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An O-360 in an experimental super cub: what would be the best prop?

The Kid

FOUNDER
Thompson Falls
In an experimental super cub, with an O 360, what would be the best prop for performance? A toothpick or a Catto or?
 
Hartzell Trailblazer constant speed. Lightweight and would give cruise performance too.
John
 
I spent a summer flying behind a MT constant speed. At most I gained 7 MPH in cruise. There is so much drag on a big tire supercub that the CS prop really does not help much. If you want to go fast....small tires....fairings around the struts......cover the gear legs... etc etc. In my OPINION, the CS prop on a Cub is just not worth it. Furthermore, if you are flying with other Cubs you will be slowing down to stay with them....so again....no real benefit.

If you want "out of the hole" performance a Catto with 84-38 would be one option. A compromise might be 84-42 or 43. Anything more pitch that around 43 or 44 will start to have a pretty dramatic impact on T.O. performance

Hope my "opinion" gives you something to think about

Bill
 
Define "Performance" Climb? Speed?

Fixed props are like golf clubs, one just wont do everything "best". My "Opinion" is that a Catto 86-36 is a great starter prop for "climb" and a Catto 84-44 for cruise. I also have a whirlwind 82" that pretty much lives on the cub unless I am out playing...and yes, My name is Jay and I have a propeller problem.
 
The longest, flattest and lightest you can find. Spend the rest of your money on a Mooney because that’s the only way you’ll ever get anywhere:p
 
i really liked the catto 86/38 on my 0360 cub, short T/O great climb and caused about 95-97mph at 2500rpm which isn't to bad. if your in a cub speed shouldn't be a factor or you bought the wrong plane.
 
Wayne Mackey suggested I try the Whirlwind prop a few years ago on my contraption. I liked it so much....I became a dealer for them.
If ultimate takeoff performance is what your after, get a long flat catto. If better all around performance is what your after, the WW might be for you.
 
I've been using the Whirlwind 200G ground adjustable on mine with excellent results. The ability to change pitch as desired in just a few minutes is a big plus. From screaming out of the hole with a good 1400 fpm rate of climb to a cruise setting giving 120 mph on floats. They also have a constant speed version if you have the capability to install a governor.

The Hartzell trailblazer came out after I bought this prop so I can't compare the two. You can't go wrong with the 200G.

Airmaster is another one to look at: https://www.propellor.com/ It is an electric constant speed. They use the carbon fiber blades from various manufacturers and are developing a constant speed version using the 200G blades to fit on the Lycoming 0-360.
 
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Depends on the mission. How much brush are you going to be cutting, are you going to be slinging a lot of mud into the prop, do you do brake lock takeoff on gravel. If so go with a metal prop. If you are going to be flying long distance it would be nice to change the pitch. Ground adjustable is cheaper.
DENNY
 
Keep in mind that a constant speed prop gives you 2700 RPM on take off, this gives you all the 180hp (in theory) as opposed to the what ever HP at a given RPM a fixed pitch prop gives you. As for speed, its not about speed but efficiency. In Bill's case where he gained 7 MPH in cruise that could equate to a lower gallons per hour fuel burn or if he kept the power up 7 more miles per hour at the same fuel burn, either way, a big miles per gallon increase over his fixed pitch prop.

If you are burning less gas that means you carry less gas for your mission or you extend your range and maybe not needing to carry cans. Also with a constant speed prop, you are able to come up with various power settings that fit your mission. I have been amazed with some of the power setting/fuel flow/MPG combinations I have been able to achieve. Case in point, when I fly my 0-360 powered Husky just out putting around, I fly at an "over square" power setting, say 1,950 RPM and 22 inches of mp. At these power settings I am doing 115 statute miles per hour at 5.5 to 6.0 gallons per hour. That is pretty darn good speed/fuel flow result that only a constant speed prop can give you. If I need to get somewhere quicker I can pus it up and still obtain great miles per gallon results.

Now it does matter if it is a Scout, Husky or Super Cub, if you can vary your cruise power settings like this and get a full 2,700 RPM on take off then I think it is well worth it. MT Ultra or Trailblazer, either prop is great, having flown both I prefer the MT, I think its a bit smoother and performs a tad bit better but that is just me, John may disagree.

Kurt
 
Pawnee prop will be hard to beat. ;) If you manage the CG of the aircraft, the pawnee will outperform any fixed-pitched options.
 
Pawnee prop will be hard to beat. ;) If you manage the CG of the aircraft, the pawnee will outperform any fixed-pitched options.
The harmonics of an 0360 are hard on a pawnee prop, even more so if your exp and add a pmag/emag and high comp pistons. the fail point is about 19"'s from the tip. With in a fraction of a second after you lose that much blade your engine will try to depart the airframe.
 
Whirl Wind Aviation (Ohio) if you want a constant speed, Whirlwind Propellor (California) if you want a lighter weight ground adjustable.

My take on a Cub? Up to 200HP I’d favor a fixed pitch. Over 200HP I want a constant speed.
 
Both my Husky 0360 engines were built up by Lycon, both dynoed at about 220+ HP. Think with the composite constant speed, whether MT or Hartzell there are good advantages to the constant speed. MT has lightweight governor, so if one was using a Pawnee fixed pitch I think the weight difference for the composite constant speed would be a weight loss overall, plus the advantages of constant speed. Unless one just wants low speed performance only, then fixed pitch is the best route.
John
 
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there have been quite a few failures from 0360's and most do fail 19" from the tip, one local fellow here. Brian Sutton at pro pilots i believe has the info your looking for as they did some vibration analysis testing, give him a call. It's one of the reasons the 84" mac for an 0360 is so beefy. The 540 which is what the pawnee prop was built for is counter weighted. Also when you go to a pmag, high comp pistons ect you are again changing the harmonic frequency of the engine. Wood props such as MT's and Catto's are great at absorbing the vibrations but i believe there are cases where the leading edge sheath cracked from the vibration frequencies.
I know lots of people run the pawnee prop on 360's for many hrs without incident, i am just passing on info to help a fellow pilot make an informed decision.
 
we put them on a bunch of planes(till FAA wanted someone to pony up $$$ for more tests)... no issues

heard of MANY 82" borers throwing tips & more... on various engines including O-360

My observation also.

Feds want 'engineering data' on Pawnee props in spite of all the previous installs with all the hours on them. Blade failures are so rare that it doesn't come up in conversations.

Web
 
Do you think a 82" Whirlwind Propellor ground adjustable prop turning at full 2700rpm on takeoff could keep up with a fixed pitch 86x36 Catto ?? For Short takeoff.
 
The 86" Catto interests me. The longer the prop the better for efficiency I understand. But if it's basically a wooden prop, does that mean I would have to re-torque it all the time? I had a Sensenich wooden prop years ago, an 80/40 on an O 320 160 hp cub and it did pretty well but it had to be re-torqued all the time and I took it off. So is the Catto different somehow, I hope?
 
The 86" Catto interests me. The longer the prop the better for efficiency I understand. But if it's basically a wooden prop, does that mean I would have to re-torque it all the time? I had a Sensenich wooden prop years ago, an 80/40 on an O 320 160 hp cub and it did pretty well but it had to be re-torqued all the time and I took it off. So is the Catto different somehow, I hope?

It's been a while I did not remove my spinner. Today I took the time to do it and check my 86'' Catto prop bolts. Torque was right on at 40lbs.
 
I haven’t had any issues with the bolts coming loose. It is less weight (19-20#) than a metal prop and the nickle leading edge will take beating without showing it (in water at least). 82-46 on an O-360 angle valve. Craig is pretty good at estimating what would work best for your setup.
 
Just a heads up, if your building this exp and have a new engine DO NOT try and do the brake in with the catto! find a good course prop for the first bit to seat the rings. in cruise with my 0360 9.5/1 pistons at 2500 rpm i was maybe 55% power.
 
Old thread and I’m sure a prop has been bought, but I’ll throw my two cents as I’ve only used cattos from a c90 to a 360. I’ve tried 8638, 8636, 8635, 8443 & 9032. All on a bone stock 360. Had cylinders ported/polished when zeroed out the engine but did not notice anything really except maybe slight improvement in smoothness. 8635 is a damn good prop. Cruises around 85. They all are good. Most people would be completely fine with 8443 and would cover all bases for the same. 2300rpm once moving. Cruises high 90’s at 2400-2450 on my slow ish big tired cub. Nothing touches the 90” in the grunt department. Nothing. Except possibly the 1A200 at full 90” which I’ve never used. At 32 pitch i cruise 80-82 at 2450. I see 2425 once moving. The 90s profile is different. She narrowed it up compared to the 86’s to get the rpm’s up. Could use an inch coarser would be perfect but I wanted the absolute best out of the hole prop I could get for my setup. But that 8635 is no slouch..long story long. The 8443 and 9032 are what I still have. 8443 for skis and quite a bit of tire work if somewhat light load or just straight lining from pre determined landing spots. Heavy or working the rough short stuff..90”. Low 80’s cruise sucks. But as said by others I didn’t buy a cub with 100+ mph cruise speeds in mind. 9034/5 with 10:1’s would turn heads. I’ve wanted to try the 8438 but playing musical props has ran it’s coarse…
 
Catto told me that for a short take off the longer props are better and that's what I have understood all these years as they are more efficient. BUT Catto said that the longer props, like an 86, don't have the rate of climb that a shorter prop would. I find that hard to believe but is it true?
 
IMO a few variables there. But I would say that is definitely not the case that a shorter prop climbs better than a longer. They all climb well. Unless pitched really coarse. Or so flat that they are just beating air. Obviously 8635 and 9032 are very long and flat props, but like I said the 8443 does decent across the board but there’s no comparison in takeoff or climb compared to the other two. Really yank on it in a hard climb with a coarser prop that isn’t giving you optimal rpm already and it just doesn’t have the umph to keep you climbing hard compared to something cranking more. How hard does one need to climb? How long does one need to climb that hard? No complaints at all in the climb department but I want to get off the ground before the log, tree or rock before I worry about how quick I can climb to 2000’ (example). First 10-15 secs is most important to me. That’s just me
 
On an 0-320 and 340 I’ve seen two Catto 84/37 and one worked really well, and the other didn’t turn up much more than 2300rpm

The sensnich ground adjustable seems to work really well, and you only have to buy one prop to get the pitch you want


Sent from my iPhone using Tapatalk
 
IMO a few variables there. But I would say that is definitely not the case that a shorter prop climbs better than a longer. They all climb well. Unless pitched really coarse. Or so flat that they are just beating air. Obviously 8635 and 9032 are very long and flat props, but like I said the 8443 does decent across the board but there’s no comparison in takeoff or climb compared to the other two. Really yank on it in a hard climb with a coarser prop that isn’t giving you optimal rpm already and it just doesn’t have the umph to keep you climbing hard compared to something cranking more. How hard does one need to climb? How long does one need to climb that hard? No complaints at all in the climb department but I want to get off the ground before the log, tree or rock before I worry about how quick I can climb to 2000’ (example). First 10-15 secs is most important to me. That’s just me


It is absolutely true -- the shorter props at a coarser pitch will allow for more pitch pulling the same RPM and make a cub climb better.

They are more efficient at best climb speed--simple. Often enough the loss on the lower end is less than one would expect.

MR Cato knows what he is talking about all our testing showed the same.

For max static thrust the long blades are where it is at , but that is all they are good for.

Go for the constant speed props if cost is not an issue. Never look back
 
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