I Haven,t seen one fly in person but in the mags, the 26cc size engines worked well.

With the current trend of electrics, they would be out placing the power and turning a 21x12 prop
In the plane..... For my planes I have had, the recommended engines seemed minimal for some of the builds.
Perhaps the were coming out heavy and that was the reason.

This is a 1.60 glow plane (translates to 50cc gas) and will use a engine in that class.
I just hope It was the right choice, and that it will work well.

I have yet to start on mine