1. Intake Stroke:
* Purpose: To draw in a mixture of air and fuel (or just air in the case of a diesel engine) into the cylinder.
* How it works: The piston moves downwards, creating a vacuum in the cylinder. This suction draws in the fuel-air mixture through the intake valve, which is open.
2. Compression Stroke:
* Purpose: To compress the fuel-air mixture, increasing its temperature and pressure.
* How it works: The piston moves upwards, compressing the fuel-air mixture. Both intake and exhaust valves are closed.
3. Power Stroke:
* Purpose: To generate power by igniting the compressed fuel-air mixture, causing an explosion.
* How it works: The spark plug (in a gasoline engine) ignites the compressed fuel-air mixture, creating a rapid expansion of hot gases. This expanding gas pushes the piston downwards, converting the chemical energy of the fuel into mechanical energy.
4. Exhaust Stroke:
* Purpose: To expel the burnt gases from the cylinder.
* How it works: The piston moves upwards, forcing the exhaust valve open. This pushes the burnt gases out of the cylinder and into the exhaust system.
The Cycle Repeats:
After the exhaust stroke, the intake valve opens, and the cycle starts again. This continuous cycle of intake, compression, power, and exhaust is what drives the engine.
Key Components:
* Cylinder: The chamber where the combustion takes place.
* Piston: A moving component that travels up and down within the cylinder.
* Connecting Rod: Connects the piston to the crankshaft.
* Crankshaft: A rotating shaft that converts the linear motion of the piston into rotational motion.
* Intake Valve: Controls the flow of fuel-air mixture into the cylinder.
* Exhaust Valve: Controls the flow of burnt gases out of the cylinder.
* Spark Plug: Ignites the fuel-air mixture in gasoline engines.
Types of 4-Cycle Engines:
* Gasoline Engine: Uses a spark plug to ignite the fuel-air mixture.
* Diesel Engine: Compresses the air to a very high temperature, igniting the fuel without a spark plug.
Advantages of 4-Cycle Engines:
* Relatively efficient: They convert a decent amount of fuel energy into mechanical power.
* Reliable: They have a long lifespan with proper maintenance.
* Versatile: Can be used in various applications, from cars to generators.
Disadvantages of 4-Cycle Engines:
* Can be heavier and more complex than 2-cycle engines.
* May have higher emissions than some newer engines.
