).
Thank you all, I have learned to enjoy your fearless, open-minded ways.
        Bernie.