Unmachined KitNOTE: Machining & Assembly required. Bore: ⅝" - Stroke: ⅞" - Double Acting This is a ⅛th scale model of an original engine manufactured by the Orr & Sembower Co. of Reading, PA. The original engine was a six horse power, class "F" engine. The original engine we scaled this from came out of a nitroglycerin plant. It was used to mix the acids and glycerin for making nitro. Even after gas engines and electric motors became commonplace, steam engines were considered much more dependable. When mixing, they couldn't stop; for if they did, it was time to run for your life. This makes a beautiful model that you will be proud to own. But please don't make your own nitro plant. Kit complete with bronze and iron castings, all required hardware, gasket material, bar stock and complete working drawings. Cast aluminum base platform.