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rolivi

Well Known Member
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I need a Fixed Pitch prop for an RV-6A with an O-320 (160hp)

I'm more interested in cruise speed. I don't plan to get into acrobatics, beyond the occasional roll or loop. No mountain or extremely short fields in the flight plans.

I'm looking at wood props:
Sensenich - 2 blade
Catto - 3 blade
Performance Propellors - 3 blade
Sterba - 2 blade

Looks like the costs of the 3-blade props are roughly the same, as are the 2-blade props, so about 2k difference from 2 to 3 blade (all in)

I know this like asking Tail-dragger vs Nose wheel, or High Wing vs Low for the certified plane crowd, but I'd like this to be my last prop purchase :)
 
If difference in price is irrelevant get a 3-blader. A bit more clearance from the planet's surface and runs smoother. :)
 
pricing

If difference in price is irrelevant get a 3-blader. A bit more clearance from the planet's surface and runs smoother. :)

I'm comfortable staying under 5k. When I look at 12k for an electric C/S I need to slow down and remember that Autumn needs dogfood and a place to live :)
 
I've run many different props on my -6 in the last 22+ years.

No other F/P prop that I've found comes close to the Catto 3-blade.

It's Sexy looking, It's smooth, It's Sexy looking, It's quiet, It's Sexy looking, It's fast, It's Sexy looking, and it's efficient!

Oh yeah, did I mention, It's also Sexy looking.
 
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Doesn't the three bladed prop make the bottom cowl removal/installation more difficult for a tricycle?
 
I knew popcorn was needed

Don't drive a tricycle!

I can't drive a 6A without a nose wheel. I tried it once and now I need a prop (but that's a different thread)

If removing the cowls is a consideration I'd like to hear more about that.
 
smiley-face-eating-popcorn.png
 
It does require some modification

I replaced my 2 blade wood prop for a three blade Catto Prop. After all the instalation was don I sat back and admired a beautiful prop and the attached plane. Took to the air and enjoyed the flying! A few hours later The oil change needed to be done. :eek: what did I do? The bottom cowling required modification. I had to extend the slot for the front gear by about 8 inches. of course that gave me the opportunity to use the custom fairings from fairing-etc.com to cover the slot. All is well now and you cant beat the look of the 3 blade or the performance of a Catto.
 
I realize this thread is a Catto lovefest, but I'll suggest the metal Sensenich. It is an excellent all-around prop which I have been flying for 16 years on the RV-6. Mine is pitched @ 80" for cruise with 160hp O-320.
 
I realize this thread is a Catto lovefest, but I'll suggest the metal Sensenich. It is an excellent all-around prop which I have been flying for 16 years on the RV-6. Mine is pitched @ 80" for cruise with 160hp O-320.

Pardon the completely off-topic posting about some crazy metal propeller. Now back to your regularly-scheduled Catto "lovefest". I know I sure love mine! It's a sexy three-blader too! (Not sure whether it's as sexy as Mel's or not though :p)

(Just kiddin', Sam!)
 
I realize this thread is a Catto lovefest, but I'll suggest the metal Sensenich. It is an excellent all-around prop which I have been flying for 16 years on the RV-6. Mine is pitched @ 80" for cruise with 160hp O-320.

Sam, metal props are so last century. Don't you know the new hot setup is to have a wood prop? ;)
 
Sam, I'll join in with a 16 year old sensi. Smooth, durable, and fast. Just touch up the leading edge, paint the face once a year and go flying. Now 4,000 + hours later spinning like new.
 
Perspective

...
It's Sexy looking, It's smooth, It's Sexy looking, It's quiet, It's Sexy looking, It's fast, It's Sexy looking, and it's efficient!

Oh yeah, did I mention, It's also Sexy looking.

Mel, at our age, EVERYTHING is "Sexy looking!" :D
 
Sort of thread drift, but I have been looking at the Whirl Wind ground adjustable, for approx $3,000. I currently have a wood fixed pitch that just isn't quite perfect for my engine / airframe combination and I have sent the prop back once for fine tuning. With a ground adjustable you can dial in the performance and then lock it down for the perfect pitch setup. Just an opinion / different setup.

Note: This is not to say that any of the above listed props are not good.
 
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Except that the engine's rated HP is usually 2750 RPM... That 150 RPM is worth a few HP. If you paid for 160 HP (as a buddy did for his -9A), you never get to use it.
 
Except that the engine's rated HP is usually 2750 RPM... That 150 RPM is worth a few HP. If you paid for 160 HP (as a buddy did for his -9A), you never get to use it.

You will never get 160 hp with a fixed pitch prop on an O-320 regardless of brand.
 
OK, I've got a fresh bucket of popcorn ready....so here goes....

Sensenich composite ground adjustable prop.

No rpm restrictions.
Fast in cruise, or powerful in climb. You get to choose the pitch that best fits your airframe and engine.
Sexy as all can get out... It's a beautiful sexy looking prop.
Smooth, as in turbine-smooth.
Lightweight as any wood prop.
Stainless steel leading edges so you can fly in rain worry-free of eroding the leading edge.
The only bad thing is cost, it's not cheap, but definitely fits the "buy once cry once" adage.

I love mine and would buy again in a heartbeat.

PS: I have mine pitched so that I was able to hit right at 2700 rpm at 7500' MSL on my way to Oshkosh at full throttle, leaned to peak rpm. True airspeed was almost 200 mph, about 172 kts... at 7.6 gph. You can't beat that with a stick.
 
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You will never get 160 hp with a fixed pitch prop on an O-320 regardless of brand.

Not sure where you get that. With the proper prop a 160 hp rated O-320 should get 160 hp at sea level and 2700 rpm.

If you mean "on take-off" I'll agree, but that's not what you said.
 
Yep, every foot above sea level gets you less and less HP. In my case, even though I can turn 2700 at 7500MSL, my engine is putting out much less (more like 124hp if I'm lucky) than 160hp. But being able to still spin the prop at 2700 gets me more airspeed at altitude.
 
You will never get 160 hp with a fixed pitch prop on an O-320 regardless of brand.

OK, if you're taking the position that every inch of altitude is lost power on an NA engine, correct. But the inability to use that last 150 RPM is power "left on the table" no mater what you start with. Its a loss of capability, plain and simple.

Fixed pitch props shine at blade efficiency... For a fast airplane like an RV, you should just be able to touch redline at max level speed - right where thrust and drag cancel each other out. True, such a prop is not going to give you max RPM on the takeoff roll, but it seems a shame to hamstring the engine on both ends of the speed range.
 
That prop carries a pretty significant RPM restriction, doesn't it?

Plus one on the metal Sensenich.

It goes with my last century Lycoming.

I'm also starting a prop search for my 9A and really like the look of those 3-blade props, but I have one nagging problem.

I currently fly a Cherokee 180 with a Sensenich and an RPM restriction. It was explained to me that the RPM restriction is due to unfavorable mechanical vibrations and stresses that occur inside the engine at those RPM levels, and that long-term use within the restricted range could cause engine damage. But it was also explained that this problem was only discovered during certification testing of that particular engine/prop combination, when the engine is extensively instrumented.

So if I buy a non-certified engine/prop combo, and it doesn't have any RPM restriction, is that because the problem doesn't exist, or because it hasn't been examined? Is this anything I should worry about?

John
 
?...

So if I buy a non-certified engine/prop combo, and it doesn't have any RPM restriction, is that because the problem doesn't exist, or because it hasn't been examined? Is this anything I should worry about?

John
If you buy an experimental aircraft, I would highly recommend reviewing the manufacture and part number of the prop with any available TCDS's for any special operating limitations. If there are any limitation, such as the Sensenich 70CM series, I would recommend following them. If there isn't a TCDS, call the manufacture.
 
If you buy an experimental aircraft, I would highly recommend reviewing the manufacture and part number of the prop with any available TCDS's for any special operating limitations. If there are any limitation, such as the Sensenich 70CM series, I would recommend following them. If there isn't a TCDS, call the manufacture.

Such data does not exist for experimental props; however, wood based props tend to dampen the harmonics that can cause engine damage. The exception to this seems to be the Sensenich ground adjustable props which are so stiff they are causing problems in some engines because the transmit a lot of vibrations to the engine rather than dampen it.
 
Not sure where you get that. With the proper prop a 160 hp rated O-320 should get 160 hp at sea level and 2700 rpm.

If you mean "on take-off" I'll agree, but that's not what you said.

Who flies at sea level? Maybe on a cold day.
 
OK, if you're taking the position that every inch of altitude is lost power on an NA engine, correct. But the inability to use that last 150 RPM is power "left on the table" no mater what you start with. Its a loss of capability, plain and simple.

Oh no...you mean I (and who knows how many other RVers) have been cheated out of a capable RV for the past sixteen years because of a "lost" 100 rpm? What is this going to do to my plane's self-esteem? ;)
 
Such data does not exist for experimental props; however, wood based props tend to dampen the harmonics that can cause engine damage. The exception to this seems to be the Sensenich ground adjustable props which are so stiff they are causing problems in some engines because the transmit a lot of vibrations to the engine rather than dampen it.

The RV Series Sensenich 70CM prop is certified with a TCDS, which is the prop I was referencing. That is why I stated "any available".
 
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I was simply responding to your "never" comment.
At what altitude do you get 100% power with a C/S prop?
And who flies at 100% power?

Exactly, and that is why the concern over the "lost 100 rpm" with the metal Sensenich on a O-320 is way overblown. We pitch that prop for max performance at 2600 rpm and never miss the other 100 rpm in real world flying.

This was a hot topic of discussion when the prop was introduced nearly twenty years ago but has been put to bed by the hundreds (thousands?) of RVs flying it since.
 
Exactly, and that is why the concern over the "lost 100 rpm" with the metal Sensenich on a O-320 is way overblown. We pitch that prop for max performance at 2600 rpm and never miss the other 100 rpm in real world flying.
This was a hot topic of discussion when the prop was introduced nearly twenty years ago but has been put to bed by the hundreds (thousands?) of RVs flying it since.

Why are you quoting me and talking about rpm loss? I never mentioned anything about rpm loss. I was simply talking about you comment that one could not achieve 100% power with any fixed pitch prop.

I'm out of here!
 
Why are you quoting me and talking about rpm loss? I never mentioned anything about rpm loss. I was simply talking about you comment that one could not achieve 100% power with any fixed pitch prop.

I'm out of here!

Mel, I'm agreeing with you. :)

The comment about the 100 rpm is in reference to the posts that started this branch of this thread about the metal Sensenich.
 
Mel, I'm agreeing with you. :)
The comment about the 100 rpm is in reference to the posts that started this branch of this thread about the metal Sensenich.

Sorry. I misread your post. I missed the beginning "Exactly!"
 
I don't know how the discussions went 20 years ago, but pointing out that a loss of RPM is a loss of HP is something to consider for a new buyer. Maybe the 2600 RPM restriction works for you, but you cant speak for everyone just because you are satisfied with the performance of your airplane. What if the restriction was 2400 RPM, would you still be OK with that?

Also remember that if the prop is pitched for a lower RPM at max cruise, you are also turning even lower on takeoff - a regime of flight that you fixed pitch guys struggle with anyway. Yes, plenty of RV's do "fine" with this prop. But "fine" isn't good enough for everybody.
 
I've run many different props on my -6 in the last 22+ years.

No other F/P prop that I've found comes close to the Catto 3-blade.

It's Sexy looking, It's smooth, It's Sexy looking, It's quiet, It's Sexy looking, It's fast, It's Sexy looking, and it's efficient!

Oh yeah, did I mention, It's also Sexy looking.

mel, i now pronounce you man and prop.
 
RPM

Mel, what RPM do you see with your Catto during your takeoff roll? My 0320/metal Sensenich is running about 2200RPM at 70' msl on a hot day. John
 
The verdict

I've decided to go with sexy.

Lot's of good info in the thread, and lot's of Catto love.

Deciding factors: Good feedback from people flying them
Great customer service on email quote and follow up call
Excellent availability (1-2 weeks)
Price works for my budget
 
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