Systems, devices, and methods are disclosed that during cylinder deactivation, including skipfire, at low engines speeds and low engine loads maintain adequate oil pressure of valvetrain components or hardware required for CDA and/or skipfire operation.

Methods and systems are provided for oil flow for a variable displacement engine of a vehicle. In one example, a system may include an engine having a plurality of deactivatable cylinders capped by a cylinder head, an oil supply passage formed in the cylinder head and joined to a first oil inlet, deactivatable hydraulic lash adjusters (HLAs) arranged along a flow path of the oil supply passage, and a primer filter disposed within the cylinder head and fluidly coupling the oil supply passage to a second oil inlet. Oil may flow through the primer filter to the oil supply passage to maintain a flow rate of oil through the oil supply passage above a pre-determined flow rate.

A fuel pump includes a camshaft that rotates in accordance with operation of an engine and a tappet provided in contact the camshaft. An ECU includes an angle determination unit configured to determine whether a rotation angle from a start of rotation of the camshaft when starting the engine is under a predetermined angle required for forming an oil film on a sliding portion of the tappet, and a control unit configured to, when the rotation angle from the start of rotation of the camshaft is determined to be under the predetermined angle, execute a limit process including at least one of limiting a fuel discharge pressure of the fuel pump or limiting a rotation of the camshaft.

A cam follower assembly is provided including an improved lubricant flowpath. The assembly includes a generally cylindrical housing including an annular groove adapted to be in communication with a lubricant gallery in an engine block or cylinder head. An axial end of the housing includes skirt portions including openings, and one of the skirt portions includes a first recessed section indented from an outer lateral surface of the housing and extending axially between the annular groove and a respective one of the openings. A pin is mounted in the openings of the skirt portions and has a second recessed section indented from an outer lateral surface of the pin that extends to at least one of the ends of the pin. The second recessed section is in communication with the first recessed section, and a cam roller supported on the pin.

An engine roller lifter for use in a valve train of an internal combustion engine includes a body, an anti-rotation device and a clip. The body can have an outer peripheral surface configured for sliding movement in a bore provided in the engine. The body can define a receiving channel formed in the outer peripheral surface. The body can further define a slot formed at the receiving channel. The anti-rotation device can include a guide plug received in the receiving channel of the body. The guide plug can extend outwardly from the outer peripheral surface of the body. The guide plug can be configured to locate into a bore slot defined in a cylinder head of the internal combustion engine. The clip can be received by the slot and captured the guide plug in the receiving channel.

Systems and methods for intermittent supply of lubricating oil to a tip of a rocker arm assembly. In one embodiment, a lubricating oil may be selectively to a tip of a rocker arm via oil channels aligned only during opening of a valve coupled to the tip.

A supply pump includes a housing that has a tappet receiving chamber, which receives a plunger drive mechanism, and oil for lubricating respective lubricating portions of the plunger drive mechanism is temporarily retained in the tappet receiving chamber. In the housing, a communication hole opens in an inner peripheral wall surface of a tappet guide and guides the oil from a tappet upper side chamber into a tappet lower side chamber at the time of upwardly moving a tappet.

A tubular structure comprises a first end and a second end, a cylindrical outer structure, and at least one inner cavity defined by the cylindrical outer structure and the first and second ends. The first and second ends each include a recess and a cap press fit within the recess. The caps provide a connection point for the ends of the tubular structure. Each end includes a vent in fluid communication with the inner cavity during manufacturing of the tubular structure, prior to insertion of the caps. An isotropic internal support structure extends longitudinally between the ends within the cylindrical outer structure and defines an oil flow channel extending through the tubular structure, each cap includes a cap orifice aligned with the oil flow channel, and the cylindrical outer structure, the first and second ends, and the internal support structure are continuously and unitarily formed.

Systems and methods for intermittent supply of lubricating oil to a tip of a rocker arm assembly. In one embodiment, a lubricating oil may be selectively to a tip of a rocker arm via oil channels aligned only during opening of a valve coupled to the tip.

According to one aspect of the present invention, a sliding member includes: a sliding surface against which an outer surface of a cam abuts; and a groove having a spiral shape or a plurality of grooves having an annular shape, which are provided on the sliding surface. The sliding surface includes a central region having a circular shape and including a center of the sliding surface, and a first annular region located outside the central region. A ratio R.sub.C of a width L2 of the groove to a pitch L1 of the groove in the central region is larger than a ratio R.sub.O1 of the width L2 of the groove to the pitch L1 of the groove in the first annular region.