G'day

I have a couple of Cubs - one if which is about the same size as yours. Initially I put an OS 70 Surpass in it and it was fine but really it was quite a bit overpowered and landing was interesting because the big prop still produced quite a lot of thrust even with the engine at idle. I next tried a Supass 40 which flew it ok but was marginally under powered but I suspect very "scale" so I then put in an OS 52 which was just about right. I later took the 52 out for another project and I put in an ASP (same as Magnum) 61 which is what is in it now. The 61 is the same size as the ASP/Magnum 52 but weighs slightly less and is slightly too much but quite OK. The ASP 61 is a very light engine for its capacity.

When I had the 70 in it, people used to say that the model had two modes of flying - Scale Cub mode (about 1/3 power) and Spitfire mode (any more). It was much easier to fly with the smaller lighter engines. The 61 is about the best I had had in it.

I also have a Hanger 9 quarter scale Cub (a wonderful kit to build). It has a Saito 120S in it. It is quite overpowered with this engine and will take off just above idle. On its first flight it actually tried to take off while I was taxiing.

Cubs have lots of wing area. They are floaters. They do not need a lot of power to fly. Of course, a Clipped Wing Cub is intended to be aerobatic and a bit more power will help in one of these. I am building a 1/4 scale SIG Clipped Wing Cub and it will probably have my OS Gemini 160 in it. Total overkill but it should sound nice.

I don't know whether you have flown a Cub before but if not, there are a couple of things to consider. They float, as I have said, and as a result they can be a bit tricky to land if you have too much power and a big prop and your idle is not low enough. Secondly, they have such long wings that they need rudder to be used in turns or they can suffer from "adverse yaw" effects. I have mixed some rudder into my ailerons for the big Cub and that makes landing easier. Differential aileron helps too - lots of up but not much down aileron.

Enjoy your Cubs. I do.

Michael from Oz