Check this out!

[Isphius]

http://www.youtube.com/watch?v=65ig1XH7myw


Its a lego air powered engine. They even sound pretty cool! People have been doing a lot of stuff since i stopped playing with legos... Im now tempted to build an inline 6 verison and a scale model of a mk3!

 

[Topher E]

I'd like to see it tach out.

 

[Isphius]

Here is one at 5000 rpms it even sounds like an I4 revving its pants off...pretty amazing for toys if you ask me. Im gonna build one and power and rc car with it just to see what it can do. Im suprised those cylinders can handle the friction and 5-6 bar of pressure

Edit: if you think about it, these are 1/2 stroke motors. They are powered on the up and down stroke, which would offer pretty amazing power density. And they make maximum torque at very low rpms just like an electric motor. And, they are also powered 360 degrees of rotation for every piston, unlike the typical 120 or so of a 4 stroke. Too bad compressed air isnt a very portable power source

http://www.youtube.com/watch?v=vSZ6rQCHHCw&NR=1