Engines Engines are found all around our very day lives. They are found in our cars, trucks, vans and motorcycles. Almost all vehicles run on the basic combustion engine. An internal- combustion engine is any type of machine that gets mechanical energy from the expenditure of the chemical energy of fuel burned in a combustion chamber. There are four main types of internal- combustion engines, they are: the Otto - cycle engine, the diesel engine, the rotary engine and the gas turbine. The Otto-cycle engine is usually used in gasoline engines found in cars and airplanes. The diesel engine runs on a differ