Big Bird: Appreciate your advice. I have a lot to learn, and I've been modeling since 1937. You are probably quite correct - that the 26 x 10 would be a better prop selection for the big Cub. I am amazed that the ZDZ80 can do the same job as a normal 5.8 (95 cc) engine. I wouldn't have believed it possible, since it has 15% less displacement than the 5.8 engine, but everybody that owns one only has good things to say about it. That seems to be the least expensive route to get the job done in a satisfactory manner. I have shyed away from the twins because of the cost.

O.K. Here's an update on the Cub. It's completely finished - just waiting for an engine. It is 40% scale, 14.5 ft span, and will weigh in at close to 40 lbs. It is covered with Ceconite, doped, and painted with latex paint. If it flies as good as expected, I will make plans available along with a complete building instruction manual. See photos below.