When I built my -8 a year and half ago I installed a wood sensenich 2-blade prope 71" dia pitched to 83. I really liked the look of the wood prop and was very happy with the performance but happy is a relative term and often elusive so....
Today I installed a new Catto 3-blade 68" dia, pitched 75. I entered myself back into a 5 hour phase 1 test period and am not notifying the FSDO.
Here is a pic:
Several flights were conducted with both props at a Weight/Delta of 1800lbs. The OAT and fuel burn were noted for each data point and the altitude adjusted to account for decrease in weight as the flight progressed - altitude increases with decreasing weight to remain at the same Weight/delta of 1800lbs.
Once the Catto was installed I flew several flights at two differenct Gross Weights with (400lb delta) to highlight the advantage of this test technique. The plots below show an average of 3 runs with the Sensenich, and averages of 3 runs each for the Catto at 1700lbs and 1300lbs. - note the data for the two averaged Catto runs line up nicely. I'll refly this profile at 3 different Weight/Delta Values (2000, 2200, 1500). This will provide a family of 4 level flight curves. Linear regression will allow building actual performance charts at any gross weight and DA from those...
I'll let you guys chew on the data above for awhile...
1 - Catto Prop climb rate was 200 FPM greater than the Sensenich through a 1000ft altitude band, WOT at Vy (110mph), 4000-5000ft AP at 62 deg F at a Gross weight of 1546lbs and was 1306FPM
2 - Sound dramatically decreased (almost eerie)
3 - Vibrations through entire speed sweep were noticeably lower
4 - T/O distance was improved by 200 ft
5 - CHT in climb were significantly cooler (I'm still crunching data on this so no numbers yet)
6 - Cost: Sensenich $1600 + Spinner Kit, Catto - $3000 w/ Spinner Kit
7 - Delivery time: Sensenich: 6wks, Catto almost 12 weeks
8 - The Prop Disk is invisible in flight at RPM above 1400. The sensenich was always visible and distracting.
9 - Installation/Removal of Cowl is much more difficult but doable. I have slightly less than 1/8" gap between cowl and spinner so this is part of it.
9 - My GF says "The plane looks much sexier now!" this is the most important data point of all!!