I guess so, I'm not into metrics much yet but I can tell you from experience tha 1 ci per 5 lbs of plane is the way to go, for example I am flying a great planes 1/3 scale pitts, I have a zenoah g-62 in it, thats 62cc & 3.8 cubic inch, the plane is weighting in @ 181/2 lbs & it has just the right amount of power, now you can use engines from bme, taurus, zdz, brison & so on which will be a bit lighter & more powerful than the zenoah but you will pay more $$$$, I just happened to have this engine so I used it. By the way I am Gil Breaux from rayne

If you are going to buy a new engine you will find the best price & power with a zdz, you can see them a www.rcshowcase.com