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Av8r3400
11-09-2014, 07:08 PM
Is anyone out there using a Prince or Catto prop on their Kitfox?

I've been watching, with great interest, threads on several boards about the Zipper motor mods and the associated use of these high tech fixed pitch props.

I have an IVO UL for my Mangy Fox project and if I use the Zipper kit, this prop is not an option any more as it can't handle more than the stock 80 hp.

Flybyjim
11-09-2014, 09:02 PM
What is a zipper kit?

Av8r3400
11-09-2014, 09:21 PM
The Zipper Kit is featured in the "912 Big Bore (http://www.teamkitfox.com/Forums/showthread.php?t=5301)" thread.

av8rps
11-12-2014, 07:09 PM
Is anyone out there using a Prince or Catto prop on their Kitfox?

I've been watching, with great interest, threads on several boards about the Zipper motor mods and the associated use of these high tech fixed pitch props.

I have an IVO UL for my Mangy Fox project and if I use the Zipper kit, this prop is not an option any more as it can't handle more than the stock 80 hp.

Larry,

You can use that UL prop if you want to. Steve Henry flew his 912ULS Highlander in his videos with the IVO UL IFA prop. He said the only issue was that on initial full throttle application the prop would cavitate a bit before getting a good bite of air, and then it went like hell :) However, he was using the Patriot IVO blade, which has a bit more pitch built into it than the regular UL blade. You might want to verify with IVO what blades you have to make a better determination.

But like you, I too am curious if any Kitfoxers are using the CATTO or Prince prop. I just talked to one of my Highlander buds that uses a Prince 74" and absolutely loves it. Granted, I am more interested in the longer versions (the 80 to 84 inch like Troy Woodland is playing with), but I'm not sure our Kitfoxes would have the ground clearance for those lengths (although they might work on floats...). Plus, while I am sure the long blades would provide us with significantly better climb rates, I am afraid the long blade would kill our top end. But it sure would be interesting to hear from someone that is using one.

Paul

Av8r3400
01-03-2015, 12:29 PM
*Bump*

I'm still watching and waiting to see if there is anyone else out there in Kitfox land using or considering the use of one of these new style fixed pitch composite props on their airplane.

I will be contacting both Catto and Prince shortly as to if they have any recommendations on their products for my plane. I will share any information here and would hope that anyone else considering this will share anything they have as well.

beeryboats
01-03-2015, 03:29 PM
[quote
I have an IVO UL for my Mangy Fox project and if I use the Zipper kit, this prop is not an option any more as it can't handle more than the stock 80 hp.[/quote]

I'm going to be in the market for an IVO UL prop for my 582. If yours would work on my engine, keep me in mind.
Jay

avidflyer
01-03-2015, 03:46 PM
I believe his Mangy fox has a 912 which turns in the opposite direction of the 582. Jim Chuk

I'm going to be in the market for an IVO UL prop for my 582. If yours would work on my engine, keep me in mind.
Jay[/quote]

beeryboats
01-03-2015, 06:10 PM
Oh shoot! Could have been good for both of us. Too bad.
Jay

Av8r3400
01-03-2015, 06:43 PM
Sorry, Beery, Avid is right. It's for a 912 motor.

(It will include the motor and parts to make it electrically ground adjustable. :rolleyes:)

Avidfox
01-22-2015, 05:21 PM
If you want to sell your IVO let me know.
Dave

Av8r3400
01-23-2015, 08:48 PM
Today I did put in calls to Catto and Prince in query to their fixed pitch props.

PapuaPilot
01-25-2015, 11:24 AM
My Catto prop is going to be $2750 plus shipping. It's a two blade with nickel leading edges.

Av8r3400
01-25-2015, 11:24 PM
May I ask what diameter and pitch you are getting?

PapuaPilot
01-26-2015, 07:02 AM
It is 74" x 47" for an IO-240. I asked for a cruise prop, not a climb prop.

av8rps
01-26-2015, 01:59 PM
Larry,

Another prop you might want to look at is the Sensenich 68 inch 3 blade. I personally think it will make an awesome prop for a Kitfox, especially considering that our Kitfoxes don't have a lot of ground clearance. Here's what one of the Highlander guys experienced from switching to a Sensenich 68-69" 3 blade from a Warp 72" 3 blade;

"Hi guys,

I recently upgraded my Highlander from a 72 Warp Drive to a 68 Sensenich. What I noticed was a slight speed increase of about 3-5 mph for the same rpm.

The biggest improvement was for sure the smoothness of this prop. With the Warp Drive my windshield was shaking badly from the turbulence created by this prop. Now I barely notice my windshield shaking with the Sensenich. All in all, I would have liked to get 10 mph more speed obviously, but I'm more than satisfied with the result. Also, don't forget that this prop is much nicer, and most important much lighter than the Warp Drive. So it will save your engine sprag cluth on long term.
...Snip, snip"

Note, this is on a 912uls Highlander, so even though he could have run a longer prop he chose the Sensenich for overall performance. And here is his response after I asked what the shorter prop did to his climb rate;

"Good evening Paul,

To answer your questions, with my Sensenich set up to 5650 rpm WOT at level flight just like my Warp Drive was, I lost about 50-100 fpm. So very negligible. I still climb between 1000 to 1200 fpm at 55 mph depending of the air density.

About my landing gear, I didn't streamline the back of the gear when I covered it. Before covering the gear I was cruising at 101 mph at 5300 rpm with 8.50 tires. Now with the gear covered and ABW 29'' I cruise at 109 mph at the same 5300 rpm. This is an amazing improvement considering that I gained weight from the bigger tires and landing gear. What can I ask more??? I have a faster airplane with more STOL capabilities."

I think the Sensenich with its scimitar shaped blades might be one of the more efficient props for planes like ours that can't run long props due to ground clearance. But it would be interesting to hear more about the Sensenich from other people using it. I've heard it is pretty popular with the Vans RV-12 LSA group, but haven't taken the time to investigate that claim. A few friends of mine are telling me if you have an RV-12 the Sensenich is "the prop to have". Granted, our Kitfoxes are more of a STOL aircraft that any RV-12 will ever be. But I'm guessing that unless you are looking for getting the most STOL out of your plane, the Sensenich just might prove to be a really good compromise for speed and climb.

I would say he for sure has one of the faster Highlanders out there with big wheels and tires on a tall gear.

Paul

http://wingsforum.com/viewtopic.php?f=218&t=23571

Av8r3400
01-26-2015, 06:40 PM
This investigation is meant to gather information to offer an option over the bevy of ground adjustable props on the market. In a receint Kitplanes magazine there was an article on Catto propellers and their technology. They make the argument that many, one size fits all blades, in a ground adjustable prop are often operating Ineffeciently. At a given pitch, set by rpm, can be causing the center of the prop blade to pull well but the tips doing little or nothing, or vise versa. A properly designed fixed pitch prop will use the entire length to generate thrust.

In my particular situation, I have mocked up an 80" diameter prop and still have more than adequate clearance with my custom, longer, Grove gear and 21" tires. Right now both prince and Catto are touting their 76" models for the Highlanders and Rans S7.

I am still waiting call backs to discuss the particulars of a Kitfox design.

av8rps
01-26-2015, 07:57 PM
Yeah, I read that article and that makes a lot of sense. Unfortunately it is always a crap-shoot to get the right pitch and length. But when you do, I agree you are likely to have a better performing prop. I will most definitely keep following this thread.

I am really surprised you have that much ground clearance. That must be one heck of an extended Grove gear. I remember seeing one like that years ago on a model 5 at oshkosh, but hadn't seen one since. So I wasn't aware they were still doing those.

Sounds like you're going to have a really cool model 4 when you get that mangey fox done.

colospace
01-27-2015, 07:13 AM
My understanding, from conversations with the Catto Props folks and Debra McBean at Oshkosh this past year, was that Catto was making some props to provide to John McBean for testing/evaluation. I have not heard how that may be going.

n85ae
02-03-2015, 07:51 AM
On my plane with IO-240B, this is my experience:

I went through several Sensenich props on N85AE and ended up with a 74"
prop (can't recall the exact pitch at the moment). I get just under 2300
rpm static, and the plane accelerates fast and gets off the ground quickly,
in level flight firewalled I can hit VNE (140), and typically throttled back
it pulls the plane along at 120 with no problem at all.

Actually 120 is a very easy speed for the plane, it pulls along nicely with
the 74" and the engine doesn't feel like it's working hard at all. The biggest
problem with 120 or faster, is the plane is light and any and all bumps are
VERY noticeable. It is not an airplane who's design is conducive to speed.

I would say a consideration should be that these planes between 120-140 the
drag ramps up so quickly, that a prop isn't going to make much difference ...
On my plane the idea of climb/cruise prop for these reasons is I think a
bit irrelevant. The drag builds so fast that I think the only real difference
will be felt when you hit the gas for takeoff. After that they are all the
same.

So I'm perfectly happy with the prop I have now. The ONLY problem is I
like flying in the rain on occasion, and it's like a sandblaster on that wood
prop.

A 912, or other engine may be totally different, this is strictly my experience
over ten years flying with my IO-240B.

Jeff

Av8r3400
02-03-2015, 06:39 PM
I have made the decision to go with Prince. Lonnie Prince and I had a long discussion and afterwards we came to the conclusion that the prop will be 78" in diameter x 50" pitch for the speed/STOL conditions I am forecasting, with the engine (105 hp zipper equipped 912 UL) I am using.

I will report on the flight testing as the plane is finished and flown, hopefully by this fall.

cubtractor
02-03-2015, 06:59 PM
I'm anxious to hear the results. I been wanting a Prince for a while now.

av8rps
02-08-2015, 06:54 AM
That sounds really exciting Larry. Congrats. You are gonna have one kickass Model 4 when you are done!

Are you planning to install an airbox on your 912ul 105 Zipper? Just curious as I am absolutely positive we are losing at least 5 hp by not getting cooler air into our carbs.

But I think it's funny...no one ever talks about that? Yet it is probably one of the easiest and least expensive mods we could do to get increased performance, while also providing us with carb heat (which I personally have many times wished I had on mine). But as we both know, making a Rotax airbox fit under the cowl of a model 4 would be nearly impossible. So the airbox I'm thinking about would have to be different than the Rotax airbox.

I've often thought about modifying the old Kitfox manufactured airbox (that mounted to the top front of the engine) so that it had a better way to get more cool air to the carbs (start by getting rid of the filter blocking the air into the box, or at least turn it so it has some ram air effect), so that you gain power rather than lose it. I never tried it, but I think if we could have just flown one of those old airboxes without the air filter, rather thank blocking outside air into the carbs, we'd be ramming air in. That alone would have to make more power in my opinion.

I know the 912 will work ok with just air filters sucking warm air right above the exhaust pipe, tight against the firewall. But most engine people would call that "just plain stupid".

Paul

Av8r3400
02-08-2015, 10:06 AM
Actually, Paul, I removed the "cold air" air box system from my Yellow plane and gained about 250 static rpm. Providing evidence to me, that this system is a power loss rather than gain.

Through the build of this plane, I have gone over the FWF coming up with different plans. At one time I was considering a turbo kit which would have required building an intake plenum to fit the existing engine mount and oil tank. Then I considered building a completely new engine mount which would interface with the proper "horse collar" Rotax engine mount. This would have allowed the use of all of the OEM supplied intake parts.

For the sake of simplicity I went away from all of this in favor of the Zipper system. I can now leave the Kitfox IV FWF in place as supplied. At this point I have no further plan for any "hot rod" power modifications to the engine other than the Zipper.

av8rps
02-09-2015, 03:03 PM
Yeah, I removed that airbox from mine too for the same reasons that everyone that had one said it just robbed power. But I always wondered if anyone tried it without the air filter on it. That air filter had the blunt closed-end pointing directly into the airstream, so it was far from a ram air function.

Unfortunately when I redid my plane I utilized the area where the airbox went for other things so it isn't a real simple thing for me to just bolt it on to try it. But I sure would like to have known.

That's why I ran it by you, figuring it would get your engineering brain going and you'd solve the problem for all of us ;)