I was hoping I could get some info on the OS .15 CV-A. I am getting ready to break this engine in. I am using the recommended break-in prop. I wanted to know what the rpm would be for this prop. I am putting this engine on an Ace Ultimate Biplane. Once I get this engine broken in, what prop would you recommend. I am not looking for speed, I am looking for torque. What would you guys recommend for a prop and the max RPM.

Thanks in advance

A good place to start is to look at the manufacterer recommendations for prop sizes. Look in the instruction manual and see what they recommend. Then fly with several props. Find the prop that suits your flying style best.