Abstract: A valve lifter has a lifter body with a first surface arranged to feet on a pair of low lift cams on a camshaft, and a pair of hydraulic slides disposed in a bore of the lifter body. The slides have a stored position wherein they define therebetween and within the bore a chamber arranged to allow entry of a high lift cam on the camshaft disposed between the pair of low lift cams. The lifter body is formed with a window opening to the chamber to allow access of the high lift cam to the chamber. The slides have an operative position wherein they define a second surface opposite to the window arranged to rest on the high lift cam.