The problem is far, far more complicated than just diameter and pitch and it really gets convuluted if you start changing materials.

A propellor is an amazinginly simple wooden club, yes? Well, not even close its a horribly complex intertwining of many different engineering parameters that goes well beyond the two most basics of length and pitch. Just a few of which but certainly not all factors that will have a direct affect also on any combination of airframe engine and propellor are: The structural material and its aerodymamic stiffness (flexing), The infinate variety of airfoils, The blades chord (width), the pitch distribution (The progression of pitch from tip to root), The blades planform (outline shape), The number of blades and on and on and on.

This is the reason The "rules of thumb" and old engine size/propellor charts are not all that accurate and the real solution for any modeler is to slowly develop his own personal "Propwall".

Switch, If I were to respond to your speculation that based just on material that the wooden prop of the same pitch and length would perform better and I really try to avoid responding to stuff like this then I beleve your assumption wound be wrong more often than not. That based on my own assumption that the thinner airfoil in the root regions will be more efficient.

Yup Its a lot of speculation and kinda pointless. Work on your propwall and experiment. Its the only practical way to really know for any given engine /airframe.

John