Catto prop - 2 or 3 bladed - please help me decide

Hello,

RV7A and IO360 180 hp

I have already decided to buy Catto prop for me project.
Have to decide - 2 or 3 bladed and nickel leading edge option yes or no.

Catto informed me that both 2 or 3 bladed props perform very similar and of course very effective.

I need the plane for long trips but also for a light aerobatic. For sure 68" three bladed prop is better than 72" two bladed on grass or rubble runways because bigger clearance between prop and ground. Yes or not?

Thanks in advance for your input.
Witold

A three bladed prop makes it much harder to remove the lower cowl on an A model. I went with two bladed and love it.

I went with a 74" double. That way I don't give up as much climb performance and it is still easy to remove the cowl.

I am based on a grass strip and haven't picked up anything in a couple hundred hours.

I have a 3blade on my O320 powered 6A. The guy that I took transition training with noticed right away how smooth the prop/engine combo ran. When I built my RV, .016 skins were being used for elevators and rudder, and guys were having issues with them cracking from vibration. So reducing that vibration was one reason I went with the 3 blade. Ground/prop clearance was also a factor, as well as quieter operation.

Then there's the cool factor. Both in sight and sound. Guys on the ground say it sounds awesome.

As to cowl removal, once you get the process down, it's not a game breaker.


Great prop, whichever configuration you go with

Removing any painted cowl on an A model will always be nerve wracking experience best done with 4 hands,masking tape,practice.I've been instructed to never stand the cowl on end always place both half's flat on foam.I went with the three blade,it's a work of art,I'm also an A model,the plan is to cut the slot a little longer.I agree with your choice of a Catto,beyond that it all personal choice. What ever configuration you choose your going to be happy.
RHill

Your biggest issue will be shipping to Poland and the cost. Two blade will be MUCH more cost effective to ship back and forth if you ever need to for adjustment and/or a repair. Three blades are not cheap to ship here in the US. Just another thought direction. With either prop, you will be Happy!

3 blade

Hands down the winner. You look very cool, get all the ramp bunnies....life is better with a three blade.

Just like a nose wheel, its very cool too. Go nose wheel and three blader and you are golden. Is a bit of a pain dropping cowl, ensure you made the extra long cut out bottom and its not that big an issue.

Mine is a straight 7 o-360 and was really leaning towards the 2 blade mostly for price and negligible performance differences. When I asked Craig which prop he would use he said the 3 blade because it smooths out the different power pulses on the 360. For an o-320 he would use a 2 blade.
I went with a 3 blade 68X74, and I do like it.

Like Rick says .... 3 blade!

Looks great, performs flawlessly, smoother, more ground clearance. Like others said, it makes the lower cowl a little more difficult, but by extending the slot a couple inches and exercising a little creativity, you can remove and replace the cowl solo. I have tips on how to do that.

3-Blade!

If you put the tailwheel in the wrong place, that's your problem. Work around it.

In addition to others comments:

A 3 blade will be very noticeably smoother in all operations.
A 3 blade looks better, may climb better, may cruise slightly slower, will make the cowl a little harder to remove / replace.

For the nickel leading edge protection, I would insist on it. Of course I fly in all weather. Without it you will be fine if you avoid flying in any moisture. I have an older catto 3 blade hanging on the wall in my garage that has torn up leading edges from operations in moisture. As little as an hour in mist alone was enough to inflict significant erosion on my old catto prop. We repaired it numerous times before I finally retired it for another prop with leading edge metal.
Now, the big question is can the catto prop retain the leading edge nickel? Seems to me I read of a report(s) of loss of leading edge on these?
I loved the catto prop except for the one deal breaker for me of no metal leading edge. If these newer ones prove to reliably retain the nickel leading edge protection, I would seriously consider a catto for future prop needs.

I will be test flying the New Gen two blade in two weeks. Can't wait to see the numbers. Been flying the Gen Two three blade since Feb 2009 and love it. No speed penalty but have the climb penalty over the two blade. The smooth performance outweighs the climb penalty.

Easy as One, Two, Three...

witek said:

Hello,

RV7A and IO360 180 hp

I have already decided to buy Catto prop for me project.
Have to decide - 2 or 3 bladed and nickel leading edge option yes or no.

Catto informed me that both 2 or 3 bladed props perform very similar and of course very effective.

I need the plane for long trips but also for a light aerobatic. For sure 68" three bladed prop is better than 72" two bladed on grass or rubble runways because bigger clearance between prop and ground. Yes or not?

Thanks in advance for your input.
Witold

Click to expand...

Witold,
As an early Catto customer I have owned Five 2-blade models in the past 17 years. Why?

1. Faster. Earlier model Catto two blades were faster than 3, and it still holds true although not nearly as much.
2. Hand prop starts: Possible with a dead battery. This appeals to me as I travel to some very austere locations...

3. Smoothness? With dynamic balancing I have found the 2 blade equally as smooth as the three.

4. Cost: 2 blade props are cheaper. (and lighter)

You have chosen wisely. I have known Craig for nearly 20 years and put his first RV prop on my RV4.
I still believe in his product...

V/R
Smokey


My (former) RV4 The Bandit in the Idaho Backcountry circa 1998 sporting the first Catto (69X69) 2 blade 150HP RV prop.
Taildraggers have more fun...

3 blade for me.

Thank you all for opinions and suggestions. Still difficult to decide but taking into consideration the difference in price I'm a bit more on the side of 2 bladed.
But for sure 3-bladed is nicer for me

Witold

Yes, the price advantage does go to the 2-blade. It not only comes into the picture for the propeller but if you decide on nickel edges, the 3-blade requires one more (pricing of nickel is per-blade). And, as was already said, shipping is higher for 3-blade propellers.

While I love the look of the 3-blade and I understand the science for why they are smoother, I'm ever so happy with my 2-blade Catto.

Craig does great work no matter which propeller you choose.

Catto Props are like RVs??.

Whichever one you like is best for you!

You can't go wrong with any of them.

2 or 3 blades?

According to the text books, fewer blades are better. From personal experience, my Piper Arrow's prop had tip blade damage, and required replacing them. Long story short, the prop shop made me an offer I could not refuse with a brand new 3 blade conversion. Reluctantly, but realizing the added value. I went for it.
The text books were right on the money. I was never able to reach published top speed, but it was really looked great on the flight line.
My own 7 has two blades.