like to put cox engines in guillows models

I have a Guillows Fokker DR-1 kit that I would like to use in C/L.  Can't decide whether to use an .049 or a .020..........

BIG Bear
RNMM/AMM

           I tried it using the .049 Bee and it wasn't successful on the tri-plane. I sheeted my fuse with 1/32" . I'm not sure if this is why it became so tail heavy. I ended up using the anemic OS MAX-S .10 for power and balancing. Ken

                   Bill, the plane was a bit of a handful actually. Even with the Max-.10 the plane was hunting up and down. It wasn't bad enough that it couldn't be flown though. The problems quickly occurred on landing. The gear which was the stock Guillows gear splayed out shattering the small wing in between the wheels. I didn't expect that to last but other problems also happened which was the tail skid which broke. This caused damage to the fuse in the rear. All of this is repairable but it was a quick reminder that these planes are better suited for their original intention which was free flight or rubber power. It's a must to sheet the first few formers at least to the front of the cockpit. Knowing what I know now, this could easily be done. You need to design the plane like a larger model built to accept the punishment. The Tri plane isn't going to stunt and even a large loop was out of the question. It just didn't feel as if it was going to recover and any control input I gave the plane seemed sluggish. It looked great in the air though and that was satisfaction enough for me. I built my tri plane 30 years ago and I've learned a lot since then. I just wanted to see it fly rather than sit on a shelf. I'm happy to say it still resides on the shelf and I don't believe I will try again. Ken