I read post after post on this plane and nobody used a 30cc engine that I found. I have a 35dle in the 150 H9 Mustang and it is great power but this plane is coming in 2 or more pounds heavier and I also want to fly with a 4 blade prop. It also is a bigger body plane and not as stream lined as the mustang. From reports the 55 is perfect for it in length and weight and it fits in the cowl. Over powered yes but that is why the make the left stick!