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I¡¯m curious if anyone has gone from a Catto fixed pitch to a Whirlwind ground adjustable. I have a 68x76 Catto now and looking to go to a 70 inch Whirlwind. I¡¯m curious about performance and weight difference. Part of the weight calculation, the spinner I have a back plate, but no front plate. There is a steel rod that goes through the center of my prop that the tip of the spinner bolts to with a singe small hex head.?
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No Data, but I have a Catto and would be interested in hearing your results!
Doug
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Matt-
I have never tried a Catto on the Tailwind. I have a Whirlwind 70" and am generally happy with it. I have the pitch set so it will turn 2750 at cruise. I observe the 2700 limit. The high pitch does compromise the taakeoff and climb performance, especially in the summer heat. At 6000' I am getting 185 kts true at 2650 but I normally run 170 kts true at around 2550 r/m.?
I have a delrin fitting bonded into the nose of the spinner. Front plate bonded into the spinner with a 3/4" hole for the tube. The tube goes thru the front plate and into the nose fitting. Tight fit on both. The fit on the front of the prop hub is not tight, maybe .001 clearance. I intend to do something about that but not a high priority.
For anyone interested I have a spinner dome only same as in the photo of of the Clement "Big Wind". Free to anyone who will pick it up at Watertown.?
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The advantage for the Catto would be the ability to run 2900 r/m for racing. Otherwise I prefer the Whirlwind.?
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Matthew,
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You may want to take a look at this "Alert Service Bulletin" that was just released by Hartzell regarding the Whirlwind ground adjustable props.
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In my experience, if a calibrated torque wrench is not used, cracks may develop.? If torqued properly, no cracks.
Matthew,
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You may want to take a look at this "Alert Service Bulletin" that was just released by Hartzell regarding the Whirlwind ground adjustable props.
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I'm waiting in a RMA to Hartzell right now.? I am doing my condition inspection and 100 hour prop inspection and noticed the latest instructions mention that there is supposed to be a gap between the front and back hub halves.? I don't have any gap 3/4 of the way around the hub once torqued. The blades are tight and have been fine so far.? I talked with tech support and they said I should send my prop and hub in for inspection.? How much gap do any of you with Whirlwind props have?
On Tuesday, April 8, 2025 at 07:28:40 PM CDT, Doug via groups.io <dsteen563@...> wrote:
In my experience, if a calibrated torque wrench is not used, cracks may develop.? If torqued properly, no cracks.
Matthew,
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You may want to take a look at this "Alert Service Bulletin" that was just released by Hartzell regarding the Whirlwind ground adjustable props.
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Jim Clement installed his spinner that way and many people copied him. Fred Weaver had the hex head vibrate out and damaged his Catto?prop at Baraboo before Airventure?
On Wednesday, April 9, 2025, 11:58 AM, Mike Wilson via groups.io <mike_tailwind@...> wrote:
I'm waiting in a RMA to Hartzell right now.? I am doing my condition inspection and 100 hour prop inspection and noticed the latest instructions mention that there is supposed to be a gap between the front and back hub halves.? I don't have any gap 3/4 of the way around the hub once torqued. The blades are tight and have been fine so far.? I talked with tech support and they said I should send my prop and hub in for inspection.? How much gap do any of you with Whirlwind props have?
On Tuesday, April 8, 2025 at 07:28:40 PM CDT, Doug via groups.io <dsteen563@...> wrote:
In my experience, if a calibrated torque wrench is not used, cracks may develop.? If torqued properly, no cracks. Matthew,
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You may want to take a look at this "Alert Service Bulletin" that was just released by Hartzell regarding the Whirlwind ground adjustable props.
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The Clement method is a variant of Wittmans method first used in the 30's. Used on both the midget racers and the V Witt. Front plate and the aft portion of the spinner are permanently attached to the prop. The front portion is removeable from the prop and is attached to the rear portion and has the cone fastener on the front.? I feel that my method takes at least some of the load off the aft spinner plate. The composite front plate bonded to the spinner dome contributes to the stiffness of the dome. My tube is not a perfect fit in the Whirlwind hub. I intend to make a delrin bushing that will be a press fit into the hub and the shortened tube will fit into the bushing.? I believe that some of the Whirlwind spinners use only the back plate. I don't know if Hartzell is making spinners for the Whirlwind props. I have never looked for a gap between the Prop hub halves. I won't be sending my prop to Hartzell anytime in this century. Hartzell is getting $1650.00 for their Plane Power alternator which is a "modified" car alternator that costs around $150.00 new from auto supply. I have one of the car alternators for when(not if but when) my Plane Power dies.
On Wednesday, April 9, 2025 at 11:22:52 AM MST, Brian Alley via groups.io <n320wt@...> wrote:
Jim Clement installed his spinner that way and many people copied him. Fred Weaver had the hex head vibrate out and damaged his Catto?prop at Baraboo before Airventure?
On Wednesday, April 9, 2025, 11:58 AM, Mike Wilson via groups.io <mike_tailwind@...> wrote:
I'm waiting in a RMA to Hartzell right now.? I am doing my condition inspection and 100 hour prop inspection and noticed the latest instructions mention that there is supposed to be a gap between the front and back hub halves.? I don't have any gap 3/4 of the way around the hub once torqued. The blades are tight and have been fine so far.? I talked with tech support and they said I should send my prop and hub in for inspection.? How much gap do any of you with Whirlwind props have?
On Tuesday, April 8, 2025 at 07:28:40 PM CDT, Doug via groups.io <dsteen563@...> wrote:
In my experience, if a calibrated torque wrench is not used, cracks may develop.? If torqued properly, no cracks. Matthew,
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You may want to take a look at this "Alert Service Bulletin" that was just released by Hartzell regarding the Whirlwind ground adjustable props.
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toggle quoted message
Show quoted text
From: [email protected] <[email protected]> On Behalf Of Brian Alley via groups.io
Sent: Wednesday, April 9, 2025 11:21 AM
To: [email protected]
Subject: Re: [TailwindForum] Catto to Whirlwind? Jim Clement installed his spinner that way and many people copied him. Fred Weaver had the hex head vibrate out and damaged his Catto?prop at Baraboo before Airventure?
? On Wednesday, April 9, 2025, 11:58 AM, Mike Wilson via groups.io <mike_tailwind@...> wrote: I'm waiting in a RMA to Hartzell right now.? I am doing my condition inspection and 100 hour prop inspection and noticed the latest instructions mention that there is supposed to be a gap between the front and back hub halves.? I don't have any gap 3/4 of the way around the hub once torqued. The blades are tight and have been fine so far.? I talked with tech support and they said I should send my prop and hub in for inspection.? How much gap do any of you with Whirlwind props have? On Tuesday, April 8, 2025 at 07:28:40 PM CDT, Doug via groups.io <dsteen563@...> wrote: In my experience, if a calibrated torque wrench is not used, cracks may develop.? If torqued properly, no cracks. ? You may want to take a look at this "Alert Service Bulletin" that was just released by Hartzell regarding the Whirlwind ground adjustable props.
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Whirl Wind propeller GA200L-716?
We went from no propeller to a Whirl Wind ground adjustable after much research. ?Most of the research concerning initial operations on fresh built W10¡¯s to flying W10¡¯s needing pitch adjustments. ?
The Whirl Wind ground adjustable weighs 18 lbs. the 12 ¡°spinner weighs 1 lb. and spacers of variable lengths weigh their actual weight.
The Whirl Wind Propeller Installation and Operation Instructions are very detailed to include Inspections, Continued Airworthiness Requirements, Best Practices and Lycoming Series Propeller Data sheet.
The build quality of all the parts is airworthy quality by our inspection. ?We feel very confident in our decision, that we chose the safest and most practical propeller to fly behind. ?Very anxious to do so too.
Here is a fact to note when replacing propellers on custom build experimental aircraft. ?The Whirl Wind 12¡± ?2B Spinner back plate flange is .80¡± deep from the aft mount plate, that contacts the prop spacer, to the flange aft edge. ?This is the flange where the spinner nutplates are riveted on. ?This is deeper that other spinner back plates. ?Some are barely .50¡± deep. ? To go from a X brand spinner propeller combination that is close to the front of the cowling to a Whirl Wind spinner propeller combination will require cowling adjustment.
Our observation is that this .80¡± spinner flange contact is a very robust spinner installation.
Note: we have reviewed the Alert Service Bulletin.
Attached are photos of the parts.
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What is the ¡°tube¡± you¡¯re referring to?
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On mine a 3/4" x .035 4130 tube. On the wood prop it was a tight fit in the hole in the prop hub. Whirlwind also has a 3/4 hole but the tube is not a tight fit. Lots of options on keeping the front fitting tight. Easiest might be a AN490 rod end welded to the tube with a lock nut. Wittman used a short steel cone and I think he used a plain nut with a jam nut.
Regarding possible cracks in the Whirlwind hub:
I tightened the bolts finger tight and measured the distance between hub halves. Adjusted bolts so that the parts were exactly parallel. Then? tightened bolts 1/4 turn at a time in a cross pattern. When the got reasonably tight I switched to a torque wrench and torqued the bolts a few # at a time. I think I used two torque wrenches to avoid changing sockets and settings for two different size bolts.?
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As I torque mine I use feeler gauges to ensure even gap. By the time it¡¯s fully torqued the gap in some places is less than my thinnest feeler gauge (0.0025¡± IIRC).
On Wed, Apr 9, 2025 at 10:58?AM Mike Wilson via <mike_tailwind= [email protected]> wrote:
I'm waiting in a RMA to Hartzell right now.? I am doing my condition inspection and 100 hour prop inspection and noticed the latest instructions mention that there is supposed to be a gap between the front and back hub halves.? I don't have any gap 3/4 of the way around the hub once torqued. The blades are tight and have been fine so far.? I talked with tech support and they said I should send my prop and hub in for inspection.? How much gap do any of you with Whirlwind props have?
On Tuesday, April 8, 2025 at 07:28:40 PM CDT, Doug via <dsteen563= [email protected]> wrote:
In my experience, if a calibrated torque wrench is not used, cracks may develop.? If torqued properly, no cracks. Matthew,
?
You may want to take a look at this "Alert Service Bulletin" that was just released by Hartzell regarding the Whirlwind ground adjustable props.
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Bob Wray
N115WT
KABI
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FWIW, I have a Catto 66 X 80 on my 180 hp tailwind and really like it except I need another inch or two of pitch, I get 2330 static and about 2530 at 120mph climb speed (at 5000¡¯ DA) which is great for climb but it will go over 2800 straight and level. I get 176 knots/203 mph true at 11500¡¯ at 6.9 GPH but am turning 2610 rpm at 18.5¡± manifold pressure and 65% power at the those altitudes and TAS. It would really be interesting to try a whirlwind GA to see what it would do! I will probably send the Catto back this winter and have it re-pitched to 82¡±. Right now I still have some throttle left at 12500¡¯ at 2610 rpm but I will probably lose some power up high with more pitch/less rpm.?
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Matthew Lovley
Douglas Palmer
Steven Becker
Bob Wray