A method developed in SAE 2019-01-0058 to correctfor deviations from quasi-steady exhaust valve flow isimplemented on a single-cylinder GT-Power modeland the effects on pumping work and blowdown pulsecharacteristics are investigated. The valve flow area isalways reduced compared to the referencequasi-steady case. It decreases with higher pressureratios over the valve and increases with higherengines speeds. The reduced flow area increasespumping work with load and engine speed, thoughprimarily with engine speed. The magnitude of theblowdown pulse is reduced and the peak is shifted toa later crank angle.