A four-stroke gasoline engine completes four strokes during one complete cycle of the piston. These four strokes are:
1. Intake stroke: The piston moves down in the cylinder, creating a vacuum that draws air and fuel into the cylinder through the intake valve.
2. Compression stroke: The piston moves up in the cylinder, compressing the air and fuel mixture.
3. Power stroke: The spark plug ignites the air and fuel mixture, causing it to burn and expand rapidly. This expansion forces the piston down in the cylinder, generating power.
4. Exhaust stroke: The piston moves up in the cylinder, expelling the burnt gases through the exhaust valve.
During each of these four strokes, the crankshaft rotates twice. This means that the crankshaft makes two revolutions during one complete cycle of the piston.
Therefore, Technician A is correct in saying that the Otto cycle gasoline engine has four strokes per cycle, while Technician B is correct in saying that the crankshaft makes two revolutions during one cycle.
