Internal Combustion Engine

Any engine, either reciprocating or rotary, in which the fuel is consumed in the interior of the engine rather than outside of the engine.

Induction Stroke

The stroke where the fuel-air mixture is drawn into the cylinder.

Compression Stroke

The stroke of the internal Combustion Engine where the piston moves into the cylinder, compressing this fuel-air mixture to high density, pressure and temperature.

Ignition

An electric spark then ignites the mixture and converts it into extremely hot burned gas.

Working Stroke or Power Stroke

The piston stroke during which the combustion gases exert a pressure on the moving piston.

Exhaust Stroke

The piston stroke during which the exhaust gases are expelled from the cylinder ready for the next induction stroke.

Bore and Stroke

The bore and stroke of the piston sets the swept volume. The ratio of bore to stroke is a good indicator of the engine characteristic such as how high it will rev and basic fuel economy. More simply it also defines some of the basic dimensions of the engine such as height and length.

Bore versus stroke for a number of production engines.

See also: Alternator, Ancillaries, Aspin Engine, Cam Follower, Camshaft, Carburetor, Carburetor Choke, Compression Ratio, Connecting Rod, Crankcase, Crankcase Emissions, Crankshaft, Cylinder Head, Diesel Engine, Dipstick, Engine, Engine Excitation Mechanisms, Engine Knock, Engine Oil, Evaporative Emissions, Firing Order, Four-Stroke Engine, Naturally Aspirated, Petrol Engine, Piston, Supercharger, Valves, Valvetrain.