<human>: Can you explain how a car engine works?
<bot>: An automobile engine is composed of several key parts, including the engine block, cylinder head, pistons, valves, and spark plug. The engine block contains all of the moving parts of the engine, such as the crankshaft, connecting rods, and camshaft. The cylinder head contains the intake and exhaust ports for the cylinders and also serves to direct the fuel-air mixture into each cylinder. Pistons are connected to the crankshaft via the connecting rods, and they move up and down in the cylinders, compressing the air-fuel mixture and causing the explosion that powers the engine. Valves control the flow of gases into and out of each cylinder and the spark plug ignites the compressed air-fuel mixture. This causes the piston to move back down again, which in turn rotates the crankshaft, creating mechanical power that can be used to propel the vehicle.