Cub driver wrote in part:
My understanding is that this didn't work very well for exhaust--that the
pilot basically lived and breathed in a foggle exhaust fumes and castor oil
droplets.

Partially correct. The engines were lubricated with castor oil injected (or
mixed with fuel.) No crankcase to hold oil. I think fuel (+ oil) was admitted
to cylinders via a hollow, non-rotating crankshaft. I've been told the engines
ran flat out almost ll of the time. Don't think thjey had a throttle. Had a
"kill switch" on control stick. Incidentally, these engines had impressive
power-to-weight numbers. Furthermore, essentially nothing reciprocated. Each
piston, for example, traveled in its unique circle -- reciprocated compared to
cylinder, but circled in relation to the world. Very smooth engine.

I've read that at the end of WWI some rotary-powered planes reached 20,000 feet
regularly. At that altitude I bet the pilots were so hypoxic they shot down
their wingmen as often as the enemy.

Quent