Engines vs. Motors

http://www.youtube.com/watch?v=FfTX88Sv4I8

http://www.youtube.com/watch?v=XVdZj2EDmhM
with labels

http://www.youtube.com/watch?v=aATDsYVVcRM&feature=fvwrel

http://www.animatedengines.com/otto.html
Otto Cycle

http://auto.howstuffworks.com/engine.htm

Alternate pages for the animation:

http://www.poetv.com/video.php?vid=8037

http://videosift.com/video/Animation-of-car-engine-assembly-and-operation

More info than you need:

http://en.wikipedia.org/wiki/Engine

Motors:

http://www.animations.physics.unsw.edu.au/jw/electricmotors.html