The model represents the internal structure and the operating principle. The internal surfaces finished in different colors to indicate air, fuel and gas mixture, and exhaust gas contents. With cam operated jerk pump and manually operated air inlet diaphragm injection nozzle and starting valve. The firing point of the engine is shown by a 3-volt bulb which glows at the correct point in the cycle by means of an electrical contact system in the model. The model is cast alloy construction, mounted on a strong base. Huge - 16 inch x 7 inch x 6 inch.
Measurements are approximate.