## How Do Petrol Car Engines Work?
A petrol car engine is a complex piece of machinery, but the basic principles of operation are relatively simple. The engine converts the chemical energy stored in petrol into mechanical energy, which is then used to power the car.
The Four-Stroke Cycle
The petrol car engine operates on a four-stroke cycle. The four strokes are:
1. **Intake stroke:** The piston moves down the cylinder, creating a vacuum that draws air and fuel into the cylinder through the intake valve.
2. **Compression stroke:** The piston moves up the cylinder, compressing the air and fuel mixture.
3. **Power stroke:** The spark plug ignites the air and fuel mixture, creating a controlled explosion that drives the piston down the cylinder.
4. **Exhaust stroke:** The piston moves up the cylinder, pushing the exhaust gases out of the cylinder through the exhaust valve.
The Engine Components
The main components of a petrol car engine are:
* **Cylinders:** The cylinders are the chambers in which the pistons move up and down.
* **Pistons:** The pistons are the moving parts that compress the air and fuel mixture and transmit the force of the explosion to the crankshaft.
* **Crankshaft:** The crankshaft is a rotating shaft that converts the reciprocating motion of the pistons into rotational motion.
* **Camshaft:** The camshaft is a rotating shaft that opens and closes the intake and exhaust valves.
* **Valves:** The valves control the flow of air and fuel into and out of the cylinders.
* **Spark plugs:** The spark plugs ignite the air and fuel mixture.
The Fuel System
The fuel system delivers petrol to the engine. The main components of the fuel system are:
* **Fuel tank:** The fuel tank stores the petrol.
* **Fuel pump:** The fuel pump draws petrol from the fuel tank and delivers it to the engine.
* **Fuel filter:** The fuel filter removes impurities from the petrol.
* **Fuel injector:** The fuel injector sprays petrol into the cylinders.
The Ignition System
The ignition system provides the spark that ignites the air and fuel mixture. The main components of the ignition system are:
* **Battery:** The battery stores electrical energy.
* **Ignition coil:** The ignition coil converts the low voltage from the battery into a high voltage that is needed to create a spark.
* **Distributor:** The distributor distributes the high voltage to the spark plugs.
* **Spark plugs:** The spark plugs ignite the air and fuel mixture.
The Cooling System
The cooling system prevents the engine from overheating. The main components of the cooling system are:
* **Radiator:** The radiator is a heat exchanger that cools the coolant.
* **Water pump:** The water pump circulates the coolant through the engine.
* **Thermostat:** The thermostat controls the flow of coolant through the radiator.
The Lubrication System
The lubrication system reduces friction between the moving parts of the engine. The main components of the lubrication system are:
* **Oil pump:** The oil pump circulates oil through the engine.
* **Oil filter:** The oil filter removes impurities from the oil.
The Exhaust System
The exhaust system removes exhaust gases from the engine. The main components of the exhaust system are:
* **Exhaust manifold:** The exhaust manifold collects exhaust gases from the cylinders.
* **Catalytic converter:** The catalytic converter reduces the emissions of harmful pollutants from the exhaust gases.
* **Muffler:** The muffler reduces the noise of the exhaust gases.
