On a high quality and performing unit check out Aero Composites, carbon
fiber props. Only offered with a hydraulic hub when I checked 6 months
ago.

This is the first time I heard MT props are slower. Where did you find
that information?
SeaWinds fly using metal Hartzell or MT,  both with top speeds
approaching 200mph.  I have never heard bad things about the performance
of these props.  Perhaps at higher speeds the effect occurs?


Doug in Japan

My hangar neighbor Tracy Saylor, with the fastest RV6 in the world
at 238 MPH, tried the MT back to back with the metal CS prop he was running.
Lost 15 MPH as I recall. Makes sense when you look at it closely. The
efficiency
of a prop is closely correlated with the thickness of the tips. His theory
was the blade was twisting due to the lower modulus of elasticity of wood
compared to aluminum but I am not so sure. The tips consume most of the HP
as they are going the fastest and account for the majority of the drag. The
MT has rather fat tips out of necessity. If you go to Reno you will find all
the really fast airplanes are using metal props or carbon fiber. The metal
props outnumber the carbon fiber props ten to one. Of course both Hartzel
and McCauley probably put a lot of R&D money into racing props.

Paul Lamar

I wonder how the Hartzell composite props compare speed-wise to their
metal props..

http://www.hartzellprop.com/pressroom/pr_htm/pr_10_22_99.htm

http://www.aero-news.net/news/genav.cfm?ContentBlockID=4db4f126-c8a4-4367-bb97-eda16ff9f345&Dynamic=1


Matt-

"Higher performance - Typically composite blades can not quite match the performance of metal blades, since metal blades can be produced with the thin airfoil sections needed for maximum performance. However, Hartzell says the use of carbon, in combination with Hartzell's specialized manufacturing process, yields a strong, yet thin, monocoque structure that permits the use of thinner airfoil sections at the blade tips and performance comparable to metal."

I rest my case :)

Paul Lamar