Based on prototypes built in the early 1900s by the F.S. Snow Engine Co. of Buffalo, NY, this really is a wonderful project if you like making IC engines. In this engine two separate cylinders, in-line, each have a piston with a combustion chamber at each end. The unique feature is that a double acting engine fires on both ends of the piston. The cylinders are 1.06” bore, but the model is nearly 2’ long, and has a 8.5” diameter flywheel. No castings are required, although it might make life easier if you can find a suitable one for the flywheel. 31 pages of drawings, colour photos and building instructions. 13 pages of details of preserved examples.Very well produced softcover. Village Press