A rotary engine doesn't have intake or exhaust valves, like a two-stroke piston engine and it also has to have oil injected with the gasoline to lubricate and seal the rotors against the rotor housing just as a two-stroke has to have its oil and fuel mixed.

Do rotary engines have cylinders?

Rotary Engines

One, often called a radial engine, has conventional four-stroke cylinders but the cylinders and pistons are arranged radially around the crankshaft. These engines always have an odd number of cylinders driving the shaft.

Do rotary engines have pistons?

A rotary engine is a barrel-shaped internal combustion engine that lacks many of the major parts you'd find in a conventional piston engine. For one thing, there are no pistons chugging up and down.