This is a classic inline four-cylinder internal combustion engine, the most common powerplant found in automobiles and motorcycles. It converts the chemical energy of fuel into mechanical motion through controlled combustion and explosion within the cylinders.

1. Key Components and Their Functions ▪ Cylinder and Piston:The colored pistons reciprocate up and down within the cylinders and are the core components of the engine. Combustion occurs directly inside the cylinders. ▪ Crankshaft:Converts the linear motion of the pistons into rotary motion, transmitting power to the flywheel and ultimately driving the wheels. The counterweights on the crankshaft maintain operational balance. ▪ Camshaft and Timing Belt: The timing belt synchronizes the rotation of the crankshaft and camshaft. The cams on the camshaft control the opening and closing of the intake and exhaust valves with precise timing. ▪ Flywheel: Stores rotational kinetic energy, enabling the engine to run smoothly and continuously even when only one cylinder is on its power stroke.
2. The Four-Stroke Cycle of Each Cylinder Each cylinder generates power through four repeating steps: ▪ Intake Stroke:The intake valve opens and the piston moves downward, drawing in a mixture of air and fuel. ▪ Compression Stroke:The piston moves upward, compressing the air-fuel mixture and significantly raising its pressure and temperature. ▪ Power Stroke (Combustion): The spark plug ignites the compressed mixture, producing an explosive combustion. The high-pressure gases drive the piston forcefully downward, rotating the crankshaft. This is the only stroke that produces power. ▪ Exhaust Stroke: The exhaust valve opens and the piston moves upward again, expelling the spent exhaust gases from the cylinder in preparation for the next cycle.
3. Multi-Cylinder Coordination In a four-cylinder engine, the pistons fire in sequence rather than simultaneously. This means there is always one cylinder on its power stroke, delivering smooth and continuous power output.