YOUR CAR ENGINE

The process by which a car works is a lot simpler than you may think, the driver turns a key in the ignition

This

Turns the crankshaft

which

Gets the pistons moving

With the pistons moving the engine fires up and ticks over

A fan draws air into the engine via an air filter

The air filter removes dirt and grit from the air

The cleaned air is drawn into a chamber where fuel (petrol or diesel) is added

This fuel-air mix (a vaporised gas) is stored in the chamber

The driver presses the accelerator pedal

The throttle valve is opened

The gas-air mix passes through an intake manifold and is distributed, through intake valves, into the cylinders

The camshaft controls the opening and closing of the valves

The distributor makes the spark plugs spark, which ignites the fuel-air mix

The resulting explosion forces a piston to move down which this in turn causes the crankshaft to rotate

What happens in the cylinders is the magic that gives power and motion to the car wheels

Most car engines use a four-stroke combustion cycle

This cycle starts with piston at the top of the cylinder

Then...

Inside a car cylinder 4 stroke combustion cycle

The intake stroke via the intake valve opens and the piston moves down allowing the fuel-air mix to enter the open space

The compression stroke, the piston moves upwards, this compresses the fuel-air mix by forcing it into a smaller space

Compression makes the fuel-air mix explode with greater force

The power cycle, spark from a spark plug ignites the fuel-air mix, the explosion forces the piston down the cylinder

The exhaust cycle, the exhaust valve opens and the piston moves back to the top of the cylinder which forces the exhaust fumes out

The bottom of each piston is attached to the crankshaft

As the pistons are forced up and down they rotate the crankshaft, which after sending the power through the transmission, turns the wheels

Most cars have at least four cylinders, more powerful cars have more

The harder a driver presses the accelerator pedal the more fuel-air mix is passed into the cylinders and the more power is produced

The 4 stroke cycle repeats itself thousand of times a minute, these repetitions are known as revs

A rev counter tells you how many thousand times per minute the cycle is repeated

The Transmission, controls the power contained in the crankshaft before it goes to the wheels, and allows a driver to control the speed/power of a car by providing different speed/power ratios known as gears

We then have motion and off you go

Other Key Car and Car Engine Components

Alternator, turns mechanical energy into electrical energy to powers a car's electrics, from lights to wipers, it also recharges the car battery

Camshaft, controls the opening and closing of the intake and exhaust valves

Cooling system, car engines produce a lot of heat, this heat needs to be controlled, to do this water is pumped through passages that surround the cylinders and then through the radiators to cool down

Distributor, operates the ignition coil making it spark at exactly the right moment, it also distributes the spark to the right cylinder and at the right time, if the timing is off the engine will not run properly

Exhaust System, once the fuel-air mix has been burnt the remaining gas enters the exhaust system and is expelled from the car, if a catalytic converter is present the exhaust gas passes through it and any unused fuel and other certain chemicals are removed

Head Gasket, the cylinder head (a block that seals all the tops of the cylinders) and the engine block (which contains the main bodies of the cylinders) are separate components that need to fit seamlessly together, the head gasket is a piece of metal that sits between them and connects them

Oil, a car engine consists of many moving parts, oil lubricates these parts and allows them to move smoothly, in most car engines oil is pumped out of the oil pan through a filter that removes any dirt and then is squirted under high pressure onto the bearings and cylinder walls, the oil then trickles down to the sump where the process starts over

Regulator, regulates the amount of energy in the alternator

Timing Belt - a belt connected to both the camshaft and crankshaft ensuring that they work in time with each other