Yet another Prop question

Hi all,
I know, I know, propellers have been worked over in the forums, but I have one more question. Does the Sensenich 72" metal prop (72FM8S16-1 (85) - RV-4 180 HP) that Van's sells, have the same RPM restriction as the 70"?

http://www2.sensenich.com/direct/vans.htm

There ya go.

Plus and Minus of the Sensenich 180 hp prop.

rvbldr3170 said:

Hi all,
I know, I know, propellers have been worked over in the forums, but I have one more question. Does the Sensenich 72" metal prop (72FM8S16-1 (85) - RV-4 180 HP) that Van's sells, have the same RPM restriction as the 70"?

Click to expand...

On the plus side, the 180 hp prop does not have the rpm restriction.
On the minus side, the 180 hp prop is not certificated and is not quite as efficient as the 160 hp prop.

Plus and Minus of the Sensenich 180 hp prop

Is anyone using this combination on an RV-4?
O-360 (9:1 compression) Carbureted
Sam James cowl and plenum
Sensenich 72" metal prop (72FM8S16-1 85)

How much less efficient is this prop vs. the certified version, and how was that determined.

I am really on the fence about this prop thing, and I don't want to buy 3-4 props to get it right. I won't be doing any hard acro, only mild stuff.
And cruise speed is important to me. My home airport is 1041' MSL (Ohio) so altitude is not a factor for takeoffs and landings.

I know a lot of people like wood, but everyone I know has gone through several wood props before they have settled on one.

Catto is also an option, but his props are almost as much as the Sens.

Any input from those that have "been there done that" would be appreciated

If you go to the Sensenich webpage and look at the testing entries, you'll see that Martin Sutter did much of the testing on the 180 hp prop. If you compare the data of the metal prop vs. Martin's Sensenich wood prop, you'll see little difference in performance. As a matter of fact, the wood out performs the metal in a place or two.

Can't speak to efficiency, but I originally planned on wood and bought a Sterba. It's a beautiful thing, but I became concerned about long term maintenance and switched over to the metal Sensenich. After working with that wood prop, I was shocked at how heavy the metal prop is when it arrived. It really weighs a whole lot more but I've fitted it and I'm sticking with it. I've still got the brand new Sterba if anyones interested in it.

Prop me up...

Merle,
No RPM restriction on the 72" 180 HP metal sensy. In fact, one RV8 buddy went with 85 pitch as he could turn 2800 RPM at altitude and beat Hartzell dudes! Heavy, yes. Fast, yes, but no faster than a Catto or even Hartzell BA. If you don't do alot of acro, do like going XC and fly through rain, you have the right prop.

My pick for the 0-360? Catto my brother, Catto...

Smokey
HR2

www.cattoprops.com

What Smoky said....

......Catto.......

Regards,

Catto vs. Sens.

Smoky,
How in the world do you figure out the pitch difference between manufacturers?
Craig told me he recommends the 72x74 for my setup, and that sounds a LOT different than the 72x 85 sensenich that Van's sells.
I know this subject has been thrashed to death but I'd sure appreciate some enlightenment

No correlation between manufacturers.

Pitch measurements will not correlate between manufacturers. Everyone measures a little differently.

rvbldr3170 said:

Smoky,
How in the world do you figure out the pitch difference between manufacturers?
Craig told me he recommends the 72x74 for my setup, and that sounds a LOT different than the 72x 85 sensenich that Van's sells.
I know this subject has been thrashed to death but I'd sure appreciate some enlightenment

Click to expand...

What Mel said.

In fact, when I run the pitch numbers against my RPMs and speed, the Catto prop comes out to be 110% efficient and I know that just ain't right.

Prop-er Pitch...

Merle,

I was fortunate enough to have eleven buddies flying RV4's and one RV8 in my squadron right after 9/11. We had every prop and engine combination and I became familiar with all of them.
All of the manufacturers seem to measure Pitch at different blade stations along the blade. Therefore testing and familiarity is the best course of action to determine performance.

The Rocket of course, defines performance

Smokey
HR2

More on props

Smokey,
I gotta chime in here. I purchased a flying 1993 RV4, 0320 B2C 160 HP (2700 rpm) with a Bernie Warnke 72x70 wood prop (still in good condition). At 8000 ft I show 23" MP, 2700 RPM and only 180 MPH. Climb seems good at 2000 fpm solo. There is another RV4 moved into the area built by some guy on the Ohio River, 150 HP and 190MPH. I just cant be having this! What can I do?
Thanks!

Does it compute?

Dan,

It's not the big things, but a combination of alot of small things that gain performance. First, those aren't bad numbers for an RV4 at 8000'. Compare ground speeds or just race him and see what he is really doing. Maybe his airspeed is "self induced". My 150HP RV4 would indicate 210 mph/169 knots GS at SL, full throttle 2800 RPM when I finished tweeking it. Make sure you have fairings at all the gear intersections, flap gap seal at fuselage, tight empennage fairing, mags timed correctly, REM37BY plugs(hotter).

Having played with my RV4 for 13 years, my prop seemed to be the biggest improvement in speed along with Ram air and Electronic Ignition. When I had the 150HP 0-320, I ran a Warnke 69X70 ACS prop that just wasn't quite giving me what I thought The Bandit should be doing, so I sold it. After running my old Sterba spare (which gave OK performance), I visited Craig Catto. He wasn't making RV props at that time, but let me borrow a prop from a 160HP Glasair the owner returned. Wow, what a difference! I gained 15 knots at the top end and the whole airplane was smoother. It was a bit too much pitch for The Bandit, so me made me a new prop, his 1st 2 blade RV prop. Whack, home run! It would turn 2850 up high but that was OK by me since the MP was low.I was truing out at 165 Knots at 10,500' on 8.8 GPH. Below 5000' I could hang with any RV, any HP, except maybe Dave Anders. This with only 150HP. Your 160HP should be easily doing 165 Knots True at Altitude.

My point? After checking everything else, Catto, my brother, Catto TWO Blade. I know, everybody says his new 3 blades are better than before, but I can attest that the 2 blade on the 0-320 Rocks!

Smokey
HR2

Thanks Smokey

Thanks for the reply!!!

Merle,
Suggest calling ED Zerker at Sensenich - 717 569 0435
Known him a long time - very knowledgeable.
Regards,

Geoff Kimbrough
RV-8 flying
Stearman - Flying
Katy, Texas

Sensy Metal on an 0-320? Not me!

Merle/Dan,

As I have said before, if you like aerobatics, light nose, no RPM restrictions (i.e. rated power from your 0-320 is 2700, not 2600) smooth running and no flywheel effect then don't buy a 70CM Sensenich! I had one for 1 month and happily sold it.

However comma, if you like performance with smoothness and light weight and do aerobatics and like passing guys with 2600 rpm restrictions...talk to my friends Gary Hertzler (CAFE Challenge winner) or Craig Catto (World record holder) Craigs props have raced at Reno and grace the tails USAF Predator UAV's..



BTW, this is the AR-5, World Record holder (still) doing 213.18 MPH on 65HP. It has a Craig Catto prop!

Smokey
1500 hours RV4
300 HR2 and loving every second...

http://www.ar-5.com/sportav93.html
www.cattoprops.com
[email protected]

I wonder who that guy on the Ohio River was ??

Dan, That's a 'special' little RV4. It's light weight and the prop/engine combo is PERFECT. I didn't build it as a 'show plane' but as an example of a fun lightweight 'sporty' RV4....just what Van had in mind if you ask me. And, YES...it's 150hp.

FACT: I've had more than 1 200hp RV8 C/S 'beg' me for power on the climb out when I owned the plane (similar pilot weight and fuel) .

FACT: After I sold the RV4 to a friend at my airport I used to 'try' to keep up with him on the climb out with 2 different 180hp C/S RV7's. It never happened....he ate me up .

Again...both the above 'FACTS' are side by side comparison and NOT hearsay...I was there.

My only disappointment was that I never 'raced' any of the 180/200hp RV's in level flight while I had the plane. I DID race quite a few 160hp RV's side by side and it was like.....'see you later'.

One more FACT.....I flew alongside of my old RV4 with my new F1 Rocket about 2 weeks ago......my Rocket ate the little RV4 for lunch....and was still hungry for more RV's !!

Sorry Dan...but I doubt you'll be able to keep up with 806RG, she's a zippy little bugger.

hempy.4 said:

Smokey,
I gotta chime in here. I purchased a flying 1993 RV4, 0320 B2C 160 HP (2700 rpm) with a Bernie Warnke 72x70 wood prop (still in good condition). At 8000 ft I show 23" MP, 2700 RPM and only 180 MPH. Climb seems good at 2000 fpm solo. There is another RV4 moved into the area built by some guy on the Ohio River, 150 HP and 190MPH. I just cant be having this! What can I do?
Thanks!

Click to expand...

Speed is Life...

With the right Catto 2 blade, you have a chance...
With a Harmon Rocket, adios amigo!
With an F-16C, Yee-Ha!

Smokey
HR2

It would really stink to have Mike Arnold motor on by in his 65HP AR-5!

I may be able to help narrow your prop choice down a bit depending on when you want to get it.

I placed an order for a Sensenich the first week of October. I was initially told the prop would be delivered the first week of December, this was slipped to the 20th of December. I called Vans about 3-4 weeks ago and asked for an update. They checked with Sensenich and got back with me. Vans told me Sensenich said they didn't know when it would be delivered. Vans encouraged me to contact Sensenich directly.

I emailed Ed Zerker at Sensenich and asked what was up with my order. He said they are having problems getting the forgings for the props. They were working with a different source but it would be at least March before they could get them and add to that the time it takes to produce the prop.

He went on to say that he couldn't tell me when or even IF my prop would ever be delivered. Bad news but at least they're honest. He said if I keep in touch he would keep me informed even if the news was bad news.

So, the bad news is if you order or have a prop on order, you may be in for a very long wait. I would check with Sensenich before placing an order to find out if they can produce the prop you need, in the timeframe you need it. If you have one on order, call or email Ed as you may want to evaluate your options. If you need/want it in the next 6 months you may be disappointed.

The good news is, there's a group buy going on for prop govenors and guys are upgrading their props, so there may be some used props coming up for sale. The day I found out Senenich was having problems, I placed a "WTB" in the classifieds here on VAF. Within 24 hours I had two replies/offers. Within 48 hours I had confirmed the deal and bought my prop (thanks to Bob Martin!).

I don't think wood props from Sensenich is a problem. It would be a great time for Sensenich to develop a composite for the RV!

I almost went with a Catto because everyone seems to love them. They're great looking props too. The only complaint I've heard about Catto is the time it takes to get one. However, that may not be an issue now. I read somewhere he has added people/equipment and can keep up with demand.

Finally, if you are reading this and you have a prop that you don't need right now, it's a great time to sell.

catto prop and speed

If you all want to know how your plane runs compared to other RV's bring it out to one of the SARL races next year. I ran several races unchallenged in the RV RED class this past year. I always hear about fast RV's on this forum but nobody seems to want to prove their claims. Why is that?

The Catto prop really brought the performance out in my airplane. My stock engine and plane can run with some of the 360cu RVs that I have raced with.

Watch the SARL website, we could really use some racers in the RV-RED class. in 2009.

Chris Murphy RV-4 race 34

Brrrrr!

Why don't you guys have it at my strip, -17 as I am passing through DEN today....72 at home...

Smokey
HR2

rv6rick said:

Dan, That's a 'special' little RV4. It's light weight ....

Click to expand...

So what does it weigh in at?

RV-4 weight

My -4 weighed in at 945lbs before first flight but since then I have added a Dynon d10 and a transponder/encoder.

Got up to plus 3 deg. here today and supposed to be even colder tonight than last night. Enough winter already, let's just skip ahead to June! It was so cold the old Pratt and Whitney stopped accelerating and began to decelerate after starter cut-out. Never seen that before.

C Murphy

I like the Sens. metal prop!

After having two wood prop blades 'depart the fix' on seperate occasions while airborne resulting in a pretty scary descent and unplanned landing, I determined to keep wood in the trees and went with a metal Sensenich on my RV-4. Loved it! Spent a little time getting the best balance and flew it to OSH twice with lots of XC time in between. I enjoy acro in my planes and had no problem with my metal prop, my conservative rule being 3-4 Gs max. A BIG plus was the extra weight on the nose allowing literally no weight restrictions in the back seat (Max test...300#s!).

Another BIG plus is not having to worry about torque values, moisture seepage and flying in the rain. Finally, when I lost my wood prop inflight I was stuck out away from home, called Sensenich and they said "6-9 weeks to get a prop." But when I explained my dire situation, within a week I was happily flying my new prop/RV-4 combo. They are good people.

My new RV-4 will have a BA Hartzel this time to keep the noise and RPM down but I liked my fixed pitch Sens. and the USAF test pilot that bought my flying -4 three years later is still loving it up in the Northeast sooooo...to each his own but don't discount the metal Sensenich!

Tailwinds,