A system for monitoring operation of an internal combustion engine having a rocker arm assembly for actuating an engine valve is disclosed. The rocker arm assembly includes a first arm with a first end and a second end, at least one slider pad connected to the first arm near the second end of the first arm, a second arm also having a first end pivotally connected near the first end of the first arm along a pivot axle, a latch that when latched secures the first arm relative to the second arm in a latched mode, and when unlatched allows the first arm to move relative to the second arm in an unlatched mode. The system also employs a sensor attached to one of the arms that can detect when the arms are moving relative to each other, and adapted to provide a signal indicating the detected movement.

A rocker arm assembly constructed in accordance to one example of the present disclosure includes an outer rocker arm and an inner rocker arm. The outer rocker arm has a first roller configuration that rotates around a first axis. The inner rocker arm has a second roller configuration that rotates around a second axis. The inner rocker arm is configured to move between a latched and unlatched position relative to the outer rocker arm. One of the first and second axes is positioned for alignment over an engine valve. The other of the first and second axes is offset from the engine valve.

A hydraulic lash adjuster assembly constructed in accordance to one example of the present disclosure includes a bucket and a hydraulic lash adjuster. The hydraulic lash adjuster is received in the bucket and has a body, a leakdown plunger and a socket. The leakdown plunger is received in the body. The socket is received by the leakdown plunger. The socket and leakdown plunger define a reservoir therebetween. The socket includes a gravity feed arrangement to feed fluid to the reservoir of the leakdown plunger.

It is described herein a hydraulic lifter for an internal combustion engine. The hydraulic lifter may comprise a lifter body, a self-contained hydraulic cartridge, a pushrod seat, and a retaining clip. The self-contained hydraulic cartridge may be disposed within a cartridge bore in the lifter body. The self-contained hydraulic cartridge may comprise a self-contained hydraulic system such that a lifter piston of the hydraulic system is not directly disposed within a bore in the lifter body.

A valve train assembly for an internal combustion engine includes: a dual body rocker arm for controlling a valve of a cylinder, the rocker arm including a first body, a second body mounted for pivotal motion with respect to the first body, a first biasing means, and a latch pin moveable between a first position in which the latch pin latches the first body and the second body together and a second position in which the first body and the second body are un-latched to allow pivotal motion of the second body relative to the first body; and an actuator arrangement external to the dual body rocker arm and drivable by an actuation source, the actuator arrangement moving the latch pin from one of the first position and the second position to the other of the first position to the second position.

Methods and systems are provided for oil flow for hydraulic lash adjusters of a vehicle engine. In one example, an engine cylinder bank includes a plurality of deactivatable hydraulic lash adjusters and a plurality of non-deactivatable hydraulic lash adjusters. A first linear oil supply passage and a second linear oil supply passage are formed within the cylinder bank and extend linearly through the cylinder bank without bends or curvature to the deactivatable and non-deactivatable hydraulic lash adjusters, with the deactivatable and non-deactivatable hydraulic lash adjusters having a same length.

A valve train assembly includes: a first group of one or more dual body rocker arms and a second group of one or more dual body rocker arms, the first group for controlling one or more valves of a first cylinder and the second group for controlling one or more valves of a second cylinder, each of the dual body rocker arms including a first body, a second body, and a latching arrangement for latching and unlatching the first body and the second body; and an actuator arrangement external to the dual body rocker arms for controlling the latching arrangement, the actuator arrangement including a shaft having a first set of one or more cams for controlling the latching arrangements of the first group of one or more dual body rocker arms and a second set of one or more cams for controlling the latching arrangements of the second group.

A method of operating a rocker arm assembly in a cylinder deactivation mode according to one example of the present disclosure includes providing a two-step variable valve lift rocker arm assembly and a deactivating lash adjuster. Operation of the rocker arm assembly in cylinder deactivation mode is selected. The rocker arm assembly is operated in low-lift mode based on the selection of the cylinder deactivation mode. Subsequent to or concurrently with operating the rocker arm assembly in the low-lit mode, the deactivating lash adjuster is operated in the unlatched mode. A first amount of the total lost motion required for cylinder deactivation mode is accounted for by lost motion of the rocker arm assembly operating in the low-lift mode and a remainder amount of the total lost motion is accounted for by lost motion of the deactivating lash adjuster operating in the unlatched mode.

A rocker arm assembly constructed in accordance to one example of the present disclosure includes an outer rocker arm and an inner rocker arm. The outer rocker arm has a first roller configuration that rotates around a first axis. The inner rocker arm has a second roller configuration that rotates around a second axis. The inner rocker arm is configured to move between a latched and unlatched position relative to the outer rocker arm. One of the first and second axes is positioned for alignment over an engine valve. The other of the first and second axes is offset from the engine valve.

A rocker arm assembly constructed in accordance to one example of the present disclosure includes an outer rocker arm, a first inner rocker arm, and a second inner rocker arm. The first inner rocker arm is configured to move between a latched and unlatched position relative to the outer rocker arm. The second inner rocker arm is configured to move between a latched and unlatch position relative to the outer rocker arm. The rocker arm assembly provides at least three distinct lift profiles including (i) a first lift profile when the first inner rocker arm is latched and the second inner rocker arm is unlatched, (ii) a second lift profile when the second inner rocker arm is latched and the first inner rocker arm is unlatched, and (iii) a third lift profile when both the first and second inner rocker arms are unlatched.