Metal Prop vs. Wood Prop

The right metal propeller will make your plane go faster, climb better, but
just marginally compered to the right wood prop. (with this kind of draggy
planes) if you have a bad choosen propeller on now, you will pick up some
speed to the cost of extra fuel.

Every speed, RPM and power setting have its own optimal propeller diameter,
pitch, blade area.....
The diameter and pitch have the biggest influence on the performance One
inch on the diameter change the RPM as much as 2 inch pitch change.

A Climb prop should not turn faster then the redline with WOT during a climb
(Vy)
A Cruise prop should not turn faster then redline with WOT at your cruise
alt.
A Standard prop fall in between the two above!

A Cub or Champ with a A-65 or C-90 both have a 72"X42" as Standard prop
(wood) (the C-90 will be about 9 MPH faster at cruise, using 30% more fuel)

Jan Carlsson
www.jcpropellerdesign.com


To some extent it is nothing to do with the wood or aluminium that the
prop is made from.
More likely it is the pitch and diameter of the prop you have.

Diameter is set by ground clearance requirements, broadly speaking, so
you can look beyond tinkering there.

Propellor Pitch is what will directly affect the airspeed for any
given engine RPM. (that and the winds)

On the Aluminium props intended for the old Cessna 150 the typical
prop supplied has a 52" pitch.The standard climb prop was 48" pitch
and the standard cruise prop was 54" pitch. (all the same diameter)
You picked the prop to use depending on whether you wanted steep climb
outs, typical around the patch performance, or you were out for long
distance flying.

In your case you really need to find out what props (particularly
their pitch values) were certified for the design. You may actually
have the optimum for your aircraft already and improvements will only
be seen by changing aircraft.

One simple improvement you can make is to clean the prop and give it
some polish. It really is the most critical aerofoil on your aircraft
and should be kept clean and smooth.
My own aircraft had a pretty grotty paint job on the prop when I
bought it, Cleaning this up and getting the surface finish nice and
smooth got me an immediate 4 knots improvement.
In my case the only improvement in cruise speed I can forsee is by
changing to a higher pitched prop.

If you cant garner an improvement buy a better camera and enjoy the
view, either that, or only fly in a tailwind.
Stealth Pilot