A motorcycle engine is considered a closed system.
In engineering and thermodynamics, a closed system refers to a system that does not exchange matter with its surroundings, although it may exchange energy. In the case of a motorcycle engine, it operates within a sealed crankcase, where the fuel-air mixture is combusted to produce power. The engine's combustion chamber, valves, pistons, and other components are enclosed within the engine block, ensuring that the fuel and exhaust gases remain within the system.
The combustion process takes place within the closed system, where the fuel is ignited and converted into expanding gases that drive the pistons. This mechanical energy is then transferred through the crankshaft to the transmission and ultimately to the wheels, propelling the motorcycle forward.
While the engine operates as a closed system, it does exchange energy with its surroundings in the form of heat. The engine dissipates heat through various means such as cooling fins, liquid cooling systems, or oil cooling systems. The heat is transferred to the atmosphere or dissipated through a cooling system, allowing the engine to maintain its operating temperature.
The motorcycle takes in air for combustion, expels exhaust gases, and requires an external fuel supply. It interacts with the environment, the rider, and the road, making it an open system in the broader sense.