Is a 1/2A size C/L Scale Racer workable?
My answer to this is yes. Keep the model as light as you can get it. Try a Johnson "250" motor. These are cheap and I can get you the links to them if you are inerested. I purchased them for $0.50 each and they will stand 5 amps current. For racing, I would try a GWS 3x3 direct drive prop with as much voltage as required to pull 5 amps. I personally would try to utilize a R/C 5 amp electronic speed control and one of the timers made by JMP or the one sold by Windy Urtnowski. I think you would have to experiment on what kind of voltage supply you could use. There are NiCd, NiMH, LiIon, and LiPo types. Each has it's advantages and disadvantages. I am sure that could bring a lot of comments pro and con from lots of sources-probably a lot more than you really want to know.
If I were to try this, I think using the various types of thin foam would be the place to experiment until you got some things dialed in. It is cheap and one can whip out a flyable model in nothing flat.
If you are interested, I could send you a couple of different types of Johnson 250's to play with. Let me know.
I am presently flying a Magician .15 with electric. It has 240 sq in of wing, weighs 14 oz, and you can see it in this forum under .15 size stunt
Regards,
Larry Lake
Pahrump, NV