Re: Making a custom bike engine
Why not scale back your aspirations to something more realistic, like machining a custom crankcase for building a REAL bicycle motor. Cut yourself a set of cases the allows you to use a real quality crank from a moped or motorcycle combined with one of the hot moped top end assemblies with the single speed manual clutch from the HT.
While building a running 6 cylinder engine from HT's is entirely possible,I would have to say it is very unlikely to succeed as a first machining project during school....
A set of billet custom cases using existing moped and HT parts however would be a great first project involving nearly all aspects of machine work.
Talk to your instructor and see if he agrees with me.
If more is better, then too much is just enough.
If you can't afford it, build it yourself.