See here: http://animagraffs.com/how-a-car-engine-works/
He also has a page on how a handgun (the 1911 .45) works -- even more effective than the car engine one -- and one about cheetahs!
He also has a page on how a handgun (the 1911 .45) works -- even more effective than the car engine one -- and one about cheetahs!