How Do Diesel Engines Work? - dummies The basic difference between a diesel engine and a gasoline engine is that in a diesel engine, the fuel is sprayed into the combustion chambers through fuel injector nozzles just when the air in each chamber has been placed under such great pressure that it’s hot enough to ignite the fuel spontaneously. Following is a  Labeled diagram of car engine - Carsut The labeled diagram of car engine shared here is one of the best free car engine diagrams you can find. This is because the engine shown in the diagram below is one of the most basic yet simple car engines ever built over the century. It is an Austin 848 cc engine completed with all the important engine parts which make the engine runs.