Thanks guys. The project is turning out to be a lot of fun and the things I'm learning are many. The little flywheel has been in my head for more than a year and I was quite pleased to see it come together just as I'd built it, a hundred times in my mind. I'll probably build more of them for any future projects I take on.
John...
I'm making the assumption that the 90° timing rule that applies to steam engines applies to these as well. I moved the cylinders out to a radius of 7/16 in (.4375) and the same for the valve troughs. This required the cylinders to be lengthened to 1 1/8 (1.125) inch. I've also added length to the pistons so that I could space the flywheel and cylinder bodies out a bit to be a bit more open to the viewer.
The little bugger had me worried yesterday. I made a test assembly with the pistons and the whole thing locked up as tight as Dick's hat band. I mean it was like one solid piece of metal with no movement. I honed and greased up the cylinders last night, after squaring the pistons and when reassembled, I could rotate the cyllinders by hand, while holding them in my hands. I took this as a good indication that it will more than likely run ok, once I get things on the base and aligned as needed. I've got my finger crossed.
Steve