Horse power versus revs

Discussion in 'Diesel Engines' started by Mik the stick, Dec 19, 2012.

  1. Mik the stick
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    Mik the stick Senior Member

    A John Deere engine gives 175hp@2400revs. Torque changes with revs so although I can work out torque at Max revs I cant work out HP at say 2000 revs or tick over speed. is there a formula or rule of thumb for this
     
  2. TANSL
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    TANSL Senior Member

    Take a look at the catalog of the engine, where, sure, you'll find the curve hp / rpm thereof. Not all things are reduced to formulas.
     
  3. jonr
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    jonr Senior Member

    Agreed, it varies widely with the engine.
     
  4. Landlubber
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    Landlubber Senior Member

    all engine makers release specs and graphs so you can work it out.
     
  5. liki
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    liki Senior Member

    Torque is the force the engine is capable to produce, and power the amount of work it can perform during a fixed period of time. Add the time period and the amount of work performed equals power multiplied by time.

    Power, in this case, equals rotational speed multiplied by torque. And there's also a constant involved, depending on the units you are using.
     
  6. TANSL
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    TANSL Senior Member

    Or I'm wrong a lot and I've forgotten everything I knew about physics, or Torque = force times distance.
    If I'm wrong, I apologize for confusing customers.
     
  7. Ad Hoc
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    Ad Hoc Naval Architect

    There should be a simple curve showing how the 2 vary.

    Otherwise:-

    Power = Torquex RPMx2xPi/60
     
  8. liki
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    liki Senior Member

    That is naturally correct, I simplified things a little. Debating about the effect of engine torque and power to acceleration has taught me that it is usually the best way. ;>
     
  9. Frosty

    Frosty Previous Member

    Tick over speed = Idle.
     
  10. DCockey
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    DCockey Senior Member

    Torque about a point equals force times distance from the line of action of the force to the point.

    Energy equals force times the distance it is applied for.

    It is confusing.
     
  11. Frosty

    Frosty Previous Member

    Confusing ?--- A Horse power is the amount of work a horse can do.

    A 300HP vette can do as much work as 300 horses,---big ones.

    Thats about 150 bollard tons.
     
  12. michael pierzga
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    michael pierzga Senior Member

    Gee...what about a Seagull outboard engine ? it can do as much work as 3 seagulls ?

    Im confused
     
  13. Frosty

    Frosty Previous Member

    Ive never seen a seagull do any work.
     
  14. michael pierzga
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    michael pierzga Senior Member

    And my old segull is used in the local bar as a bar stool................
     

  15. pistnbroke
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    pistnbroke I try

    can I have a photo of that seagull bar stool ..the Saving old seagulls forum has been having an internal war of late and something like that would be calming. Unfortunatly it did not self destruct ,,
     
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