Ok so I bought this crankcase a few days ago along with a new cylinder and piston.

 The question I have is that after I put it all together. would I have to oil it in any kind of way before cranking or will the castor from the fuel lube it ok and it will be ok to run without worry of engine lock up or failure?

 I know I will prolly have to acquire a reset tool for the piston as I hear numerous things about new pistons. I prolly could use a piston from a babe bee I have but i would prolly have to reset it aswell I would imagine.

 Sorry Im new at this and it has really got my interest!

Or was it a bad idea getting this crankcase?

Oil the parts as you assemble it.  Then run some rich runs to start break in.   

John,
None of the Cox engines required much in the way of break in. as a kid I used to run them somewhat rich for 30 seconds and then set it at a wet 2 for the rest of the tank. That was the normal break in procedure for most everyone else that I knew. The engines that Cox made had fits far superior to most of what was available in that time.Take 2 easy flights, check for varnish, and then go fly some more. I never had a piston reset tool as a kid,no one else did either and those engines literally had hundreds of flights on them. The biggest 'secret' to long life was cleanliness. Dirt would kill them faster then anything else.
Dennis

If you want, I can send you a piston with the rod sticking out the top, so you won't have to make your own.  Seriously, buy a reset tool as your next purchase.  I am speaking from experience.

The guys have spoken on the oiling as you assemble.  Go to a auto patrs store and buy a bottle of Air Tool oil instead of the after run oil.  it is exactly the same thing and cheaper.  if you want it red, buy the Marvel brand (but NOT Marvel Mystery Oil, it is different).  I use the Campbell-Hausfeld brand.

Mongo