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 i ....