Re: Curious about the engine, :question:
Sounds like a good start for a high rpm engine... short stroke and lots of room for porting. Can you post a pic of the transfers on that jug you got?
If you got a good dremel or one of those mini die grinders Harbor freight has, you can get some extra long rotary files for them at browntool.com or yardstore.com I got one that's like 3" long and it reaches that ridge with ease. You can sometimes get these cheap when they have these "grab bag" sales (yardstore.com) on used 1/8" carbide rotary files, I prefer to buy new, but it takes a LOT to dull a carbide burr so the used ones are almost always as good as new.... they have tons of metal working tools at both sites since they're both aircraft structure tool suppliers. I'm sure you'll find a lot of goodies there even if you don't need rotary files...