1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

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


    User Avatar
    Science Advisor
    Gold Member

    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

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook