VARIABLE VALVE ACTUATION CONTROLS FOR ENGINES

A system includes an engine including a valvetrain comprising one or more intake valves and one or more exhaust valves, a variable valve actuation (VVA) system electronically controllable to vary operation of the valvetrain to selectably operate the engine in either a Miller cycle or a non-Miller cycle, and an electronic control system configured to control the VVA system to change operation of the engine from the Miller-cycle to the non-Miller cycle if an engine speed condition is satisfied, a peak cylinder pressure (PCP) condition is satisfied, at least one of an air-fuel ratio (AFR) condition and an oxygen-fuel-control (OFC) condition is satisfied, and a minimum off time condition for the VVA system is satisfied.