A roller hydraulic valve lifter includes a body having a longitudinal central axis and an interior area defined by an inside surface which has a pair of flat surfaces opposite one another and connected by a pair of walls. A first bore, essentially perpendicular to the longitudinal axis, extends through the flat surfaces. A bearing is disposed partially in the interior area. The bearing includes an outer ring having substantially cylindrical exterior and interior bearing surfaces. A shaft extends through the first bore and the outer ring and between the pair of flat surfaces. A plurality of needle rollers is disposed between and rollingly engage the shaft and the cylindrical inner bearing surface. The shaft and the plurality of needle rollers are manufactured from an AISI 52100 alloy steel that is carbo-nitrided. The shaft and the plurality of needle rollers have a surface hardness of a minimum of HRc 65.

An internal combustion engine is provided, which includes an engine body provided with a cylinder having openings for intake and exhaust, and valve bodies that open and close the openings, cam shafts, each provided with a cam lobe that depress the corresponding valve body to open the openings, and bearing members pivotally supporting the cam shaft via lubricating oil. The cam shaft includes cam journals pivotally supported by the bearing members, and a recess formed at a position of the cam journal, opposing the cam lobe in the circumferential direction, and depressed radially inwardly of the cam journal, the recess being deeper in an axial end part of the cam journal than an axial center part.

Side surfaces of an end cam cap and a pair of side surfaces of a recess for cam cap form two cross-sectional area gradually changing gaps therebetween. A gasket is filled between an inner surface of the recess for cam cap and an outer surface of the end cam cap. The inner surface includes the side surfaces of the recess for cam cap and the outer surface includes the side surfaces of the end cam cap.

Systems and methods for operating an engine with an oil pump that supplies engine oil to various oil consumers in an engine are presented. In one example, a displacement of a variable displacement engine oil pump is adjusted to provide sufficient oil pressure throughout the engine, but low enough to conserve fuel.

Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, estimates of engine fuel consumption for operating the engine with a plurality of cylinder modes or patterns while a transmission is engaged in different gears are determined and are used as a basis for deactivating engine cylinders.

Systems and methods for operating an engine with deactivating valves are presented. In one example, deactivated valves may be reactivated to increase a rate of camshaft phase indexing relative to engine crankshaft position. However, if a desired rate of camshaft indexing is low, the engine cylinders may remain deactivated based on the low rate of desired camshaft indexing.

Systems and methods for operating an engine with deactivating valves are presented. In one example, a groove in a camshaft controls oil flow to a valve operator that selectively activates and deactivates a poppet valve of a cylinder. The groove moves with the camshaft so that oil delivery to the valve operator is timed properly to deactivate and reactivate the cylinder.

Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, valves of a cylinder are deactivated in a closed state in response to an indication of degradation of a valve of the cylinder. Further, fuel flow to the cylinder may be stopped via ceasing to inject fuel to the cylinder.

Systems and methods for operating an engine with deactivating and non-deactivating valves is presented. In one example, the engine may include non-deactivating intake valves, deactivating intake valves, and only non-deactivating exhaust valves. The non-deactivating exhaust valves may operate to open and close during an engine cycle while deactivating intake valves remain closed during the engine cycle to prevent air flow through selected engine cylinders.

Provided is a V engine which uses common cylinder heads, and permits favorable arrangement of oil passages so as to accommodate various oil regulating features that are required to operate valve property varying mechanisms. Each end of each cylinder head is formed with a plurality of distribution oil passages opening out at an upper surface of the cylinder head for supplying oil pressure from a main gallery to a valve actuating mechanism. A pair of oil passage connecting members internally defining mutually different connecting oil passages are attached to the upper surfaces of the corresponding end parts of the respective cylinder heads.