Exhaust valve opening (EVO)Intake valve opening (IVO)
HI You answered it your self... exhaust valve opening (EVO) is when the exhaust valve opens.. and the same for the intake (IVO).. When the EVO happens the motor pushes the exhaust (burnt fuel) out of the motor when the IVO happens it sucks gas into the motor to get burned and make power.. Exampe of a 4 strock motor. 1) piston goes down , sucking in air and fuel (IVO) 2) piston goes up compressing the air and fuel spark plug fires ignighting the fuel 3) piston goes down turning the crank powering the car from the explosion of Fuel. 4) piston goes back up pushing the spent fuel out. (EVO) then repeats. On a 4 cylinder car this happens 4 different times on an 8 cylinder car 8 different times and on 6 cylinder car 6 different times. When one cylender is firing another well be coming up to push out its spent fuel and another well be going down drawing in fuel and so forth.. good luck tim EDIT IVC = intake valve closes EVC= exhaust valve closes
