Algodoo

This scene represents a two different firsts for me. It's the first engine (that I've seen, anyway) that uses lasers to produce the water in the cylinders, and it's also the first engine I've made that actually uses a timing process (other than just using a collide script to create water when the piston hits the back of the cylinder).

EDIT: Changed the propeller to the "gold" material. The added momentum seems to make the engine run smoother.