Spinner for Catto 2 blade prop

I am changing from a Sensenich to a 2-blade Catto. Hub thickness of Catto measures 4 1/4" thick. The plan is to order Vans spinner kit FP-13 so I can sell the Sensenich prop with the spacer and spinner kit if the Catto turns out to be an improvement.

Ken at Vans suggested there could be some finagling with spacers to get the front bulkhead in the right place (apparently wood prop hub thickness varies by manufacturer).

Can anyone who has made this conversion please tell me what was involved fitting the spinner kit to their Catto prop.

Thanks,

LarryT

When I converted to a Catto from a Sterba I used the same backing plate and just bought a new spinner. Fitting it was pretty straight forward, trial & error. I think I cut sone stiff paper and traced in on the spinner. I used a die grinder to shape the cut out.

Larry,

Open your wallet and have Craig cut your spinner for you. He will charge for his time and a Van's spinner kit.

Money well spent IMHO.

I did this swap this summer and it worked great. Catto told me exactly what to do, like ordering a Saber spacer. His instructions were spot-on. He's done this many times. In addition to the Saber spacer, which comes complete with prop bolts, you order a new backing plate fron Vans and re-use your existing spinner.
Ask Catto...

Bill Newkirk
N283RV

Craig v. DIY

Perhaps Craig is too busy these days. I had a discussion with Craig about reusing the old spinner or buying the spinner kit from Van's. Craig's suggestion was to buy the kit from Van's and do it myself. It was Ken at Van's that brought up the idea that not all prop hubs are the same thickness.

The reason for my post was to understand whether or not I would really have to use spacers to get the front spinner bulkhead in the correct place. I am neither adverse to doing it myself (or having Craig do it, but he didn't seem interested), I would just like to have all the parts on hand when I start the task.

Larry

N941WR said:

Larry,

Open your wallet and have Craig cut your spinner for you. He will charge for his time and a Van's spinner kit.

Money well spent IMHO.

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Assemble it!

Only one way to find out! Put her together and see what happens. In my case, the spinner bowl contacted the front bulkhead before the rear bulkhead(this is a 12" spinner kit). I sanded smooth the area of the spinner bowl where it contacted the front bulkhead, that helped, but I still had to do a couple fiberglass layups so the spinner would fit snug on the rear bulkhead. Im anxious to see what this Catto will do. I will have it on this week. WHOOPIE! FSDO is supposed to be calling me back with their requirements....

FSDO requirements

Let us know if its anything other than the 5 hrs. Phase I others have mentioned.

Larry

hempy.4 said:

Only one way to find out! Put her together and see what happens. In my case, the spinner bowl contacted the front bulkhead before the rear bulkhead(this is a 12" spinner kit). I sanded smooth the area of the spinner bowl where it contacted the front bulkhead, that helped, but I still had to do a couple fiberglass layups so the spinner would fit snug on the rear bulkhead. Im anxious to see what this Catto will do. I will have it on this week. WHOOPIE! FSDO is supposed to be calling me back with their requirements....

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Not a major change

My Operating Limitations say to contact the local FSDO prior to flying the aircraft after a Major Change as per FAR 21.93(a) So I called and talked to an Airworthiness Inspector. He told me that replacing a wood prop with a new wood prop is not a major change and all I had to do was make a logbook entry. He viewed a Major Change as swoping out a wood prop for a CS prop. So, good news here!

What engine

The sensi prop you might sell is for what engine. What is the pitch and diameter of the Catto?

I made the switch on my 320 rv-4 a few years ago. Used the same spinner and back plate with a New Front plate, just did some glass work.

Chris M

Purchased spinner kit from Van's

The engine is an O-320. I just decided that it would be nice to keep the current spinner and prop together. I expect the Catto to be an improvement, however, if the Catto doesn't work out and I go back to the Sensenich, the change back will just be a bolt-on. If I keep the Catto and sell the Sensenich, then it will just be a bolt-on for whoever purchases it.

Thanks everybody for your e-mails.

LarryT

Christopher Murphy said:

The sensi prop you might sell is for what engine. What is the pitch and diameter of the Catto?

I made the switch on my 320 rv-4 a few years ago. Used the same spinner and back plate with a New Front plate, just did some glass work.

Chris M

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I hate to drag up old threads but can any of you that switched from the Sensi on the RV-4 with a 320 to the Catto share performance numbers?

RV-6A prop switch

Sid Lambert said:

I hate to drag up old threads but can any of you that switched from the Sensi on the RV-4 with a 320 to the Catto share performance numbers?

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Sorry, no RV-4 data. The 6A I purchased flying is not the aerodynamically cleanest one ever built. It is a really nice flying plane.

With an O-320, the Sensenich propeller has a 2600 RPM limitation. My -6A, which still has the old style wheel pants and aluminum gear leg fairings would cruise at 180 - 182 mph @ 2600 rpm.

With the Catto 2-blade prop it will now cruise as high as 190 - 192. There is a fuel consumption penalty, of course. I am not sure I have the optimum pitch. The engine was modified by Ly-Con and they were unwilling to provide dyno data that would have helped determine appropriate propeller pitch, so I have had to rely on "cut and try." As received, the propeller was pitched for 160 HP and easily over revved. After re-pitching, it now seems like there is just a little too much pitch. I am holding off on any further adjustments until after I get the time to install the late model wheel pants and fairings and adjust the rigging.

LarryT