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RV7A performance with Catto 3Blade

bizpilot

Member
Thinking of using Catto 3 blade with aIO-360-200hp on my RV7A project.
Anybody have some performance numbers like high speed cruise, rate of climb, take off roll performance?
Thanks.
 
Catto

As a Catto prop fan I recommend contacting the team directly and discussing your mission and performance needs directly with them. Fixed pitch composite props are a fantastic choice, but you must decide what performance envelope is most important to you. Climb, cruise, or a combo between the two. I enjoyed a Catto three blade that was optimized for max hp cruise at 8500 feet, and with it running so smooth it was easy to enjoy it at WOT, 2700 RPM on my O-320.

Consider:

Craig Catto will tell you that a fixed pitch prop optimized for your mission will give you the best possible performance in that specific operating envelope.

I will say most of us do not exercise the discipline to achieve the maximum performance takeoff numbers, so compromises with any prop are acceptable.

It would be valuable for you to hear what climb performance numbers are achieved with a prop optimized for cruise performance and vice versa.

In the end it is going to fly and look amazing. I recommend nickel leading edges, they will protect your investment even if you don?t fly in the rain. The prop will be simple to own and maintain, which is a huge plus. They are light weight, so CG considerations should be thought out. Adding a heavy crush plate is an option, but why add more weight than you must?
 
I?m also going with the Catto three blade with NLE on my IO-360/180hp -7 build. I had basically the same prop on my O-320/160hp -4 and I really love it, so I decided to use it in my new -7 build.
 
Talk to Catto

I have the 3 blade Catto on my -7, standard version for the 0-360 180HP. I do not have specific numbers but get about 2250 static (Tulsa at 640 MSL), economy cruise at 165 mph turning around 2350 - 2400 rpm, WOT I can turn 2750 rpm for around 200+ mph.
Climbing out of Tulsa one up I can easily get 1800 fpm.

I can generally stay with my CS -7 buddy except for the braking performance of the CS prop.

For fixed pitch you will not be disappointed with the Catto but they can also optimize for your mission and horsepower so it's worth talking to them.
Figs
 
nice prop...

I bought a flying RV7A 4 years ago.

It has a 3 Blade, No nickel leading edge. 66" diameter 75" pitch IO-360.

Static, I only get around 2200rpm. At 8500 DA I have seen 174kts TAS. Motor gets too hot and drinks too much gas to go that fast. I usually flight plan 160kts TAS on about 8.2gph up high. 10gph down low. Slow down another 5-8kts and save another gallon per hour...

I fly off a grass strip about 1150ft sort of flat and useable. On a standard day at full gross weight I can be off in 800ft or so. Sooner on pavement.

I fly IFR so sometimes rain is an issue and it does erode the leading edge. Bugs on the runway too. I have been putting epoxy resin on the leading edge periodically and it has been a big help. Someday I will send it back to have it reconditioned and try the leading edge tape. When/If I buy a new one, I would get the Nickel Leading Edge.

I love the way the 3 blade looks and it is smooth. It is harder to get the cowling off with the 3 blade.

Because it is so light, CG can be an issue. Only one person on the step at a time. As fuel decreases, the CG moves aft.

Overall I am happy with it. :)
 
-7A performance numbers

I have a -7A with an O-360 and 3-blade Catto prop and ran performance tests in Phase 1 from 8000-12000' DA (home base is 6350'). Plane is unpainted so may get a few more knots when it's slippery. POH is attached, see p. 11. Still need to figure out TO/L numbers.View attachment POH N457GH rev 4.pdf
 
I usually flight plan 160kts TAS on about 8.2gph up high.

Because it is so light, CG can be an issue. Only one person on the step at a time.

Ditto on TAS and fuel burn with my -7A at 2550 RPM above 8500. She'll do 165 KTAS at 2600 RPM and is smooth. I have a 20 lb crush plate on the nose to solve the CG issue but can still only have 1 person on the steps at a time. With the 20 lb plate, I was able to recover 11.5 lbs by replacing the PC-680 with an EarthX battery.
 
Catto

I was just told today by a very experienced pilot/airshow performer that I should consider replacing my Sensenich with a Catto on my O-360 RV-7. The slow development of RPMs on take off was what I was discussing with him.
Then I open VAF and see this revived thread.

Does a 3 blade decrease the CG concerns? I need to look up the weight difference and see where that would leave me for CG. I would get the mid-performer, I would think as I don't have a particular climb or cruise mission.

Thanks,
John
 
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