Hello; I was thing of building the Balsa USA 1/6 scale Sopwith Pup. I did some research on this plane and seen quite a few flew them on a Saito .52s. I have a Saito .45 Special. From what I understand it is supposed to have a little more power than a standard Saito .45 because of the cam. Do you guys think this .45 Special would be enough power to fly the Sopwith Pup. Would appreciate any comments or ideas. Thanks.

I would suggest sticking with a larger motor. Hopping up a given displacement motor usually brings out the horsepower at higher RPM on the same size prop. Biplanes are draggy and as a rule do better with larger props. A short nosed biplane often will need more nose weight when fitted with a lighter weight engine. I understand wanting to use an engine that you have on hand. The .45 will probably get the Pup off the ground but performance will be sub optimal.

Thanks mgnostic; I looked at the info on the Balsa USA Sopwith and it said " Four stroke--40 - 50" so I was hoping my Saito 45 Special would be enough, but I do have a Tower Hobbies .46 2 stroke I might think about putting that on it. It is supposed to be .1 HP more than the OS Max .46 FX ! Thanks again. George.