I instaled a Magnum 52 4c in my LT40 a few weeks ago. It is converted to a taildragger so the 12x6 prop clearance is not a problem.

I`ve had 3 engines on this trainer. ST GS40 , Evo .46 and the 52 Magnum 4c . The 4 stroke did slow it down , maybe a tad , but I no longer have to do maneuvers at WOT.

The Evo .46 is a power house, turned a 11x6 13.000 rpm`s plus . It was just to much for this type of airframe ,

The SuperTigre GS40 is a sweet little engine , and was a really good fit for this plane. And was an ideal setup when I first started to teach myself to fly.

The Magnum 52 4c has the torque to pull the plane thru Cuban 8`s , Hammerheads , loops, etc. It sips fuel, even WOT and doesnt slime the plane so bad. Only problem I`ve had , is the LS needle turning on it`s own in flight. I silicone it in place and have`nt had a problem since.
The first gallon of fuel thru the Magnum, the power was lacking but once she started to get broke in , the power just keeps getting better. When I switched over to the 4 stroke, I got several comments about how the plane seemed smoother in the air. It does seem to fly better . The little engine has a sweet sound and once set and broke in, has preformed flawlessly.