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Catto 3-Blade vs Sensenich Wood
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... Other info: 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!! |
Whats the current wait time between date of order and date of delivery for Catto?
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Ken,
Is that white tips? If so, Craig sent you my prop!:rolleyes: I ordered the exact prop 2 weeks ago... Looks great! |
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My Catto 3 blade should be here today
I just checked the fedex tracking and it is due today. I am switching from a metal sensenich to a catto 3 blade, the sensy being a cruise prop, the catto a climb cruise combo, should be interesting.
Randy 8A |
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I ordered mine last November and just received it yesterday! Nearly 4 months!! |
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Couldn't see the color well with the camera angle... yellow tips look great. Congrats on the new prop, Scott |
Flight Test Data
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... Other info: 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!! __________________ |
All I can say is WOW!
Twenty additional mph at the same rpm (2700) on +1 gph in ff----that is a major improvement. You must have a really big grin on your face!! Congratulations and of course, Cheers, db ps. Craig better brace for a surge in orders. |
what did you have
for a static rpm. I just put my catto 3 blade on 68 by 74 pitch, static was 2040, upwind at 115 mph was 2100 rpm, 1500 lbs, top speed was 200 mph at 2550 at 1000' My engine is either not making full power, which I don't think is the case, or my prop is way overpitched.
Randy 8A 0-360 dual bendix mags |
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