Scrap box “flame licker” vacuum engine

The flywheels are bronze gears with tin rims cast onto the teeth. Cylinder is a cast off from a model engine kit. A ball check valve on the head relieves any pressure as the piston pulls in the alcohol flame. At the bottom of the stroke, the valve on the cylinder closes. The rapidly cooling gasses pull the piston upward for about half of the stroke where the slide valve opens expelling any remains gasses.