If you enjoyed this and you're anywhere near eastern PA, you should consider going to the Model Engineering Expo in York PA. A lot of these guys are retired machinists with their own shops and its amazing what they can do. We used to go every year when I lived in Pittsburgh. Last time I went, there were over 1200 engines in the building, some running on compressed air like this one and many on their own power, steam engines, internal combustion and external combustion. See link for details.
http://www.cabinfeverexpo.com/Here's a few pics from my visits: (I'm kinda of partial to airplane engines, but there's a little bit of everything there)
-RP
Here's a working scale Allison V12


A V8



A double row radial



steam engine
