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Old 05-10-2017, 03:53 PM
gonzaviador gonzaviador is offline
Join Date: Jun 2015
Location: Santiago, Chile
Posts: 6
Question RV-7 and Cato Prop weight advice.

Hi Group. I want to ask some questions related to the Catto prop use in a RV-7 and the effect that it has on the CG, and how to address it. I know that a lot has been written about this issue, so is not my intention to start a new tread on it. My engine will be the Aerosport Power IO-375.

My first choice would be the Aluminum Hartzell, but the only issue that I have with it is, since I'm in Chile, I don't have an authorized Hartzell repair facility here (although there are many maintenance facilities that can do the job), and want to avoid the regular maintenance schedule and costs.

I've read that many of the ones that have used a lightweight prop had cg issues, but other seems to be flying fine with no issues, so I'm a little puzzled.

In short, my questions are:

- There is a way to use a Catto Prop in a RV-7 and don't have CG issues? How? (heavy crush plate, extension, and so on... where do I purchase such items?)
- The use of the Catto will require some kind of mod to the cowls or other part of the airframe?
- Does the prop has a regular inspection schedule? can be performed by yourself or do you need a maintenance facility to do it?
- If little damage occurs (nicks), there are guidelines to verify yourself if it still airworthy? Can this little damages be repaired by yourself?

Thanks a lot for your advice.
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Old 05-11-2017, 10:05 AM
swisseagle's Avatar
swisseagle swisseagle is offline
Join Date: Feb 2005
Location: 20km outside of Zurich, Switzerland
Posts: 410
Default Heavy crush plate ...


My buddy is running a Catto prop with a 14lbs crush plate to keep things aligned. Nicole at Catto organized it from Sabre Manufacturing.

Works fine!

RV-7A, TMX-IO-320, FM-150, Sensenich FP
Flying since 28. April 2016
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Old 05-11-2017, 01:40 PM
climberrn climberrn is offline
Join Date: Oct 2008
Location: Carson City, NV
Posts: 279

Not sure how far along your build you are, but I'd tell vans you have a 0-320 and get the motor mount for that. From what I understand it's an inch longer. Better to push the weight out than add extra weight. Unless your plane is VERY light...

Let us know what you come up with.

RV-7A at CXP
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Old 05-11-2017, 03:41 PM
swisseagle's Avatar
swisseagle swisseagle is offline
Join Date: Feb 2005
Location: 20km outside of Zurich, Switzerland
Posts: 410
Default The engine mount for 320 is longer ...

It is 2" not one!

RV-7A, TMX-IO-320, FM-150, Sensenich FP
Flying since 28. April 2016
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Old 05-12-2017, 09:32 AM
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Raymo Raymo is offline
Join Date: Nov 2014
Location: Richmond Hill, GA (KLHW)
Posts: 1,666
Default Saber Manufacturing

I wasn't aware of another motor mount option and went with a 20 lb Saber plate on the front. Works great and my CG is well within the aft limit with me at 210, a passenger at 190, full fuel and 50 lbs of baggage. With a lighter or no passenger, I can max out the baggage compartment.

Mine is a -7A, which may differ a little.
RV-7A - Slider - N495KL - First flt 27 Jan 17
O-360-A4M w/ Catto 3 blade NLE, AFP FM-150 FI, 1 PMag, Vetterman Trombone Exh, SkyTech starter,
PlanePower Alt, FlightLines Interior, James cowl & plenum
All lines by TSFlightLines

"The object of the game, gentlemen, is not to cheat death: the object is not to let him play."
Patrick Poteen, Sgt. U.S. Army

Last edited by Raymo : 05-15-2017 at 10:20 AM.
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Old 05-13-2017, 11:44 AM
Vansrv7arob Vansrv7arob is offline
Join Date: Dec 2010
Location: Sydney, Australia
Posts: 122

I used the 320 mount, need to order 360 cowels unfortunately you'll have to graft about 1.5 - 2 inches on the cowels to give them enough length, Would I do it again? Maybe... Probably, putting a light weight prop on then bolting 20lb of dead weight behind it, kinda an afterthought.... But that way with the spacer does allow you to more easily convert to a metal CS in the future.

................./ ' \.

M: (61) 401 578 700
Fax (61) 2 9410 1924
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Old 05-13-2017, 04:10 PM
zilik's Avatar
zilik zilik is offline
VAF Moderator
Join Date: Jan 2005
Location: Pine Junction, CO
Posts: 616

Originally Posted by gonzaviador View Post
My engine will be the Aerosport Power IO-375.
In my humble opinion is that an IO-375 would only be happy with a constant speed prop.

Why install a performance engine and derate it with a fixed pitch prop?
Gary "Seismo" Zilik
Pine Junction, Colorado
RV-6A N99PZ S/N 22993
RV-3B Tail, wings and fuselage.
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Old 05-31-2017, 06:19 PM
gonzaviador gonzaviador is offline
Join Date: Jun 2015
Location: Santiago, Chile
Posts: 6
Default Thanks.

Thant you very much for your advices. After doing more research locally, I've decided that going with the Hartzell CS will be the simplest way to go.

Thanks again.
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Old 06-04-2017, 08:16 AM
drainge drainge is offline
Join Date: Jan 2017
Location: Boulder, CO
Posts: 18

I'm flying behind an IO-375 with a catto 3-blade. My plane uses a 14lb crush plate.

WRT "derating" of the engine: the catto is the smoothest prop I've ever used; I'd be tempted to go with it for that reason alone. But beyond that, I just don't see the issues that get talked about endlessly on VAF -- my climb performance is excellent, even at the high elevation of my home field; cruise is very comfortable at 165kts and 60% power; and I have no issues slowing down.

I'm sure I could eek out a bit more with a CS prop, and I do wish I could take advantage of the 3 blade without the heavier crush plate, but as far as the 375/prop combination goes I'm very pleased.

Did I mention the looks? It looks amazing -- and we all know that makes it faster.
Dan Ainge
RV-7A N375M
2017 =VAF= dues paid
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Old 06-11-2017, 07:49 PM
mmcelrea mmcelrea is offline
Join Date: Dec 2008
Location: Northern Ireland
Posts: 8

Hi Dan.
What is the takeoff distance and landing distance with the catto on the aerosport? Thinking the same combo myself but will be operating of a short grassstrip, 450yards.
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