RE: prop on ducted fan?
I have seen props on OS 46VX and they work very well. I turn a prop on my OS .25VF-DF and its a awsome combo. The BVM 91 is a powerfull engine! You might run into the problem of finding a fast 90 size airframe. What airframe were you thinking? I would look for a pattern plane. Not sure where to start with a prop. Sell the BVM to me and buy a Nelson