Quite so Matt, but car engines are watercooled.
And rotary aircraft engines have a large supply of cooling air rotating about, and a VERY plentiful lube oil supply - blowing out all over you !
Military engines have a VERY short overhaul life.
Wasn't the Merlin initially rated for 20 hours of combat use between overhauls - and that was another era of engines later.
Incidentally, early Camels etc had no throttle control, the carburettor was full throttle all the time, you controlled the speed with
the magneto kill switch - brrrr brrrr brrrr brrrr.
It took the motorcycle world a while longer to adopt alloy pistons that were reliable enough ?
AJS were experimenting with them in the early 1920s - and won the Senior (500cc) TT with a 350 engine
at some point there, the SAME engine that had won the 350cc race.
JAP were still offering iron pistons into the 1930s, and I've seen mentioned that Bedford trucks used them into the 1950s. ?
BTW, those rotary engines you show were said to be heavier than the rest of the aircraft, including the pilot.
With that massive chunk of metal rotating up front, apparently if you let go of the stick at any point, the
torque of the engine would mean the plane would try to rotate around the engine, and do a lightning fast flick turn.
Useful in combat to get away from folks that were shooting at you, but on takeoff a real killer, literally....
