Some stuff on engines and cycles
How your car works (unless you own a diesel)
Animation of the basic four stroke engine (Otto cycle) and the
entire, very nice article in
How Stuff Works from which it is taken.
More nice articles in Wikipedia: on the
four stroke engine and the
two stroke engine.
The Stirling Engine (beautiful engineering,
the demo in the first day of class).
The Rankine cycle (how electricity is produced in a large power plant):
a toy example seen
in class.