An engine comprises a tank of compressed air and a piston. The tank of compressed air is connected to a conduit and the conduit is connected to a cylinder comprising a first valve and an inlet to a chamber. The chamber comprises the piston, which reciprocates. The chamber also has a second outlet connected to a second valve. The air traverses from the tank of compressed into the chamber by opening the first valve. Both the first valve and second valve are closed and the compressed air moves the piston in the chamber to produce work. The second valve opens and the air escapes from the chamber and the piston.