torque, and displaces 2000 cm3=2 dm3=0.002 m3: We also get the megapascal figure if we use cubic centimetres for : Power from MEP and crankshaft speed If we know the crankshaft speed, we can also determine the engine's power output from the MEP figure: In our example, the engine puts out 160 N·m of torque at 3600 min−1: As piston engines usually have their maximum torque at a lower rotating speed than the maximum power output, the BMEP is lower at full power (at higher rotating speed). If the same engine is rated 76 kW at 5400 min−1 = 90 s−1, and its BMEP is 0.844 MPa, we get the following equation: Types of mean effective pressures Mean effective pressure (MEP) is defined by the location measurement and method of calculation, some commonly used MEPs are given here. Brake mean effective pressure (BMEP) - Mean effective pressure calculated from measured brake torque. Gross indicated mean effective pressure (IMEPg) - Mean effective pressure calculated from in-cylinder pressure over compression and expansion portion of engine cycle (360° in a four-stroke, 180° in a two-stroke). Direct measurement requires cylinder pressure sensing equipment. Net indicated mean effective pressure (IMEPn) - Mean effective pressure calculated from in-cylinder pressure over the complete engine cycle (720° in a four-stroke, 360° in a two-stroke). Direct measurement requires cylinder pressure sensing equipment. Pumping mean effective pressure (PMEP) - Mean effective pressure from work moving air in and out of the cylinder, across the intake and exhaust valves. Calculated from in-cylinder pressure over intake and exhaust portions of engine cycle (360° in a four-stroke, 0° in a two-stroke). Direct measurement requires cylinder pressure sensing equipment. PMEP = IMEPg - IMEPn. Friction mean effective pressure (FMEP) - Theoretical mean effective pressure required to overcome engine friction, can be thought of as mean effective pressure lost due to friction. Friction mean effective pressure calculation requires accurate measurement of cylinder pressure and dynamometer brake torque. FMEP = IMEPn - BMEP. BMEP typical values See also Compression ratio Notes and references Notes References External links Brake Mean Effective Pressure (bmep), Power and Torque, Factory Pipe All About Mean Effective Pressure, Harleyc.com Tiddler steam engine Piston engines Engine technology