Stroke

7+ 2 Stroke Engine Diagram. The inlet ports lead into the bottom of the cylinder which is open to the crankcase: [2] the engine is able do produce power after one cycle because the exhaust and intake of the gas occurs simultaneously, [3] as seen in figure 1.

This type of engine needs no conventional valves. At the top of the cylinder are typically two or four exhaust valves that all open at the same time. There is a valve for the intake stroke that opens and closes.