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  #1  
Old 12-14-2017, 03:57 PM
nightflier nightflier is offline
 
Join Date: Jan 2005
Location: Cincinnati
Posts: 66
Default Percent power vs RPM

Trying to establish percent power for POH for RV9A, with 160 HP Catto prop. ANy ideas?
Thanks,
Sam
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  #2  
Old 12-14-2017, 04:32 PM
moosepileit moosepileit is offline
 
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http://www.vansairforce.com/communit...hp?t-8037.html searched for thread.

Searched for a Lyc image, I know the rpm is probably too low for a Catto.
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Last edited by moosepileit : 12-14-2017 at 04:38 PM.
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  #3  
Old 12-14-2017, 04:55 PM
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vlittle vlittle is offline
 
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Quote:
Originally Posted by nightflier View Post
Trying to establish percent power for POH for RV9A, with 160 HP Catto prop. ANy ideas?
Thanks,
Sam
Search the forums "Engine Power Percentage?"
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  #4  
Old 12-14-2017, 05:10 PM
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sirlegin sirlegin is offline
 
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Location: Keller, Texas
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Here's what I use in my 9A 160HP Catto 3 blade

POWER SETTING PERCENTAGE
RPM X 100 + MP (INCHES)
60=100%
57=95%
51=85%
48=75%
45=65%
42=60%
39=55%
36=50%
33=45%
30=40%
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  #5  
Old 12-14-2017, 05:28 PM
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RV8JD RV8JD is offline
 
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Quote:
Originally Posted by sirlegin View Post
Here's what I use in my 9A 160HP Catto 3 blade

POWER SETTING PERCENTAGE
RPM X 100 + MP (INCHES)
60=100%
57=95%
51=85%
48=75%
45=65%
42=60%
39=55%
36=50%
33=45%
30=40%
I think you meant RPM/100 + MP.

Example: 2450/100 + 23.5 = 48 is approximately 75% power.
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RV-8, 370 Tach Hours
(Pic 1),(Pic 2)
- Out with the Old, In with the New
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RV-8, 1938 Tach Hours (Pic 1),(Pic 2) - Sold

Glasflügel Standard Libelle 201B, N564NS - Sold
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  #6  
Old 12-14-2017, 05:55 PM
brad walton brad walton is offline
 
Join Date: Jul 2007
Location: Cypress, TX
Posts: 489
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Originally saw the manifold pressure plus rpm formula from the RVator. But I doubt its accuracy. I can run 24/24 at low altitude burning 9 gph. I don't think I'm getting 75% power at less than 10.5 to 11 gph
Mine is an io 360

Last edited by brad walton : 12-14-2017 at 06:15 PM. Reason: Add text re displacement
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  #7  
Old 12-14-2017, 06:04 PM
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RV8JD RV8JD is offline
 
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Quote:
Originally Posted by brad walton View Post
Originally saw the manifold pressure plus rpm formula from the RVator. But I doubt its accuracy. I can run 24/24 at low altitude burning 9 gph. I don't think I'm getting 75% power at less than 10.5 to 11 gph
Note the Lycoming power chart in Post #2 above. At SL, 2400 RPM and 24" MP equals 75% power at approximately 10 GPH.

Note that the % Power approximation is not valid for LOP ops.
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Carl N.
Arlington, WA (KAWO)
RV-8, 370 Tach Hours
(Pic 1),(Pic 2)
- Out with the Old, In with the New
(Pic)
RV-8, 1938 Tach Hours (Pic 1),(Pic 2) - Sold

Glasflügel Standard Libelle 201B, N564NS - Sold
Rolladen-Schneider LS1-f, N61MP - No longer owned

Last edited by RV8JD : 12-14-2017 at 06:20 PM.
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  #8  
Old 12-15-2017, 07:20 AM
Rupester Rupester is offline
 
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Location: Mahomet, Illinois
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The GRT EFIS installation manual just happens to have a MP-RPM-%power chart for an O-320. It's used to set up the EFIS for display of % power. I don't have access to my install manual at present, but I think you can access it at GRTs website under "documentation".
When I was doing the setup for mine, that was the best &clearest reference I found for % power. Further, when I checked it matched those mind-boggling Lyco graphs perfectly.
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  #9  
Old 12-15-2017, 12:15 PM
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sirlegin sirlegin is offline
 
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Quote:
Originally Posted by RV8JD View Post
I think you meant RPM/100 + MP.

Example: 2450/100 + 23.5 = 48 is approximately 75% power.
I'm glad you were paying attention. Thanks
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  #10  
Old 12-16-2017, 12:32 PM
nightflier nightflier is offline
 
Join Date: Jan 2005
Location: Cincinnati
Posts: 66
Default O320 % power

Thanks for you help guys, VAF comes through again!
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