Hi All This is my first post and am wondering if you would be interested in my latest model engine. This is of a Rider-ericsson hot air pumping engine. Casting kits are available for this engine in 1", 2", and 3" bore, but I now choose to fabricate from plate, bar stock, and sheet metal. For this model I have worked from the book "Steam and Stirling Engines You Can Build" which details a 2" bore model made from castings, but I have scaled this engine to 1 1/2" bore.