Hi Gents
Only just found this thread
Mike/Jim Your engines look great it always gives me a great buzz when I see one completed and running. I'm extremely pleased that you enjoyed building it.
Jim I like how you've added the valve and governor and piped it for steam have you ever run it on steam ?. I know that one of my grasshoppers has been run on steam successfully but I've never heard of the horizontal being run on steam.
Jason is spot on regarding the use of studs and nut sizes, I just used standard M3 nuts with studs as they are easy to get. When using studs the trick is to get them all the same length the easy way to do this is to assemble the parts with two nuts then file down the stud level with the top nuts, remove the top nut and you've got the same length of stud standing proud making things look nice a neat.
As an aside I'm just completing a book for Crowood press on building this trilogy of engines, hopefully it will be out sometime this year: so keep a look out for it.
Stay Well
Stew