Method for 3-step variable valve actuation

Abstract

A method of variably actuating a valve of an engine includes selecting one of three valve lift profiles dependent at least in part upon engine operating conditions and parameters. The selected valve lift profile is phased relative to the angular position of the engine crankshaft dependent at least in part upon engine operating conditions and parameters. The valve is actuated according to the selected and phased valve lift profile.

1 . A method of variably actuating a valve of an engine, said engine having a crankshaft, at least one intake valve and at least one exhaust valve, a camshaft associated with said valves, said method comprising: 
 selecting an intake valve lift profile dependent at least in part upon engine operating conditions and parameters, wherein said selecting step comprises placing a three-step valve actuating device into one of a low-lift, mid-lift and high-lift operating mode wherein the three-step valve actuating device is actuated by a corresponding one of a low-lift, mid-lift and high-lift cam lobe of the engine camshaft;    phasing the selected intake valve lift profile relative to the angular position of the engine crankshaft by substantially fully retarding the intake valve opening;    phasing the lift profile of the at least one exhaust valve associated with the same cylinder as the at least one intake valve by advancing the exhaust valve opening, to thereby enter a cold start operating mode; and    actuating the at least one intake valve according to the selected and phased intake valve lift profile.    
   
   
       2 . (Cancelled)  
   
   
       3 . (Cancelled)  
   
   
       4 . The method of  claim 1 , wherein said phasing the selected intake valve lift profile step comprises advancing the intake valve opening, and said phasing the lift profile of the at least one exhaust valve comprises substantially fully advancing