What type of engine delivers power with every down stroke the piston?

A Two Stroke Engine delivers power with every down stroke the piston. In a two-stroke engine, the piston completes one power cycle in two strokes (one revolution of the crankshaft). During the first stroke, the piston moves down the cylinder, drawing in a mixture of fuel and air. At the bottom of the stroke, the piston covers the exhaust port, and the fuel-air mixture is compressed by the rising piston. Just before the piston reaches the top of the cylinder, the spark plug ignites the fuel-air mixture, creating an explosion that drives the piston down the cylinder. During the second stroke, the piston continues to move down the cylinder, pushing the exhaust gases out of the exhaust port. At the bottom of the stroke, the piston uncovers the intake port, and a new fuel-air mixture is drawn into the cylinder. The cycle then repeats itself.