i have a sig 4-star 40 thats partly built i wonder if that would make a good c/l model
Anything with wings will fly CL. Now IIRC - bash me if I am wrong - but I seem to recall that the 4-Star was NOT a fully symetrical wing. That will then preclude good CL Stunt patterns, If you simply wish to mostly go around in circles, or modify for carrier or such, the 4-Star should definitely be a great SPORT CL flier.
Of course with ample power, and a 4-star wing one could do inverted flight because such was done with RC simply by holding adequate 'down elevator' in the normal down position so as to load the wing into a lifting position while inverted. It can be done!
I have a 4-star 60 with a Magnum .60 that flies inverted very well, yet one has to be holding that down elevator to do as stated above. Now I was always thinking that a "Magnum" was a piece of crap, until I bought this whole unit in a swap shop. This Magnum is an excellent engine. Easy starts, excellent power and runs very well over the entire maneuver spectrum that I can do. I have no doubt that a 4-star 40 would fly very well CL with any .29, .35, .40, or whatever. Do remember that the normal dowel. front and Back-Screw wing attachment is not well designed for side-loads like CL will present. That may take a bit of looking at.