G

gmpaul

Active Member
I need some opinions. Just thinking (which usually cost me and gets into trouble) about selling my Catto prop and getting a metal one from Vans. The Catto is a 3 blade for a 0-320 160 hp. 7/16 bolts and has around 12hr. on it. I can not seem to get the RPM up to 2750 it turns close to 2000 at altitude. Instead of me boxing a 3 blade prop up sending back and forth to Catto maybe some one with a stronger motor could use a prop and spinner. On the other hand it sure is a pretty prop I?ll see what ya?ll think.


Thanks : G.P.
 
It would help greatly if you included the diameter and pitch of the prop.
 
gmpaul said:
I need some opinions. Just thinking (which usually cost me and gets into trouble) about selling my Catto prop and getting a metal one from Vans. The Catto is a 3 blade for a 0-320 160 hp. 7/16 bolts and has around 12hr. on it. I can not seem to get the RPM up to 2750 it turns close to 2000 at altitude. Instead of me boxing a 3 blade prop up sending back and forth to Catto maybe some one with a stronger motor could use a prop and spinner. On the other hand it sure is a pretty prop I?ll see what ya?ll think.


Thanks : G.P.
Click to expand...

The metal prop from Van's may not be any different. You say the Catto is a 3 blade for a 0-320 160 hp, is your engine a 0320?

If the Catto is cut for the 0320 there is no way it will turn at just 2000 rpm in flight when attached to a 0320. If it does there is something seriously wrong with the engine. Or the tach reading is in error. What rpm does it turn static on the ground?
 
catto prop

OK here the spec. on the engine

3-bladed wood/glass composite propeller for RV-9
66" diameter X 70 pitch
0-320 160HP@2700RPM
4.375 Finish Propeller Thickness
7" Diameter Prop flange
SAE-2 Pattern, 7/16' Bolts and 5/8' lugs
Thanks for the response G.P.
 
gmpaul said:
OK here the spec. on the engine

3-bladed wood/glass composite propeller for RV-9
66" diameter X 70 pitch
0-320 160HP@2700RPM
4.375 Finish Propeller Thickness
7" Diameter Prop flange
SAE-2 Pattern, 7/16' Bolts and 5/8' lugs
Thanks for the response G.P.
Click to expand...

The 180 HP version is 66" diameter X 74" pitch, except for 1/2" mounting hardware and 74" pitch, it is the same.
 
Hi G.P.
I have a catto 3 blade on my -4 ,Spec 66x72pitch with a O320E2D lyc.
I have no problem running over 2700 rpm's, Is it possible that the timing on the engine is incorrectly?
 
catto 3 blade

If you do considering selling the catto ......I'm interested .....give me a call 620 755 1786
 
Keep Looking!

gmpaul said:
OK here the spec. on the engine

3-bladed wood/glass composite propeller for RV-9
66" diameter X 70 pitch
0-320 160HP@2700RPM
4.375 Finish Propeller Thickness
7" Diameter Prop flange
SAE-2 Pattern, 7/16' Bolts and 5/8' lugs
Thanks for the response G.P.
Click to expand...

If you cannot get more than 2000 RPM in cruise, there is something wrong other than your prop. I would check:
1. Tachometer for accuracy
2. Ignition Timing
3. Carburetor for fuel/air leaks

How many hours on the engine since new or O/H? Has the engine recently been apart? What RPM are you getting on T/O?
Good Luck!
 
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catto prop

Let me see if I can answer some questions
I have not checked static RPM but full throttle gives me 135 kts. Which make me think the tac. is ok.
The timing has been checked along with checking to see if the right gear ring was correct.
70CM6S16-0-16 ? pitch ;)
I still have to eliminate the engine before selling or swapping props.
The engine has 80 hours
A friend called: Said He believes he has located a prop I can borrow to static check the engine. Wow ain't RV'ers GREAT!

Thanks again G.P.
 
gmpaul said:
Let me see if I can answer some questions
I have not checked static RPM but full throttle gives me 135 kts. Which make me think the tac. is ok.
The timing has been checked along with checking to see if the right gear ring was correct.
70CM6S16-0-16 ? pitch ;)
I still have to eliminate the engine before selling or swapping props.
The engine has 80 hours
A friend called: Said He believes he has located a prop I can borrow to static check the engine. Wow ain't RV'ers GREAT!

Thanks again G.P.
Click to expand...

That would be a 79 inch pitch ( sent a pm ).
 
Something is wrong

I can get 2200 static RPM with my 3 blade catto near sea level and have no problem getting to 2700 RPM up to around 10,000+ feet.

FYI: I have a new Catto on order so I can turn 2700 RPM up to about 19,000 DA

Once I fly off the hours on the new one, I might be will to part with the old one. If anyone is interested.
 
Check Tach?

gmpaul said:
Let me see if I can answer some questions
I have not checked static RPM but full throttle gives me 135 kts. Which make me think the tac. is ok.
The timing has been checked along with checking to see if the right gear ring was correct.
70CM6S16-0-16 ? pitch ;)
I still have to eliminate the engine before selling or swapping props.
The engine has 80 hours
A friend called: Said He believes he has located a prop I can borrow to static check the engine. Wow ain't RV'ers GREAT!

Thanks again G.P.
Click to expand...

G.P. I fly out of Houston SW (AXH) and am pretty close to you. I plan to fly to Brazoria tomorrow for food and fuel. I also have one of those neat little portable tachs and would be willing to meet you in Brazoria so that you may use it to check your tach static and in flight. You would find out real quickly if your tach is registering the correct RPM.
 
Steve Brown said:
I can get 2200 static RPM with my 3 blade catto near sea level and have no problem getting to 2700 RPM up to around 10,000+ feet.

FYI: I have a new Catto on order so I can turn 2700 RPM up to about 19,000 DA

Once I fly off the hours on the new one, I might be will to part with the old one. If anyone is interested.
Click to expand...
Steve,

That is going to be one heck of a climb prop!

It sounds to me like you might be RPM limited down low, as I was.

At 10K DA I could only run 64% power on the red line. I never did try it up highter.
 
It will be

N941WR said:
Steve,

That is going to be one heck of a climb prop!

It sounds to me like you might be RPM limited down low, as I was........
Click to expand...

I expect to loose about 5+kts cruise down low because I'm not going over 2700 RPM, but I never use it anyway. I tend to cruise around in the low 150s LOP.

I expect better takeoff & climb, better air braking (unfortunately less glide as well) and gain close to an extra 5+kts up high.

My pitch will be very low, 66. Catto says that the prop should have "negative angle of attack in the transonic range". He is expecting "top speed" at 2700 RPM to be between 156kts and 160kts down low. Up high I'll get less at 2700 RPM.

I took some cruise test data on my current prop so Catto would know where we were starting. Once I get the new one on and tested I'll post the differences.

Unfortunately comparisons of takeoff and climb will be anecdotal since I've never really taken hard data.
 
3-bladed catto wood/composit prop

Greg, I just purchased an RV-7 with O-320/160 HP
Saw your ad on your catto prop and was wondering if it is still available and how much? 434-296-7434 Tim/3-bladed wood/glass composite propeller for RV-9
66" diameter X 70 pitch
0-320 160HP@2700RPM
4.375 Finish Propeller Thickness
7" Diameter Prop flange
SAE-2 Pattern, 7/16' Bolts and 5/8' lugs
Thanks for the response G.P.[/QUOTE]
 
3 bladed prop

Steve, I recently purchased an RV-7 with An O-320- 160 and was wondering if you decided to sell your older Catto 3 blade? 434-296-7434 Tim
 
Catto Prop

I sent my prop back to Catto and he checked it out and even put it on a friend's RV-6. The prop checked out great. This is not what I wanted to hear, meaning I had engine problems. After much fretting, checking, and a few bad words...I don't even know what they mean, I found the problem. It seems that when I had an alternator go out on me a while back it must have spiked my EFIS. All my data stayed in place but my parameters defaulted back to factory settings. There is a lot more to this story but basically there are some problems that are so obvious you can't see them. By the way Catto didn't charge me a dime, even for my mistakes-what a great GUY!

GP
 
As you can see, there are a lot of people willing to take the catto prop.
That says it all.
FYI, My 3-blade is 66x76" pitch. I do struggle to do 2700rpm.
I believe Craig likes to see static+400. (if I remember correctly)
 
Yes, the Catto's have quite a following--and why not--light, smooth, and great performance.

I believe that the static + number that Craig shoots for on his standard props is 500-550. Therefore, if you get 2200 static then you should be able to see 2700-2750 at wot on a fully faired RV with a healthy engine.

BTW, mine is also a 2005 vintage 66x76 (like Dan's) and it will turn a touch over 2800 wot at 8k density. At lift off here in Prescott (elevation 5200ft) I am turning 2220 rpm--have not checked static since moving here but back in San Antonio it was around 2200.

I will be testing the new version Catto 3 blade (with nickel leading edge) against my 2005 vintage 3 blade in the next month or so--results will be posted.

Cheers,

db
 
GEE! We just had the CATTO group at our EAA 292 chapter meeting here in (March 12,2011) Independence oregon. I hear that a video of the meeting might appear on a YOU TUBE segment but Iam not sure when. What I learned was DO keep that prop. Over the two bladed metal ones was my understanding that the three bladed was quiter (vibration too)because of the way the cyclinders fire on the O320 or for that matter a four cyclinder engine. About 5MPH faster than metal at about 7,000 ft. I also felt pretty good about the company on their ability to build props for many apps like the Solar plane that flew to 80,201 feet. NASA project. as well as forumula racers were the props RPMS are WAY ABOVE our RVs. Most all the PITTS downunder have the CATTO blades too. I am now considering the CATTO prop so lets here more from the guys with CATTOs. Are they quiter and smoother? Would like to hear from the CATTO RV gang! OH YEA!! Its was also said that the three bladed acted like a constant speed prop as to drag on final, Pilots like them for the drag on final and flare. Ron 9A
 
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There's very little drag on final..

....Ron. Nowhere near like a CS prop. I flew my Catto 3 blade on my 180 HP -6A for 5 years and 500 hours and absolutely loved it! When we balanced it, it hardly took any weight....it was that close.

What I showed a lot of the guys coming by here for transition training, was to climb at 140 MPH or more, still getting waaaay over 1000 FPM because of more RPM, making more power. We could get 1000 FPM at 160 MPH even....try it...it'll amaze you!

Best,
 
Most of the drag of a windmilling prop is dependent on "disk area". Since the diameter of the Catto 3-blade is less than a 2-blade, the disc area is much less. Therefore a 3-blade F/P has less drag than a 2-blade F/P.
 
I love the look of the 3 blade prop.. We've been trying to decide if we should swap our 2 blade metal prop for a Catto 3-blade..
 
Hi Pierre, thanks for the encouraging words on your Catto prop. I think thats what Iam going to get. Hi Mel, wasn't sure about the CS prop conversation at the club meeting on drag to the 3 blade drag. Would I be right in saying that with 3 bladed Catto windmilling on final would have the the same type of drag by a windmilling 2 blade CS prop? You mentioned disc drag area. So if a 2 blade prop had 72" lenght that would mean theres 36" per blade itself and if we had the Catto 3 blade at a Diameter of 66" then there would be 33" blade lenght times 3 would make 99" in lenght moving air assuming the whole blade moves air at a constant rate ( we know that the blade is not that effective thru out its leading edge, equally.) could we assume more drag in windmilling by the 3 blade than a 2 blade CS or Fixed pitch prop or the larger diameter? I heard in the meeting about the triangle of pushing or gettting the most (Thrust) movement of air from the prop surface. Maybe thats why I see fatter blades and tiny tips. OHH the dynamics of RVing!!!!!! Its fellow RVers like you I look up to! Whole a lot of great info. 38 years of rental aircraft in which I always hoped the prop did what it was suppose to do,move me along for takeoff,PT A to B and then some and landing. So far they have. I always come off the forums a little bit smarter. HEY DOUG thanks for the website!!! Ron 9A
 
ron sterba said:
Hi Mel, wasn't sure about the CS prop conversation at the club meeting on drag to the 3 blade drag. Would I be right in saying that with 3 bladed Catto windmilling on final would have the the same type of drag by a windmilling 2 blade CS prop? Only if both props have the same diameter and blade area. You mentioned disc drag area. So if a 2 blade prop had 72" length that would mean there's 36" per blade itself and if we had the Catto 3 blade at a Diameter of 66" then there would be 33" blade length times 3 would make 99" in length moving air assuming the whole blade moves air at a constant rate ( we know that the blade is not that effective thru out its leading edge, equally.) could we assume more drag in windmilling by the 3 blade than a 2 blade CS or Fixed pitch prop or the larger diameter? No! Number of blades does NOT affect disk area. Disk area is defined by pi X the radius squared.
Click to expand...

Blade area does indeed affect drag, but not nearly as much as disk area. Think about the area of a circle. If you add a small amount to the diameter of a circle, you add significantly to the area. i.e. Most of the area is around the outside edges.
 
FYI - I have a two blade 72" diameter Catto prop and when flying with a friend who has a 72" CS prop on his -7, I still went ripping right past him when he pulled it to idle while flying in formation.

Catto is going send me two new two bladed props for me to test, one will be a 74" diameter. Doing a glide test will be one of the things I'm going to check when they arrive.

A full story on the results should be published in KitPlanes, probably in the fall based on their lead times / publishing schedule.
 
Thanks Mel. I got it!. So I see Pi X radius squared on the Skyhawk blade and the catto you have. quite a difference. Man thanks so much, I guess I can let the hair grow back on the side of my head. Or just maybe its gone forever! A few more questions like this one and trying to find a answer in my tech book 43.13 just might make me bald in no-time!! Thanks again Ron 9a,puttin the tail feathers on this week!!!! just finished the Horizontal Stabilizer.
 
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