The document summarizes the main parts of an internal combustion engine, including the exhaust valve, intake valve, camshaft, cylinder head, spark plug, piston, crankshaft, connecting rod, and flywheel. The exhaust valve allows gases to escape the combustion chamber. The intake valve allows air or air-fuel mixture into the chamber. The camshaft operates the valves via cams. The cylinder head covers and encloses the cylinder, containing cooling fins or water jackets and valves. The spark plug provides ignition when the piston is near top dead center. The crankshaft converts reciprocating motion to rotational motion. The connecting rod transfers force from the piston to the crankshaft. The flywheel