How a Car Engine Works

A car engine is a complex machine that converts the chemical energy in gasoline into mechanical energy that can be used to power the car. The engine is made up of many different parts, each of which plays a specific role in the overall operation of the engine.

The Four Strokes of the Engine Cycle

The engine cycle is the sequence of events that occur in the engine as it converts gasoline into mechanical energy. The cycle is divided into four strokes: intake, compression, power, and exhaust.

Intake Stroke

During the intake stroke, the intake valve opens and the piston moves down the cylinder. This creates a vacuum in the cylinder, which draws air and fuel into the cylinder from the carburetor or fuel injector.

Compression Stroke

Once the intake valve closes, the piston moves up the cylinder, compressing the air and fuel mixture. This increases the pressure and temperature of the mixture, making it more combustible.

Power Stroke

Just before the piston reaches the top of the cylinder, the spark plug ignites the air and fuel mixture. This creates a controlled explosion that drives the piston down the cylinder. The downward motion of the piston turns the crankshaft, which is connected to the transmission and wheels.

Exhaust Stroke

After the power stroke, the exhaust valve opens and the piston moves up the cylinder, pushing the exhaust gases out of the cylinder and into the exhaust system.

The Valve Train

The valve train is the mechanism that opens and closes the intake and exhaust valves. The valve train is driven by the camshaft, which is connected to the crankshaft. As the crankshaft turns, the camshaft lobes push on the valve lifters, which in turn open and close the valves.

The Fuel System

The fuel system is responsible for delivering gasoline to the engine. The fuel system consists of the fuel tank, fuel pump, fuel filter, and carburetor or fuel injector.

Fuel Tank

The fuel tank is a reservoir that stores the gasoline for the engine. The fuel tank is usually located under the rear of the car.

Fuel Pump

The fuel pump is a device that pumps gasoline from the fuel tank to the carburetor or fuel injector. The fuel pump is usually located near the fuel tank.

Fuel Filter

The fuel filter is a device that removes impurities from the gasoline. The fuel filter is usually located between the fuel pump and the carburetor or fuel injector.

Carburetor or Fuel Injector

The carburetor or fuel injector is a device that atomizes the gasoline and mixes it with air. The carburetor or fuel injector is usually located on top of the engine.

The Ignition System

The ignition system is responsible for creating the spark that ignites the air and fuel mixture in the cylinder. The ignition system consists of the battery, starter, distributor, spark plugs, and ignition coil.

Battery

The battery is a device that stores electrical energy. The battery is used to start the engine and to power the ignition system.

Starter

The starter is a device that cranks the engine over to start it. The starter is powered by the battery.

Distributor

The distributor is a device that distributes the spark to the spark plugs. The distributor is driven by the camshaft.

Spark Plugs

The spark plugs are devices that create the spark that ignites the air and fuel mixture in the cylinder. The spark plugs are located in the cylinder head.

Ignition Coil

The ignition coil is a device that steps up the voltage from the battery to create the spark. The ignition coil is located near the distributor.

The Cooling System

The cooling system is responsible for keeping the engine from overheating. The cooling system consists of the radiator, water pump, thermostat, and coolant.

Radiator

The radiator is a device that cools the coolant. The radiator is located in the front of the car.

Water Pump

The water pump is a device that circulates the coolant through the engine. The water pump is driven by the camshaft.

Thermostat

The thermostat is a device that controls the flow of coolant through the radiator. The thermostat is located in the engine.

Coolant

The coolant is a liquid that absorbs heat from the engine. The coolant is usually a mixture of water and antifreeze.

The Lubrication System

The lubrication system is responsible for lubricating the moving parts of the engine. The lubrication system consists of the oil pump, oil filter, and oil pan.

Oil Pump

The oil pump is a device that pumps oil through the engine. The oil pump is driven by the camshaft.

Oil Filter

The oil filter is a device that removes impurities from the oil. The oil filter is usually located near the oil pump.

Oil Pan

The oil pan is a reservoir that stores the oil for the engine. The oil pan is usually located under the engine.

Conclusion

The car engine is a complex machine that converts the chemical energy in gasoline into mechanical energy that can be used to power the car. The engine is made up of many different parts, each of which plays a specific role in the overall operation of the engine. By understanding how the engine works, you can better appreciate the engineering marvel that powers your car.