What converts piston movement into rotational motion in an engine?

The crankshaft converts piston movement into rotational motion in an engine. As the pistons move up and down due to combustion, they are connected to the crankshaft via connecting rods. The design of the crankshaft allows it to rotate as the pistons move, effectively transforming the linear motion of the pistons into the rotational motion necessary to drive the vehicle's wheels. This rotational motion is critical for the operation of the engine, as it drives the piston motion and powers the engine's output.

The flywheel acts as a stabilizer for the rotational motion produced by the crankshaft, helping to maintain a consistent speed and smooth operation, but it does not convert piston movement itself. The camshaft is responsible for controlling the timing of the opening and closing of the engine's valves and does not play a role in converting piston motion to rotational motion. The ignition coil is responsible for generating the spark needed for combustion, which is again unrelated to the conversion of piston movement.