Vintage Four Stroke Petrol Cutaway Engine ModelFour Stroke Petrol Engine Demonstration Model This model displays the internal structure of the engine. The internal surfaces are finished in different colors to show air, fuel and gas mixture and exhaust gas contents. The crank handle can be turned by hand to show the operating cycle with electrical contact for illuminating a 3 volt lamp as a spark plug to simulate ignition. The carburetor is also shown in section. The model is made of cast alloy