I am finishing up the Waco 30 as we sit here. (well I would be if I wasn't in here typing) I used the OS Wankel engine in mine but the plane was designed around the Magnum .30. I am putting HS81's all around for servo's. 5 of 'em 'cause the wings take two. The plane came out very tail heavy with the engine mounted in the stock location so I moved it forward as far as I could and balanced it on the aft CG. The hinges that ship with the kit are very stiff after I glued them in place so I think If I were you I would swap 'em for some after market ones. CA hinges are fine but the ones that come with this kit are the cheap round ones and very stiff. I should get a test flight in on mine thursday (I hope ) Good luck with yours.