RV-7

Any RV-7 builders out there flying an 0-360 w/fixed pitch 2 blade Catto propeller. I'm ready to order a prop and would like some feedback on customer satisfaction, speed and performance.
Charlie

if you want to fly it soon

then you can forget the catto. i hear he is backed up until we colonize mars,
awesome prop they tell me but the wait is way out there.

cytoxin said:

then you can forget the catto. i hear he is backed up until we colonize mars,
awesome prop they tell me but the wait is way out there.

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At my rate of building, that timetable might work perfectly for me. So is anyone flying with this combo and what do you think?

Thanks! He's about 12 weeks out on delivery. I'm just now starting to mount the engine. My preference is Clark Lydics Performance propellers, however, he's not taking taking orders until Feb 08.

cytoxin said:

then you can forget the catto. i hear he is backed up until we colonize mars,
awesome prop they tell me but the wait is way out there.

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Last time I checked (though it's been a little while) was that his lead time for 3-blade props was HUGE but the 2-blades could be had relatively quickly. Hope that's still true.

I've talked to Craig on the phone SPECIFICALLY about this, and he GARAUNTEES that the three blade will out-perform his two blade in all regimes. I was thinking that a two blade would be better due to reduced drag, but he INSISTS the three blade is superior in every way. The price difference isn't that big...go for the three blade, even though it's a three month wait.

.02

cjensen said:

I've talked to Craig on the phone SPECIFICALLY about this, and he GARAUNTEES that the three blade will out-perform his two blade in all regimes. I was thinking that a two blade would be better due to reduced drag, but he INSISTS the three blade is superior in every way. The price difference isn't that big...go for the three blade, even though it's a three month wait.

.02

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Hi Chad-

Out of curiousity, what does "out-perform" mean here. Are we talking 1-2 knots or is it something significant? I know a three-blade prop will generally climb better, all else equal, but I really don't feel the need to climb faster than the 2K per min. that the 2-blade will give me. Am I going to take a significant performance hit in cruise? (I wouldn't think so, since as I understand it, a 2-blade will generally outperform a 3-blade at the top end. I don't doubt Craig, by any means, just can't believe the difference would be very significant).

I really would prefer going 2-blade because it's $600 less and because I want to retain the possibility of handpropping if I'm stuck somewhere with a weak battery or starter. Just curious what he said here so that I don't have to bug him about the same question.

Thanks.

Man I wish I could answer that. All I got was the three blade would be better. I agree that $600 is a good reason to stick with the two blade, and I'm still very much considering it as well for that reason.

Sorry can't help without another phone call...

Two blade

As someone with 265 hours behind a Catto three blade on a 180, let me just say this. It does everything Craig said it would: betters Van's numbers by several MPH (like 203 TAS MPH @ 2700/8000') and it's really smooth. One problem, since I have an -A is getting the lower cowl off. The downward angled blades make it a tight maneuver. Its rare that it'll climb better than 2000 FPM, usually around 1600-1700 at 140 MPH. There's more ground clearance with the shorter blades but the two blade would definitely be a consideration.

Regards,
Pierre

alpinelakespilot2000 said:

Hi Chad-

Out of curiousity, what does "out-perform" mean here. Are we talking 1-2 knots or is it something significant? I know a three-blade prop will generally climb better, all else equal, but I really don't feel the need to climb faster than the 2K per min. that the 2-blade will give me. Am I going to take a significant performance hit in cruise? (I wouldn't think so, since as I understand it, a 2-blade will generally outperform a 3-blade at the top end. I don't doubt Craig, by any means, just can't believe the difference would be very significant).

I really would prefer going 2-blade because it's $600 less and because I want to retain the possibility of handpropping if I'm stuck somewhere with a weak battery or starter. Just curious what he said here so that I don't have to bug him about the same question.

Thanks.

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Steve,

Back when I ordered my Catto, Craig and I talked at length about the 2 vs. 3 blade thing. Since he custom cuts each blade to match the plane, engine, igintion, and fueling he can beat the published numbers. To answer your question about which is faster, the Catto props (2 or 3 bladed) are turning out to be faster than similar metal props but a 2 blade Catto prop will be faster than a 3 bladed Catto prop.

When I ordered my prop, Craig asked if I was building a -9 or a -9A, what cruise speed I wanted, which engine, HP @ RPM, type of ignition, type of fuel delivery, exhaust, and a few other details. Because of my 135 HP O-290 he advised me against a 3-bladed prop as he felt I didn't have the power for it. However, this is not the case with an O-320.
(I really wanted a 3-bladed prop for the extra ground clearance but with my little engine my 2-bladed prop is still only 68" long, so I'm ok with that.)

From what I have learned from a guy who has a RV-9A with the O-290-D2 like mine, I fully expect a 75% cruise of 175 mph out of my 2-bladed Catto prop.

N941WR said:

When I ordered my prop, Craig asked if I was building a -9 or a -9A, what cruise speed I wanted, which engine, HP @ RPM, type of ignition, type of fuel delivery, exhaust, and a few other details. Because of my 135 HP O-290 he advised me against a 3-bladed prop as he felt I didn't have the power for it. However, this is not the case with an O-320.
(I really wanted a 3-bladed prop for the extra ground clearance but with my little engine my 2-bladed prop is still only 68" long, so I'm ok with that.)

From what I have learned from a guy who has a RV-9A with the O-290-D2 like mine, I fully expect a 75% cruise of 175 mph out of my 2-bladed Catto prop.

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Thanks for adding your experience, Bill.

I'm still kind of hung up on the ability to handprop if necessary because a number of places I like to fly don't have a lot of other planes or services around to provide a jump in the event of a weak battery or starter. I'm not real eager about ever trying to handprop a 3-blader. Do people with 3-blade props never have weak batteries? (Kind of a rhetorical question, but I do wonder what they do when in such a situation.)

I think Mel has pointed out that he uses a 2-blade and has never had an issue with ground clearance or nicks operating off an unpaved strip, so I'm not sure that I need extra ground clearance if getting it comes at other costs.

Looking forward to hearing how your next month or so goes!

Long legs!

Steve,

One other thing we have going for us is the -9 has longer legs than the -7 or -8, which gives us even more ground clearance.

As for the hand prop thing, I'm thinking that isn't going to matter much since I have duel P-mags and don't expect to hand prop it.

Any concern from RV-7 builders about weight and balance issues with a Catto prop? My RV-4 is a little tail heavy with the light Catto on the front. I hear that the RV-7 tends to be a little tail heavy too in anticipation of the heavier engines and props Van anticipated being used. Misinformation?

All,
I talked with Craig yesterday and he told me his 2 blade propeller performs esentially the same as his 3 bladed prop. The difference is smoothness much like a flywheel and harmonic balance on a auto engine. The 3 blade does give the aircraft a fighter appearance and I like it, however at this point by airplane bank account is dwendling and the extra $600 will have to be used for something else. I appreciate everyones input. I'm just surprised that no one using the 0-360 2 blade combination has responded. Craig's back log is 12 week's but that's the maximum. He can actually get them done much sooner if you really need it. He has lots of orders for builders not even close to the prop stage.
Charlie, Tucson, AZ

svanarts said:

Any concern from RV-7 builders about weight and balance issues with a Catto prop? My RV-4 is a little tail heavy with the light Catto on the front. I hear that the RV-7 tends to be a little tail heavy too in anticipation of the heavier engines and props Van anticipated being used. Misinformation?

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There is a local 7A that started life with a wood prop (not Catto) and he was VERY tail heavy. The guy had to put some heavy weight on the starter ring and replace the wood prop with a FP metal one. He did nothing unusual in his build. Typical 7A and very well done at that.

Don't forget with the A's, the mains and steps are all behind the CG adding to the problem. Move everything forward you can.

N941WR said:

There is a local 7A that started life with a wood prop (not Catto) and he was VERY tail heavy. The guy had to put some heavy weight on the starter ring and replace the wood prop with a FP metal one. He did nothing unusual in his build. Typical 7A and very well done at that.

Don't forget with the A's, the mains and steps are all behind the CG adding to the problem. Move everything forward you can.

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Didn't know that about the mains. I'm building a straight 7 so that should mitigate things a little.

Original poster: I really like my O320 / 2-blade Catto prop. I don't think you'll be disappointed either way. I did buy a Landoll harmonic balancer to add smoothness and weight on the nose.