When a driver turns a key in the ignition:
● The car battery powers up sending
● Power to the starter motor, which
● 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 in turn causes the crankshaft to rotate.