Here's my PAW .40 in my VK Nieuport. Old plane built about 1970 and originally flown with ST .60, then left in a basement for about 40 years. Guy I bought it from was shocked by how well it flew with the .40 diesel. Prop is a 13x6 which it turned at about 7200 rpm. Plane weighs 5 lbs 6 oz. I went to a lot of trouble to get all weight forward; no ballast needed. Light weight makes for beautiful flights. Jim