Just a comment about engine selection on the Contender. I am getting toward the end of my assembly. Wing, tail feathers, control surfaces all done, and down to one of the last steps on the fuse. I am now shaping the built-up cowl. I'm using an OS .61 FX. I haven't tried the balance yet, but I expect to add tail weight if I can't push my 6.0V Ni-Cad back far enough. Balance aside, I had to add a new tool to my workbench in order to fit the engine - a shoehorn!

The .61 is a very tight squeeze. A router bit on the Dremel made short work cowl sides, but I had to take them down to 1/4" or less around the engine mount, and even thinner near the throttle push rod. Maybe once the shaping is done I'll open it up a bit with the Dremel drum sander. I'm not quite sure an engine that's any larger would fit. Even a similar size 4-stroke would be harder because it would have to sit farther out on the mount to account for the rear carb.

Good luck,

Robert