Rotary Engines

how reliable are they?

Depends...lol...i've heard that they have some problems, like on the RX-7's...you know, some do, some don't...it's really a random thing...but the new RX-8's are supposed to not have any problems at all...btw, rotary engines own!!!

They can be good, or they can be bad. the FD3s, that's what they call the 3rd gen rx7s, 93 and up, those seem to not last very long. Maybe it's the turbos, or maybe people love driving them so much they they drive them to death. All i know is that my uncle had an 88 Non turbo and it had the original engine at 240,000 miles until he got side swiped. it smoked a bit but still ran strong.

N/A versions of the rotary last a lot longer, generally, than the turbo versions. Reason being the heat. Rotaries run very hot to begin with, and when you add a turbo into the mix...13B-REW, the turbo motor out of a 3rd gen (FD3S) can be made to run extremely high hp, and reliably, only it takes a good bit of money. If you want one to last, get an N/A version.

how does the rotary engines work?

Well, they are quite different from normal piston engines. The pistons and crankshaft are replaced with a reciprocating rotor inside a peanut shaped housing. This rotor, shaped like a ballooned-out triangle, is the 'piston'. There are three chambers in the housing, which are like the combustion chamber in a piston engine. Air is drawn in like normal, the rotor comes around, compressing it, gas is added, then the spark ignites it all, and the rotor's edge comes around and sweeps out the exhaust. That's basically it. Much smoother operation than a piston engine could ever hope for, plus there are only three moving parts compared to 50+ in a piston engine. That should just about cover it. Anyone else, feel free to add if I left out or screwed up something.