Brake Mean Effective PressureEngineering Term & Method of Comparing All Engines
BMEP-PSI = Average Cylinder Pressure in PSI
Two Stroke -- BMEP = HP x 6500 / L x RPM Four Stroke -- BMEP = HP x 13000 / L x RPM L = Displacement in Litres (80 cc = .08 Litres) (700 cc = .7 Litres) Note: 3% Loss of HP & Air Density -- each 1000 ft. of Elevation Above Sea Level Examples: 1000 T- Cat 166 hp @ 8400 rpm Ported T Cat ~ Exhaust TA (time area) = 155.6 BMEP @ 8400 rpm 700 Yamaha Mtn. Max 140 hp @ 8200 rpm 982 SRX Union Bay 211 hp @ 8900 rpm Good way to compare engine volumetric efficiency. Engine compression in psi plus pipe working at 110% may? come close to BMEP. If your BMEP is not higher than your compression psi -- you have a problem. Snowmobile Guidelines: Less than 160 BMEP = 92 octane Pump Gas Quality WorkmanshipContact Me Here
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