I bought two stuart steam engine castings kits at NAMES a couple years ago. Every so often I get them out and do a little work on them.
I was wondering how much piston/cylinder clearance is required. The bore is 1 inch and the stroke is 1 inch. The cylinder and piston are both cast iron and the piston is suppose to have 1 ring.
Should I stick with the CI ring or change to a teflon ring like PM research uses?
I hope to build a PM Research kit and run them on live steam but I suspect they will run on compressed air most of the time.