I have an RCGF 15 in a Graupner 60 size. (How and why I aquired the engine is another matter). Now that it is broken in the power is adequite, but could use more. It was turning a 14-6 MA prop 10,000 rpm. Thought that was too much, probably over 11,000 unloaded in the air so went to 14-8. It turns 8,300 rpm. If I had it to do over, I wouldn't. DLE 20 is about the same weight and only slightly larger dimentions, with goobs more power.