Now let’s make the exhaust pipe tiny and so restrictive. The piston pushes out the gas, but where can it go? It can’t all escape in time down the tiny pipe before another exhaust stroke occurs.

Water from the exhaust pipe is usually condensed exhaust gases that form when the car cools down after driving. This is especially noticeable in the fall and winter, particularly if the trip is short.

An curved arrow pointing right. THERMO-X is an Australian company which makes heat-reactive paint. In this video, the paint is applied to the exhaust pipes of a Harley Davidson. When the engine is ...