I've managed to get my engine to run - how many others have so far? Here is a video of it - the sound and picture quality aren't great but I'll work on those skills later...
[ame]http://youtu.be/WZHkIj9Rhsg[/ame]
It runs but leaks a lot of air past the valve, a little less when the air is admitted through the rear port versus the side port.
I got mine to run after allot of fine tuning. The rotary valve is way to touchy for my liking. I had it too tight when I first put it together - the motor would barely turn over with the valve in place. This is from memory and may be wrong but: I think I lapped the valve on a surface plate but took off a tiny bit too much and it ran but leaked badly - wouldn't self start and the air would run right through the valve / steam chest to the exhaust port without ever going to the cylinders. Then I took off the steam chest and skimmed it by as small a cut as I could take with my baby lathe and tried again, removed then lapped the steam chest until I got it to be just barely too tight to allow for brake in. I may have had to do something about the 3 small 2-56 screws holing the valve plate to the crankcase - I may have lapped the whole thing as an assembly (valve plate and crankcase) to get rid of a couple of high spots, and I may have opened up the countersinks for those 3 screws to let the screw sit down a touch more...
It runs OK now and self starts in forward or reverse most times (except when the video camera is out!) but I think the valve needs a better seal (maybe a groove on the face on both sides for a Teflon o-ring or similar - ie slippery but slightly compliant.) Otherwise I think it needs too much oil for those surfaces to slide and not leak.
I think I will hook up a proper intake and exhaust line to quiet it down some too - its really very quiet without all that air leaking by...
Thanks to everyone on this build - it was fun and a great learning experience.
Mike