I see no reason why the twins should be a problem. 4 pounds can be balanced with location of the RC gear and batteries. The servo tray can hold the rudder servo only, or rudder and two elevator, it can also be mounted anywhere from the wing support plate to the cockpit (thats about 1 1/2 feet). I am using a 22/6 prop on mine with the ZDZ40 so clearance is not a problem. 40cc is the largest engine I recommend, but I know that won't stop anything. Try to remember the plane flies scale with a 120 four stroke. The firewall is well locked but the plane can pull 15 "G's" think about that with a 5 pound engine, or what will happen to the landing gear on that 4 "G" bounced landing. The power of the engines is not the problem, we can all use our left thumb, the weight can be a problem. If I make the gear soft enough to absorb shock with a saito 150 it will be too soft for a US41, if I stiffen it for the 4.5 pound engine it will transmit too much shock to the airframe and rc gear with the Saito. The wider the range of engines the more difficult it becomes to design, and trust me going from a 120 four stroke to a ZDZ 40 is a WIDE range. we expect them to arrive any day, then I need a week for the instructions.
I do like the Ideas that come out of this kind of post, and I think it's good that I sometimes get to explain what we go through on "this side of the fence", so please keep them coming.
And before you ask AFJ, one more plane before the Buker.
