Patent ID: 8235012

Claim:
Method for operating an internal combustion engine including variable cam phasing mechanisms and multi-step valve lift mechanisms operative to control phase and lift of intake and exhaust valves, the internal combustion engine selectively operative in a first combustion mode and a second combustion mode, the method comprising: commanding transitioning engine operation from the first combustion mode to the second combustion mode; adjusting phasings of the intake valves and the exhaust valves corresponding to a first intake air cylinder volume and a first residual gas cylinder volume; switching magnitude of lift of one of the intake valves and the exhaust valves corresponding to the second combustion mode; adjusting phasings of the intake valves and the exhaust valves corresponding to a second intake air cylinder volume and a second residual gas cylinder volume; switching magnitude of lift of the other of the intake valves and the exhaust valves corresponding to the second combustion mode; and adjusting phasings of the intake valves and the exhaust valves corresponding to a preferred intake air cylinder volume and a preferred residual gas cylinder volume for operating in the second combustion mode.