I have been flying this plane for about two years with the Zenoah G20 ei installed. If you like scale type flying then the G20ei should fit your needs. In my opinion it needs more engine and I am in the process of doing just that. The engines I have considered are the OS 120AX, Zenoah G26ei, DLE-20 and the DLE-30. I am now leaning toward the OS120AX because of the simplicity of installation. I own each of the other engines so it is not a case of having to buy another engine. I do not fly 3D but I do like large loops and such and the G20 just does not have the power but, it is the smoothest running engine and most reliable engine you can imagine. I also had serious engine overheating problems installing the G20 and cowl exactly as shown in the manual. I had to send my brand new G20 back to Horizon twice for serious overheating repairs. The first time they replaced the engiine and the second time they rebuilt it. I ultimately solved the problem by opening the cowl directly in front of the engine cylinder (fins) and using epoxy to glue lite ply flow directors to channel cooling air directly onto the cylinder cooling fins. Once I did that I had no problems with heating issues again. I use a 17-6 prop and sometimes a 16-8. The engine is usually between 2/3 to full power for the entire flight and I have many, many flights on the plane. It is built like a tank. One last comment, there are very few other planes (ARFs) that get the attention of your fellow modelers as does this one, it is a real looker. Happy flying

Howard