1/2 Scale Plunket Jr. 4-Cycle Gas Engine

Plunket Jr. is about a 1/2 scale model of the 1/2 H.P. Plunket Jr. engine manufactured by the J.E. Plunket Company of Chicago, Illinois around 1909. It was used to power washing machines, sewing machines and other household chores. It is shown on page 395 of "American Gasoline Engines Since 1872" by C.H. Wendel.

The model is machined mostly from brass bar stock. You will need a 6" lathe and at least a medium size milling machine with a 6" diameter rotary table. Lots of prior shop experience is required. This engine is not for beginners.

The model runs from 350 RPM idle to around 3,000 RPM or so wide open and the sound is really neat with the right exhaust pipe at about 900 RPM.

The plans set consists of 25 sheets of drawings and include a 2-jet throttle carburetor, water pump, fan and radiator core that I designed to cool my engine - you will want to design your own radiator housing, piping and fuel tank. Plus, there are 2 sheets of construction and assembly notes.

Specifications: Flywheel Dia.: 5", Cylinder Bore: 1", Piston Stroke: 1-1/2", Overall Length: 10-1/2"  

Difficulty Level:    Easiest (1...2...3...4...5...6) Hardest