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OK,

 

I have searched and read about every post I can find regarding setting a ground adj. prop.

I get the jest that a setting that gives 5500-5600rpm S/L @ WOT and 1750-1800 idle seems to be the sweet spot by consensus.

I started trying to dial my prop in for better performance as I was getting 5750-5800rpm S/L @ WOT, spinning my wheels so-to-speak.

I re-pitched it to get 5550rpm S/L @ WOT but now my climb rpm seems low 4850-4950rpm.

My cruse speed went up which was great, but I don't want to hurt the engine with too low an rpm in the climb out.

I know that Roger says to set the top and bottom and the rest will fall in place but is 4850-4950 too low for a climb rpm?

 

Thanks

Dan

  • Re: 912uls Climb RPM

    by » 4 years ago


     Joe, the service manager at Lockwood Aviation says minimum 5200 rpm static on the ground brakes locked as a rule of thumb.


  • Re: 912uls Climb RPM

    by » 4 years ago


    You need to decide if you want Max cruise speed or Max rate of climb.

    "5750-5800rpm S/L @ WOT" is a Max Cruise setting.

    Actually 5500rpm S/L @ WOT would be the ideal setting if "Getting There" quickly is the goal. (Racing?)

    You will need to climb at a shallower angle at a higher airspeed to prevent lugging the engine as you have already observed.

     

    5800rpm at Vy will give you Max Climb performance. (Limited to 5 minutes.)

    If you normally reduce the throttle for the cruise this would be the choice.

    At this setting, you will over-rev at cruise and descent and will need to be observant.

    A 5500rpm cruise will still be possible at a slightly reduced power setting.

    This "Climb" setting is easier on the engine overall and may save you one day when you need to clear the top of something in a hurry.

     


    Bill Hertzel
    Rotax 912is
    North Ridgeville, OH, USA
    Clicking the "Thank You" is Always Appreciated by Everyone.


    Thank you said by: RotaxOwner Admin, Gordon Rose

  • Re: 912uls Climb RPM

    by » 4 years ago


    I wish someone who knows this stuff could make up a chart for setting the prop?


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