Catto prop question

Jkkinz · #1 03-16-2011, 12:02 PM

During my build I have always expected to use a IO360 180 hp engine with a Catto 3 blade prop on my 7A. I recently fell into a great deal on a IO360 A1A 200 hp engine.
I still like the Catto prop but searches have not found anyone using it on a 200 hp engine. If any of you are using a Catto 3 blade on a 200 hp engine I would like to hear from you on performance etc.

ksauce · #2 03-16-2011, 12:23 PM

Rv8bldr has a catto on a 200hp -8 he built. Here's a post from him about his experience.

pierre smith · #3 03-16-2011, 02:03 PM

...on our -6A and never regretted it.

If I had to do it again, I'd go with the two-blade because the cowl is a bear to get off with a three-blade....the two lower blades get scratched by the lower cowl hinges, even with the slot for the nosegear lengthened to its max.

Craig knows how to pitch the prop for your airplane/engine combo. He'll want to know what your preference is....max speed or a compromise between speed and good climb/ aerobatics.

We wanted max speed and he gave it to us.....better than Van's numbers by a bit!

Best,

rv7boy · #4 03-16-2011, 02:12 PM

Quote:

Originally Posted by pierre smith

..If I had to do it again, I'd go with the two-blade because the cowl is a bear to get off with a three-blade....the two lower blades get scratched by the lower cowl hinges, even with the slot for the nosegear lengthened to its max.

So, Pierre, are you saying that a non-nosegear (RV-6) with a Catto three-blade would not have the problem of scratching the two bottom blades? I realize yours was a -6A but just to clarify, I would like your opinion on the non-nosegear cowl removal with the Catto three-blade prop.

Thanks,

Mel · #5 03-16-2011, 02:16 PM

The tail wheel gear does NOT interfere with lower cowling removal. I have never scratched my 3-blade Catto with the cowling.

LifeofReiley · #6 03-16-2011, 02:26 PM

There is a pattern shown in one of the RVators about 3-4 years ago that shows a cut out procedure in the front bottom cowl where the top overlaps the bottom behind the spinner area that makes removing cowling with a three blade a non-issue on (A) models. When assembled you'll never see it due to the overlap.

rv8bldr · #7 03-16-2011, 02:38 PM

Quote:

Originally Posted by ksauce

Rv8bldr has a catto on a 200hp -8 he built. Here's a post from him about his experience.

Uhhh, yeah, what I said

Still have the Catto prop and still love it. 400+ hours on it now.

rv7boy · #8 03-16-2011, 02:46 PM

Quote:

Originally Posted by Mel

The tail wheel gear does NOT interfere with lower cowling removal. I have never scratched my 3-blade Catto with the cowling.

Thanks, Mel. I thought so, but I wanted to hear it from someone with that combination. I had forgotten about yours being a three-blade.

smokyray · #9 03-20-2011, 09:56 AM

Jim,

I tested the first 2 blade RV designed Catto on my RV-4 in 99'. Over time Craig helped me refine the design and several friends purchased 3 blades for their RV4's. I flew alongside many of them and overall I proved time and again the 2 blade outperformed the 3 blade in every aspect except smoothness. I have recently purchased a new Catto 2 blade for my RVX and will post the test data in comparison with it's current MT 2 blade.

Personally, I would go the 2 blade.

Smokey

Spindrift · #10 03-20-2011, 11:20 AM

Hi Jim,

I had a Catto 3-blade paired with an IO-360 A1A on the RV7 I bought flying last year. Unfortunately, I only flew it for about 25 hours, half of which was flying the plane home from Michigan to Oregon, so I never got a chance to do good testing. Static RPM was low (~2150 if I remember correctly) and take-off performance a bit anemic for an RV, but the consensus from several RV builders was that it had more to do with airflow to the engine intake than the prop. The builder had placed the air filter flush with the sloped cowl versus in the typical horizontal induction location, and the theory is that there wasn't enough pressure. I also discovered recently that the CFM rating for the K&N air filter used was about 1/2 of what is needed for the IO-360. Craig was open to working on adjusting the pitch to help if necessary once I sorted out the air intake.

Sadly, before I could work out the problem, we found metal shavings in the oil at 1st oil change and the plane has been grounded since. Turns out the engine had multiple problems including a cracked crank, so I decided to replace it with a new 180 hp IO-360. Craig re-pitched the prop and added his new nickel leading edges. Hope to be back in the air soon.

Hope your experience with the engine you got a deal on is much better than mine!