RE: G&P Sales PBY-5A Catalina
Last year about this time I was asking the same question. I really wanted to build a PBY and seriously considered the G&P 81" version. I talked with Bill Price (whom I haven't been able to reach lately) and he mentioned the narrow hull problems of the PBY and recommended the Canadair CL215, also an 81" size. On that advice, I got the Canadair, completed it by eary summer and have had several successful flights.
With respect to the kit ... well, its a builder's kit. Lots of hours and lots of room for innovation. Nonetheless, it came out pretty well and lokks and flies well. Its ended up around 14 lbs, with about 9oz of ballast in the nose. I fly from a lake that's at 6000 ft elevation, and with a wing loading of about 36oz/sq ft, and a lot of water drag, I was concerned about getting airborne. So, I used two Saito 82 4-strokes. Well, when I hit the throttles, I was airborne in about 20 ft and climbing at 45 deg like the proverbial rocket ship. Not too scale, I'd say.
With more judicious throttle application, I got better takeoffs, but its way overpowered. I suspect Saito 65's would have been more than adequate. In level flight, at slow, scale-like speeds, I'm about two clicks off idle. I haven't had enough experience with it yet to have decent landings. Always seem to be too hot and porpoise a lot. But I'm going to enjoy practicing.
Speaking of the Saito's, the 82's are fantastic engines - easy starting, smooth, great idle and most important, ultra-reliabe.
Good Luck, Jack