Hi All, I've just finished building the EZ engine. What a great little project. My last project was a bit of a pain and took a long time to do so I was looking for something a bit more straightforward. This certainly fitted the bill. I made it all out of brass except the piston which was phosphor bronze. It will run on very low pressure air - 1.5 psi if my air pressure gauge can be believed. Regards, Alan C.