I am using a Briggs and Stratton 34cc four stroke gasoline engine, I converted several from Craftsman Weed Trimmers. It is a great plane for the engine. I actually built a mate for the SE5 already, the FunAero Albatros DIII. Good looking plane but not as much fun to fly as the SE5. I started a thread on the DVII build under warbirds and warplanes. Here is a picture of my Warbird fleet this summer. The first two are Balsa USA (Fokker DVIII, and Fokker Eindecker (80"), then the Dynaflite (DuH ) and the FunAero Albatros DIII. It is a 64" wingspan, the same scale as the SE5, flies pretty good, no terrible issues, just a fast flier, the wings are not great for lift but it goes where you point it.

http://www.rcuniverse.com/forum/m_35...tm.htm#3539242