1. Intake stroke: The piston moves down the cylinder, drawing a mixture of air and fuel into the cylinder through an open intake valve.
2. Compression stroke: The piston moves back up the cylinder, compressing the air-fuel mixture to a high pressure.
3. Combustion stroke: A spark plug ignites the air-fuel mixture, causing it to burn and expand, driving the piston down the cylinder.
4. Exhaust stroke: The piston moves back up the cylinder, expelling the burnt gases through an open exhaust valve.
The four strokes are repeated continuously to produce power. Four-stroke engines are used in a wide range of applications, including automobiles, trucks, boats, and generators.
Here is a more detailed explanation of each stroke:
1. Intake stroke
The intake stroke begins when the piston is at the top of the cylinder and the intake valve is open. As the piston moves down the cylinder, it creates a vacuum that draws a mixture of air and fuel into the cylinder through the intake valve. The intake valve closes as the piston reaches the bottom of the cylinder.
2. Compression stroke
The compression stroke begins as the intake valve closes and the piston starts to move back up the cylinder. The piston compresses the air-fuel mixture to a high pressure. This increases the temperature of the air-fuel mixture, making it more combustible.
3. Combustion stroke
The combustion stroke begins as the spark plug ignites the air-fuel mixture. The burnt gases expand rapidly, driving the piston down the cylinder. This is the power stroke of the engine.
4. Exhaust stroke
The exhaust stroke begins as the piston reaches the bottom of the cylinder and the exhaust valve opens. The piston moves back up the cylinder, expelling the burnt gases through the exhaust valve. The exhaust valve closes as the piston reaches the top of the cylinder.
The four strokes are then repeated continuously to produce power.
