A hole ¹⁄₈″ in diameter should be drilled in the center of each head so as to enable the connecting of the intake pipes. By the use of soft wire solder the heads should be soldered into the ends of the cylinders as shown inFigure 1-d.
The pistons should now be made; for this purpose two additional male ferrules are required. These should be made to operate freely within the cylinders by twisting them in a rag which has been saturated with oil and upon which has been shaken fine powdered emery. When they have been made to operate freely they should be cut down one-half inch from the closed end as shown inFigure 5-a. For the connecting rods, 2 pieces of brass tubing, each ¹⁄₈″ in diameter by 1¹⁄₄″ long, are required, and, as illustrated inFigure 6, should be flattened out at either end and through each end a hole ³⁄₃₂″ in diameter should be drilled. For the connecting of the piston rods to the pistons, studs are required, and these should be cut from a piece of brass rod ¹⁄₄″ in diameter by ¹⁄₂″ in length. As two studs are necessary, onefor each piston, this piece should be cut in half, after which each piece should be filed in at one end deep enough to receive the end of the connecting rod. Before soldering the studs to the heads of the pistons, however, the connecting rods should be joined to the studs by the use of a steel pin which is passed through the stud and connecting rod, after which the ends of the pin are flattened, to keep it in position as shown inFigure 5-a.
For the outside valve mechanism and also to serve in the capacity as a bearing for the crankshaft, a piece of brass tubing ¹⁄₄″ in diameter by 1¹⁄₂″ long is required. Into this should be drilled three holes, each ¹⁄₈″ in diameter, and each ¹⁄₂″ apart as shown inFigure 4. Next, for the valve shaft and also propeller accommodation, secure a piece of ³⁄₁₆″ drill rod 2″ long. On the left hand side of the valve shaft, as shown inFigure 3, a cut ¹⁄₃₂″ deep by ¹⁄₂″ in length is made 1″ from the end. Another cut of the same dimensions is made on the right side only; this cut is made at a distance of ³⁄₈″ from the stud end.
As shown inFigure 1-f, the crank throw consists of a flat piece of steel, ³⁄₃₂″ thick, ³⁄₈″ in length by ¹⁄₄″ in width. At each end of the crank throw a hole ³⁄₁₆″ in diameter should be drilled, the holes to be one-half inch apart. Into one hole a piece of steel drill rod ³⁄₃₂″ in diameter by ¹⁄₄″ long is soldered, to which the connecting rods are mounted, as shown inFigure 1-f. Into the other hole the stud end of the crank throw is soldered.