A four-stroke engine is a type of internal combustion engine that operates on a four-step combustion cycle. This cycle consists of four strokes or movements of the piston within a cylinder, which are intake, compression, combustion, and exhaust. The engine is primarily used in vehicles, such as cars, motorcycles, and small aircraft, due to its efficient and reliable nature.
During the first stroke, known as the intake stroke, the piston moves downwards, drawing in a mixture of air and fuel into the combustion chamber through the intake valve. This mixture is then compressed during the second stroke, aptly named the compression stroke, as the piston moves upwards, reducing the volume in the chamber.
The third stroke, called the combustion or power stroke, is where the spark plug ignites the compressed fuel-air mixture, causing it to combust. This explosion generates a force that pushes the piston downwards, converting the chemical energy into mechanical energy. Finally, in the fourth stroke, known as the exhaust stroke, the piston moves upwards again, expelling the burned gases through the exhaust valve.
The beauty of a four-stroke engine lies in its efficiency and power output. By combining these four strokes, it can produce a continuous, powerful rotation of the engine crankshaft. Additionally, due to the cooling and lubrication systems integrated into the engine, it can operate smoothly, ensuring durability and longevity. This type of engine has become the norm in the automotive industry, offering a balance between power, efficiency, and reliability.
