The drawings for this model were done and will be available from Bob Roach of Australia. Bruce Satra from Vernal, UT offers the, cylinder heads, crankcase nose cone, prop hub halves and investment cast steel rockers. All else is cut from solid. 14 cylinders, .875 inch bore, 24mm stroke (15/16 approx). The supercharger is using a modified Cummins diesel blower wheel. The engine is 8" diameter and is 1/6 scale of a P&W R-1830 engine as used in the DC-3, B-24's and many other aircraft. It was designed in the early 1930's and during WWII, 173,000 were made .. more than ANY other airplane engine. The builder of this engine is Ron Harris, a gentleman from the UK.