I am preparing to build a Sig 1/4 scale Spacewalker II. I want to use a gas engine and am trying to decide which one. I am considering a Brilelli 26cc but I also have a Homelite 25cc weed eater and a Ryobi 31 cc that I could convert at minimal cost. What sounds like my best option in terms of what will fit best in the plane? Does anyone have any dimensions on the converted ryobi or homelite. I am concerned that it will be too long to fit in the cowl. I also know where I could get a Quadra 35 at a good price. How would that fit? Any help appreciated!

Brian