I have an OS 70 Surpass in mine, with taildragger configuation. This engine is more than enough power for the plane. I fly off grass as well. This is my second Astro Hog (scratch built). I did move the landing gear block a little bit forward in the wing because the first one was having nose over problems. This plane is designed to fly on the wing and does not need a huge engine to fly well or get it off the grass.