Hi folks,
I see the RCV .60 4-stroke available with a 2:1 gear ratio built in. Recommended props are 2-blade - 14 x 14, 15 x 12, 16 x 12, 3-blade props 13.4 x 13.5, 15.75 x 13, 4-blade props 13 x 13, 14.5 x 11.
I would think that a 14" or 15" prop on a 3D plane would make hovering easier, but I wonder if P-factor will get out of control on the plane? The longer the prop the bigger the rudder corrections need to be when pitching or yawing, no? I was thinking of this engine for a Sig Somethin' Extra which I recently acquired. What a good flying plane. It has an OS 40SF which is a bit peaky in the torque curve. The RCV .60 is 20.5 oz, the same weight as an OS Surpass .70 4-stroker. Price is about the same as the OS too. Vibration is less, and most importantly the torque is double that of a standard 4-stroke due to the gearing, but max prop rpm is about 6000rpm.
-Tom

I am curious whether it would be a good choice for a scale plane appication like a pt 19 i will call Wildcat fuels tomorrow and ascertain that info . I have heard these motors really sound different than most 4 strokes but i cant answer your question obviously .. Bruce

I had also looked into an RCV engine at one time. I finally decided against it when I determined that I would not be able to get sufficient prop rpm to achieve the thrust I was after. I think that the RCV concept would be very interesting on a scale model that would be flown in a scale like fashion. However, without ever actually seeing or hearing one, my two cents might not be worth a wooden nickel.