The internal combustion engine

Usually when people hear that, they think of a four stroke gasoline engine.

Intake
Compression
Power
Exhaust

The gasoline engine depends on an external source of ignition, so it would actually look more like this:

Intake
Compression
Spark/Power
Exhaust
So it can run in only one direction.


The basic diesel engine only sees the first four.
If your a bored non-rate with a Deuce-and-a-half that knows the above facts, you can make a six-by with one forward speed and five reverse gears.


Just thought you might need to know that if getting over-run by zombies, or something...