Welcome! Becoming a registered user of ShortWingPipers.Org is free and easy! Click the "Register" link found in the upper right hand corner of this screen. It's easy and you can then join the fun posting and learning about Short Wing Pipers!

Page 2 of 2 FirstFirst 12
Results 11 to 18 of 18

Thread: O320 160hp 75% of power

  1. #11
    Pacer42Z's Avatar
    Join Date
    Feb 2008
    Location
    Winchester, VA
    Posts
    589
    Post Thanks / Like

    Default Re: O320 160hp 75% of power

    Quote Originally Posted by Gilbert Pierce View Post
    Manifold pressure on a fixed prop doesn't do much good in my opinion. I removed my MAP gage

    Lycoming says 75% power is at 2450 rpm at sea level. For every 1000 above sea level add 20 rpm. i.e. at 4000' msl you would use 2530 rpm for 75% power. Here is a chart I carry in the airplane.

    Leaning to best power I typically see fuel flows 0.5 to 1.0 gallons per hour less than the chart shows.



    This is great info. I always keep 2,500 RPM, but according to the chart, at higher altitude I’m only running about 65% Power. I’ll try next time if I can get 2,600 RPM with my 58” pitch prop.

    Juergen
    Pacer N3342Z

  2. #12
    Alessandro's Avatar
    Join Date
    Apr 2019
    Location
    ALBENGA - ITALY
    Posts
    121
    Post Thanks / Like

    Default Re: O320 160hp 75% of power

    Quote Originally Posted by Pacer42Z View Post
    This is great info. I always keep 2,500 RPM, but according to the chart, at higher altitude Iím only running about 65% Power. Iíll try next time if I can get 2,600 RPM with my 58Ē pitch prop.

    Juergen
    Pacer N3342Z
    If I remember correctly we miss about 1 inch of MAP every 1000 ft of altitude.




    Sent from my iPhone using ShortWingPipers.Org mobile app

  3. #13
    tloes's Avatar
    Join Date
    Mar 2014
    Location
    Waterloo, IA
    Posts
    405
    Post Thanks / Like

    Default Re: O320 160hp 75% of power

    The 90% rule comes from the rpm-related loading of a "fan". Power is a cubic function of RPM with fans. If you reduce rpm to 90% of maximum, you are also reducing power by 0.9 x 0.9 x 0.9 = 73% of the original power.
    Todd Loes -- Waterloo, IA
    (PA22-150 N3568Z)

  4. #14
    Alessandro's Avatar
    Join Date
    Apr 2019
    Location
    ALBENGA - ITALY
    Posts
    121
    Post Thanks / Like

    Default Re: O320 160hp 75% of power

    Quote Originally Posted by tloes View Post
    The 90% rule comes from the rpm-related loading of a "fan". Power is a cubic function of RPM with fans. If you reduce rpm to 90% of maximum, you are also reducing power by 0.9 x 0.9 x 0.9 = 73% of the original power.
    Thank you!


    Sent from my iPhone using ShortWingPipers.Org mobile app

  5. #15

    Join Date
    Oct 2018
    Location
    West Arkansas
    Posts
    215
    Post Thanks / Like

  6. #16
    Alessandro's Avatar
    Join Date
    Apr 2019
    Location
    ALBENGA - ITALY
    Posts
    121
    Post Thanks / Like

    Default Re: O320 160hp 75% of power

    Quote Originally Posted by Pacer42Z View Post
    This is great info. I always keep 2,500 RPM, but according to the chart, at higher altitude I’m only running about 65% Power. I’ll try next time if I can get 2,600 RPM with my 58” pitch prop.

    Juergen
    Pacer N3342Z
    Juergen, at 2500 rpm and about 2000 ft, which speed you have with 58" prop? Your N3342Z is it a Tripacer? Thank you.

  7. #17
    Pacer42Z's Avatar
    Join Date
    Feb 2008
    Location
    Winchester, VA
    Posts
    589
    Post Thanks / Like

    Default Re: O320 160hp 75% of power

    Quote Originally Posted by Alessandro View Post
    Juergen, at 2500 rpm and about 2000 ft, which speed you have with 58" prop? Your N3342Z is it a Tripacer? Thank you.
    Alessandro, you gave me the perfect excuse not to work in the garden today and rather go flying. Attached are pictures at 2,000 feet, 3,000 feet and 6,500 feet each showing the indicated and true airspeed running the engine at 2,500 RPM. My airplane is a converted Tri-Pacer with 160 HP. I also have many other modifications on it. Here is a link to a YouTube video showing my Pacer: https://www.youtube.com/watch?v=OktsmuHiWKM . In most of my videos on my YouTube channel I keep one camera on the instrument panel, so you can see more different altitudes and OATs and I almost always run 2,500 RPM. However, in some of the videos I have my 6.00x6 tires with wheel pants and some videos I have 22" Desser tires. They slow me down by about 4 to 5 knots.

    I'm afraid though, it will not give you a direct comparison to your Tri-Pacer.

    Juergen
    Pacer N3342Z
    Attached Images Attached Images

  8. #18
    Alessandro's Avatar
    Join Date
    Apr 2019
    Location
    ALBENGA - ITALY
    Posts
    121
    Post Thanks / Like

    Default Re: O320 160hp 75% of power

    Quote Originally Posted by Pacer42Z View Post
    Alessandro, you gave me the perfect excuse not to work in the garden today and rather go flying. Attached are pictures at 2,000 feet, 3,000 feet and 6,500 feet each showing the indicated and true airspeed running the engine at 2,500 RPM. My airplane is a converted Tri-Pacer with 160 HP. I also have many other modifications on it. Here is a link to a YouTube video showing my Pacer: https://www.youtube.com/watch?v=OktsmuHiWKM . In most of my videos on my YouTube channel I keep one camera on the instrument panel, so you can see more different altitudes and OATs and I almost always run 2,500 RPM. However, in some of the videos I have my 6.00x6 tires with wheel pants and some videos I have 22" Desser tires. They slow me down by about 4 to 5 knots.

    I'm afraid though, it will not give you a direct comparison to your Tri-Pacer.

    Juergen
    Pacer N3342Z
    Thank you very much!!
    Your Ď22/20 is very fast!!
    And you have a very good panel!

    I think that tricycle will be at least 5 knots slower.
    But the speed isnít really important for me, just curiosity, the problem is that I havenít yet the permit to fly and I can only imagine everything...........

    Now I watch all your videos!!




    Sent from my iPhone using ShortWingPipers.Org mobile app

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •