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Mechanical efficiency of IC engine

  1. Sep 21, 2006 #1
    what is the equation for the mechanical efficiency of an internal combustion engine?

    what are the formulas for 'ip' for 4-stroke and 2-stroke engines?
    thank you
  2. jcsd
  3. Sep 22, 2006 #2


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    Mechanical efficiency n:

    n = (Pb / Pig) = 1-(Pf / Pig)

    Where Pb is the brake power, Pig is gross indicated power, and Pf the friction power.

    What do you mean by ip? Indicated pressure?
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