G'Day Doug, The Wyvern's not a bad looking plane (thought I had this conversation some time ago?). As for dual engine, there's a few possibilities... You can drive two props from one engine, using something like a differential to split the directions. This is done with some of those small contra-rotating mini helicopters. The trick is to mount one axle fixed to the airframe, drive the housing around with one prop attached to it and the other prop attached to the other end axle. As for two engines, the side by side, reversed direction idea has been used before and worked. I should note though that the two engines were independent of one another, much easier. A couple of Venezuelans' did this with a Cozy, having two Suzuki Swift engines side by side and cantered like a V-8 to allow the drive shaft to run between them. I have a picture, but don't know how to attach to a 'mail' An article appears in EAA Sport Aircraft, May 1998. I would imagine that using two VW's would be a bit more complicated, trying to get the manifolds and exhausts to integrate, not to mention the cooling? I also feel we need to do more to still appear as ultralights, so having two VW's in a plane (even a two seater) is starting to push the envelope, how about a couple of 750/1000 four cyl bike engines? Oddly enough, using water cooled engines would be more practical than aircooled just for the ease of cooling remotely without having to have a really complicated ducting system. Trying to run a common inlet manifold system would be tricky, but not impossible, with the exhaust facing away from each other, they would stay separated on each side to go out through the scale exhaust. If you could build it down to 95:10 weights (two 337's?) it would be totally legal! Arthur.
