VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics


Go Back   VAF Forums > Model Specific > RV-9/9A
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #11  
Old 06-27-2017, 07:08 PM
Dbro172's Avatar
Dbro172 Dbro172 is offline
 
Join Date: Apr 2012
Location: West Fargo, ND
Posts: 889
Default

If nothing else, i would sell the metal FP sensenich and go with a composite Catto or ground adjustable sensenich or whirlwind. I think the performance increase from the metal FP to a wood or composite FP will be a better value than going to constant speed. I would like a constant speed but as others have said probably only improves the takeoff, which, given the FP performance, probably doesnt justify the added cost, maintenance and weight.
__________________
Derek Hoeschen
EAA Tech Counselor
RV-9A #92103 - N803DK
G3X, Superior XO-320, Whirlwind GA
www.mykitlog.com/dbro172/

RV-8 #83565 - N184DK - building
1968 Mooney M20C - Sold
1956 C-182 - Sold
Reply With Quote
  #12  
Old 06-27-2017, 08:55 PM
grubbat's Avatar
grubbat grubbat is offline
 
Join Date: May 2012
Location: Ga
Posts: 440
Default My experience

I've got a CS prop on a -9. I tried out several Catto FP props. The Catto gives good performance at a lower cost and less nose weight which is important to the -9a. That's what I would go with if I had a -a model.

In a nut shell, top speed was similar between Catto and CS.
However, takeoff is an entirely different matter. My -9 is off the ground by the time I push the throttle all the way in and I'm at pattern altitude before end of 5000ft runway. Takeoffs are really fun and the -9 wing gives an exciting climb.

That being said, the Catto would be my choice if I wasn't addicted to the climb and the braking action of CS. Especially in a -a model with that toothpick nose gear.

Good luck!!



Quote:
Originally Posted by 9GT View Post
Anybody have any performance comparison numbers switching from the Sensenich F/P propeller to a C/S prop on their RV-9 or -9A? My project, RV-9A, came with the Sensenich F/P prop, but the engine, Mattituck IO-320, is capable of C/S by removing the CS plug and adding a governor. I know the benefits of a C/S prop but just trying to figure out if I want to make the switch while the F/P prop is still new in the box. I would love some before and after the swap performance numbers to help me justify the added costs. Thanks! Dave
__________________
Craig

RV-3 Sold
RV-6a Sold
RV-9 Flying
Reply With Quote
  #13  
Old 06-27-2017, 09:09 PM
Steve Melton's Avatar
Steve Melton Steve Melton is offline
 
Join Date: Apr 2011
Location: Cincinnati, OH
Posts: 1,180
Default

Quote:
Originally Posted by grubbat View Post
I've got a CS prop on a -9. I tried out several Catto FP props. The Catto gives good performance at a lower cost and less nose weight which is important to the -9a. That's what I would go with if I had a -a model.

In a nut shell, top speed was similar between Catto and CS.
However, takeoff is an entirely different matter. My -9 is off the ground by the time I push the throttle all the way in and I'm at pattern altitude before end of 5000ft runway. Takeoffs are really fun and the -9 wing gives an exciting climb.

That being said, the Catto would be my choice if I wasn't addicted to the climb and the braking action of CS. Especially in a -a model with that toothpick nose gear.

Good luck!!
I agree with this sentiment. Now that is resolved, where's the beer tent?
__________________
Steve Melton
Cincinnati, OH
RV-9A, Tip-up, Superior O-320, roller lifters, 160HP, WW 200RV, dual impulse slick mags, oil pressure = 65 psi, EGT = 1300F, flight hours = 500+ for all

Simplicity is the art in design.

Last edited by Steve Melton : 06-27-2017 at 09:12 PM.
Reply With Quote
  #14  
Old 06-28-2017, 02:00 AM
dlomheim dlomheim is offline
 
Join Date: Sep 2006
Location: (2OK2) OK City, OK
Posts: 335
Default 9A Nose Gear

Quote:
Originally Posted by grubbat View Post
...the Catto would be my choice if I wasn't addicted to the climb and the braking action of CS. Especially in a -A model with that toothpick nose gear...
So how does the 9A "toothpick" nose gear differ from that on the 7A? Since the fuselage's are the same, I always assumed the two were the same nose strut...

Doug Lomheim
RV-9A Mazda 13B/FWF
RV-3A sold
Reply With Quote
  #15  
Old 06-28-2017, 04:30 AM
plehrke's Avatar
plehrke plehrke is offline
 
Join Date: Sep 2006
Location: Defiance, MO
Posts: 1,346
Default

Quote:
Originally Posted by dlomheim View Post
So how does the 9A "toothpick" nose gear differ from that on the 7A? Since the fuselage's are the same, I always assumed the two were the same nose strut...

Doug Lomheim
RV-9A Mazda 13B/FWF
RV-3A sold
Excellent, we are ending the never ending debate on f/p vs c/s with starting a never ending debate on nose wheel vs tail wheel.
__________________
Philip
RV-6A - 10 years over 750 hours
Cessna 140 - 68 years over 3400 hours
Based at 1H0 (Creve Coeur)
Paid dues yearly since 2007
Reply With Quote
  #16  
Old 06-28-2017, 04:39 AM
rzbill's Avatar
rzbill rzbill is offline
 
Join Date: Nov 2005
Location: Asheville, NC
Posts: 2,388
Default

Quote:
Originally Posted by N941WR View Post

The only advantage the CS prop gives you is on takeoff acceleration. Cruise speeds can be identical, with often the advantage going to the FP prop. However, to do that, you have to spin your FP prop on the redline, which the engine is designed to do.
Bill, I'd like to comment and add a bit.

Takeoff. True
Cruise speed. Can be true (often? Hmm) but by definition of prop design the FP climb will be anemic compared to CS in that situation.
Spin to redline. Yes you can. However, if one reviews the Lyc engine performance documents, you can see lower RPM improves fuel economy because of differences in frictional horsepower and the theta P timing effects. As a side note, this is one reason I have not jumped to EI yet.
Decent. A CS prop can leave an FP in the dust on decent with the ability to run high power levels without overspeeding the engine.
Deceleration. While I do not use it, the CS can give temporary braking in the pattern by a sudden shift to fine pitch.
__________________
Bill Pendergrass
RV-7A: Flying since April 15, 2012. 650hrs
YIO-360-M1B, mags, CS, GRT H1s & A/P, Navworx
Unpainted, polished....kinda'
My RV Construction Page

Last edited by rzbill : 06-28-2017 at 05:11 AM.
Reply With Quote
  #17  
Old 06-28-2017, 06:53 AM
9GT's Avatar
9GT 9GT is offline
 
Join Date: Jan 2010
Location: Southern Michigan
Posts: 1,142
Default

The Sensenich that came with my project has a 2600 rpm limitation also and the engine is rated 160hp @ 2700 rpm. An extra 100 rpm can be noticeable on take offs so whether I go to C/S or stay with F/P, I think I want to change out the prop. I've noticed just moving the plane around in the hanger that the nose wheel strut does seem a bit "flimsy" as compared to my old -10 so I definitely want to keep the FWF as light as possible. I am not looking to debate whether a F/P or C/S prop is better or not, I am just looking for some actual performance numbers from people who have made the switch, or even some numbers from folks who have switched from the F/P Sensenich to another brand of F/P such as a Catto or other brand.
__________________
David C.
Howell, MI

RV-9A: Under Construction
RV-10: N959RV Completed 12/29/2013 SOLD 08/23/2016

"Donor Exempt" but donated through Dec. 2017
Reply With Quote
  #18  
Old 06-28-2017, 10:04 AM
MS19087's Avatar
MS19087 MS19087 is offline
 
Join Date: Nov 2006
Location: PA
Posts: 517
Default I'm on my third prop

My -9A started life with the Sensenich metal prop on my IO-320 (rated at 170HP - high compression, flowed and balanced w/ P-Mags). After about 20 hrs I decide that the RPM limit didn't allow me to get the performance i wanted. I switched to a Whirlwind GA200 ground adjustable prop. I really liked that prop - when dialed in correctly (after 3 attempts) i found a setting that gave me excellent climb and cruise performance. I used that prop for 300 hrs, then came upon a great deal on a WhirlWind WW151 - 3 bladed CS prop. I installed that this winter and now have about 20 hrs on it. Take off and climb is like a different plane - top end cruise is similar, maybe slightly better. This CS only weights 28 lbs - so it is the same weight as the FP Sensenich. Granted, i would not have changed out the prop unless the economics worked - likely would not have paid full retail ($10K+) for the 151. However i am very happy i have it.

Did a re-weight last week with the WW151 - here are my numbers:

NOSE - 250
LEFT MAIN - 451
RIGHT MAIN - 455
__________________
Mark
RV-9A; IO-320 w/ Whirlwind WW-151
(Flying since June 2011)
2017 =VAF= donor

Last edited by MS19087 : 06-28-2017 at 10:07 AM.
Reply With Quote
  #19  
Old 06-28-2017, 03:15 PM
scottmillhouse scottmillhouse is offline
 
Join Date: Apr 2007
Location: Madison, AL
Posts: 125
Default vote for CS prop on a 9A

On my 9A I tried a wood that was too flat a pitch (climb prop) causing 2700 RPM with a max speed of 180 mph and 1700fpm max climb- weight from W&B 417#, 403# and 237#. Eventually switched to a Hartzell CS with max 2000 fpm climb and 195mph at 2650 or 2700- weight 418#,408# and front at 273#. 42# also included Nav radio and ILS and nose wheel, strut upgrade and anti-splat. Loved the climb, ability to select cruise on MP and RPM and the braking effect. No CG problem ever with any loading with CS. Slightly biased to front means that unlike a light fixed pitch you could never get aft CG or too forward with any loading combination. Wish I had a CS in the 12 much more than more speed or power. If you don't like a CS for a 9 then you have never flown with one. More than other RVs I think it is a perfect match with the lower horsepower 0-320 and the high lift longer wing.
__________________
Scott- 2017 dues paid
RV-12 #120515, 319RV 155 hours.
1st flight 12/08/15, flew SNF, Oshkosh, Triple Tree & SERFI in year 1!
RV-9A, 536 hours, sold
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 04:38 PM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.