Man! That's what I love about the "net," if I'm wrong about something then someone out there will have the info to prove it usually. My humble apologies Colin.
Perhaps you are right about the VW not making enough torque to swing a three blade, as you stated the trikes are using engines making much more torque but I'm sure that's due to the reduction drives and the fact they are spinning there little two stokes at twice the RPM, or more, than our little reliable VW's or Corvair's. But then again we could put reduction drives on our engines and make more torque and even use a metal or composite propeller that could even be adjustable. But weight, costs and complexity are all issues we must weigh in determining what's best for our aircraft, right? So what are you suggesting? Fred Johnson Reno, NV