The CRRC 26cc engine has a great reputation for power, a lot of people are using it for 3D in 1/4 scale planes, I'm finishing up a 1/4 scale Yak with that engine in it. Most 1/4 scale planes with that engine are weighing in right around 10 lbs flying weight, and there have been reports of good 3D performance even over 12 lbs.