This is another Stirling hot air engine called a Ringbom. This was "scratch built" (no castings) by a friend of mine who is now deceased, from drawings by Jerry Howell. A small alcohol or propane burner beneath the legs of this engine, turns the flywheel which in turn is belted (belt not installed)to a pump which circulates the water that cools the engine. This needs a nice display board and a little "tweaking" to make it presentable.