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Engine Pressure

  1. Apr 28, 2008 #1
    I was wondering if anyone could tell me or show me how to calculate the pressure inside the cumbustion chamber of a Briggs and Stratton 5hp engine. This calculation is done at 3800 rpm. Thanks

  2. jcsd
  3. Apr 28, 2008 #2


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    This is a complex question, and the pressure doesn't stay constant at any point during the combustion cycle.

    Mean Effective Pressure is calculated by:

    MEP = 1000 * (P * Nr) / (V * N)

    Where MEP is in kPa, P is power in kW, Nr is the number of crank revolutions per power stroke, V the displaced volume per cylinder, and N the number of cylinders.

    Note that the peak cylinder pressure will be much higher than this, but the calculation of this is far more involved.
  4. Apr 28, 2008 #3
    Thanks a lot this will really help with what we are doing

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