Alcor

Did anyone ever try to air cool rotors, using a turbo or supercharger to build enough pressure to get decent air flow?
I imagine the max rpm would go up a lot, given proper bearings, but i have no practical experience with this so i have no idea if it's possible.. anyone have a clue?

peejay

Oil works better.

Using a compressor to force airflow will be doing negative work, since the air would be heated when the air is compressed. (This is a fact of life, compressing a gas makes it hotter even with al 100% thermally efficient system)

Trying to make it work with a watercooled engine would be a nightmare. I won't say it's not possible but it would require a massive rework of everything, much much much much MUCH more time consuming than simply getting a bigger oil cooler. Besides, air cooling is never as good as liquid cooling. It's just not as efficient.

Aircooled rotaries drew the intake air stream through the rotor. 2-cycle oil mixed in the gasoline did double duty as bearing lubricant and as apex seal lubricant. I don't think there were any multi-rotor air-cooled rotaries, due to the complexity of the system. And they also had a nasty tendency to overheat and sieze up.

Project84

I don't know how you would have the rotors exposed to air, since they are the one piece that has to be totally enclosed for combustion like a piston in a regular engine. I work on airplanes, and planes have turbocompressors that are like giant superchargers. They are run by hydraulic power and compress air to cool off electronics, and the cockpit. The bearing are air-cooled bearings, so that if the bearings go bad, it doesn't burn oil and blow burnt oil fumes and smoke into the cockpit allow the crew to breathe it in and get dizzy. Those bearings are very expensive due to the microscopic tolerances, and the machining process to make them. The rotors in the rotary engine has too many metal to metal moving parts (apex seals, side seals,etc) to try to incorporate a feasible air-cooled lube system that will be inexpensive enough for Mazda to market and compete against it competition.