Inline 4 Cylinder Engine

This is an inline 4 cylinder engine that I designed in Autodesk Inventor. With some non 3D print modifications it could make enough compression to run on compressed air like a real 2 stroke engine. As is, printed and put together, the engine can be run by spraying compressed air at the top of the gears and giving it starting spin. Some parts will need to be sanded to fit perfectly and while the crankshaft and piston arms are print in place, the piston head halves will have to be super glued together on the arms. Pen springs can be used as valve springs as long as they're about an inch or more.