Here are a few animated ones. http://www.keveney.com/Engines.html http://www3.sympatico.ca/watership_down/Animations.htm http://www.geocities.com/Baja/Mesa/7163/gif.html Bob & Sheila Bolhuis RR#4 Aylmer , Ont, Can N5H-2R3 519-765-3337