Welcome to the world of model gas engines! Building a model gas engine will sharpen your skills, improve your patience, and furnish you with many hours of pleasure. Probably the most important thing to remember in building your engine is that the final product depends entirely on you and the work you put into it.

Completion of my first engine took more than 100 hours, spread over 1 1/2 years, and gave me a sense of pride that can only be achieved through one's own effort. From the first minute, my goal was to build the best engine I could, and on completion, have the engine start and run. The satisfaction I felt when my goal was realized was beyond description.

In this instruction booklet, you will be led through a "step-by-step" building process that will produce an engine that you can take pride in. An attempt has been made throughout the plans to explain every phase of the process that would not otherwise be self-explanatory.

Equipment needed to build the engine is an engine lathe (at least 6"), drill press, oxygen acetylene welder, hacksaw, files, taps, dyes, and other hand tools. Other machines that would be helpful, but not a necessity, are a band saw, belt or disk sander, arc welder, and milling machines.

This 1 1/8" bore by 1 1/2" stroke, hit and miss engine is built from scratch. Plate steel, round bar stock, and other readily available materials are needed in the building of this engine. All parts can be manufactured, with the exception of the bolts, springs, spark plug, and needle valve. Other parts for the manufacturing of the engine are available commercially, such as gears, cams, rings.

The flywheels are steel and can have spokes or not. The finished diameter is 5 1/2" by 3/4" wide. The crankshaft is 1/2" diameter and runs in oilite bushings, which are lubricated by grease cups.

The piston measures 1 1/8" in diameter. It is made from aluminum and has 3/32" thick cast iron rings, which are available commercially. The cylinder is made from cast iron, which can be found in old window weights, if other sources turn up empty. The ends are silver-soldered to the ends of the cylinder, and the water jacket is sheet metal and is soft-soldered to end caps. Antifreeze is used for coolant and prevents rusting of the water hopper.

The cylinder head is aluminum or can be made from steel. It has the valve seats machined into the face, no valve seats are used other than the head itself.

The carburetor is of simple design. It is a tube with a cross hole to accomodate a model airplane needle valve. The needle valve has an adjustment on one side and the fuel line is attached to the other end.

The fuel tank is made of round or square tubing that has the ends capped; it sets on the same elevation as the engine.

The engine runs on regular or camp stove gas. The cylinder is lubricated by a drip oiler. The electrical system consists of a 6 or 12 volt battery, automotive coil and condenser.

Good luck and behold the sense of achievement building your model gas engine!