Prop Tune & Engine RPM

Discussion in 'Downeast Engine Room' started by JimRP31, Jun 26, 2018.

  1. Genius

    Genius Captain

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    Jim,

    I have a phototach if you want to borrow it. I'm in Newport.

    EGT is exhaust gas temperature.

    turbocator from Sbmar.com or ISSPRO is the way to go. It really is a great tool for looking at your boost pressure and EGT for problem solving and prop tuning.
     
  2. JimRP31

    JimRP31 Captain

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    Thank you. I may take you up on your offer of a phototach. I will let you know. Jim
     
  3. Tunatown

    Tunatown Senior Member

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    Exhaust gas temp
     
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  4. fortier256

    fortier256 Captain

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    Exhaust Gas Temperature. It is probably the best indicator of load on your engine.
    This is a worthwhile investment.
    SMX Marine Boost & Pyro Gauge Kit
    A good next winter project.
     
  5. BillD

    BillD Captain

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    All you guys who answered "EGT" as a way to "verify" propping/engine load are of course correct.
    I have a SMX EGT gauge/sensor kit on the 370. Running WOT with a full load the EGT on the 370 never exceeds 800F! The engine is definitely detuned.

    And the guys who asked what EGT is....all good...we are all here to help and learn.
     
  6. 05bill

    05bill Captain

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    BillD, you have a 379 Yanmar ?

    850 at wot , the range for the Yanmar 370 is about 1000 to 1150 at cruise , at wot its about 1200 , maybe a little more , per Tony at Seaboard.

    Now I am confused again ?

    Oh I see your running a Cummins 370, now I understand.

    And RP Jim that is interesting, you have a 21, I have a 22, your pitch is 20.8 , mine is 20. When I changed that pitch to 20 from 22, I got 3450 photo tached. I will try it again to see what I get. And Jim, I put a pyrometer in this year , its a great aid, very easy, Seaboard has all the necessary parts for it

    Bill
     
  7. JimRP31

    JimRP31 Captain

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    After the engine work, see (Engine Work) I wanted to see if my WOT had improved. New numbers below. Bottom was clean but not spotless.
    Niemiec said 3300 is an acceptable WOT for my engine.

    Early Summer Fall prior to haul out
    2000 10
    2500 13.9-14 13.7
    2700 15.2 15.5
    2800 16 16.5
    2900 16.8 17.2
    3000 17.6 18.2
    3100 18.3 19
    3200 19 WOT 20
    3300 21 WOT
     
  8. 05bill

    05bill Captain

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    Hi Jim, what is your prop size ? Mine is a 22 x 20, I get 3450 at wot , don't remember speed. I hear Neimec but I would rather see 3400 to 3450. A little under propped.

    Bill
     
  9. JimRP31

    JimRP31 Captain

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    My prop is a 22" reduced to 21' by a previous owner. Pitch is 20.995 based on the prop scan report. I hit something and one blade has a slight bend in it. I am thinking of taking in this winter and have the bend fixed and the prop adjusted to gain 100-150 more RPM.
     

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