An engine braking system includes a camshaft, a follower, an exhaust armature, a lever, and a hydraulically actuated piston. The camshaft includes at least one cam. The cam has a lobe and a brake bump. The follower engages the cam. The exhaust armature is coupled to the follower. The lever is coupled to the exhaust armature. The hydraulically actuated piston moves the lever. Hydraulic actuation of the piston causes a change in lash distance between the cam and the follower. In an engine brake mode, the follower contacts the cam throughout rotation of the cam.

An engine braking system includes a camshaft, a follower, an exhaust armature, a lever, and a hydraulically actuated piston. The camshaft includes at least one cam. The cam has a lobe and a brake bump. The follower engages the cam. The exhaust armature is coupled to the follower. The lever is coupled to the exhaust armature. The hydraulically actuated piston moves the lever. Hydraulic actuation of the piston causes a change in lash distance between the cam and the follower. In an engine brake mode, the follower contacts the cam throughout rotation of the cam.

A type III rocker arm assembly operable in a first mode and a second mode based on rotation of a cam shaft includes a rocker shaft and a first rocker arm assembly. The first rocker arm assembly receives the rocker shaft and is configured to rotate around the rocker shaft in the first mode based on engagement with the first cam lobe. The first rocker arm assembly collectively comprises a valve side rocker arm, a cam side rocker arm and a latch pin. The valve side rocker arm defines a valve side rocker arm bore. The cam side rocker arm defines a cam side rocker arm bore. The latch pin assembly is received by the valve and cam side rocker arm bores and selectively couples the valve side rocker arm and the cam side rocker arm for concurrent movement in the first mode.

A type III rocker arm assembly operable in a first mode and a second mode based on rotation of a cam shaft includes a rocker shaft and a first rocker arm assembly. The first rocker arm assembly receives the rocker shaft and is configured to rotate around the rocker shaft in the first mode based on engagement with the first cam lobe. The first rocker arm assembly collectively comprises a valve side rocker arm, a cam side rocker arm and a latch pin. The valve side rocker arm defines a valve side rocker arm bore. The cam side rocker arm defines a cam side rocker arm bore. The latch pin assembly is received by the valve and cam side rocker arm bores and selectively couples the valve side rocker arm and the cam side rocker arm for concurrent movement in the first mode.

An exhaust valve rocker arm assembly operable in a combustion engine mode and an engine decompression mode, the exhaust valve rocker arm assembly selectively opening first and second exhaust valves and including a rocker shaft, exhaust valve rocker arm assembly and a ball engine decompression mechanism. The exhaust valve rocker arm assembly has an exhaust rocker arm that receives the rocker shaft and is configured to rotate around the rocker shaft. The ball engine decompression mechanism is configured on the exhaust rocker arm and selectively actuates a valve plunger causing an exhaust valve to perform engine decompression. The ball engine decompression mechanism includes a capsule assembly having a capsule, a biasing member and a ball. The capsule has a cylindrical body that extends between a first end having an actuation face and a second end having a spring return face.

Systems and methods for managing excessive intake flow path pressure and counter flow are implemented to support enhanced engine braking applications, such as 2-stroke or 1.5-stroke engine braking implementations where the intake flow path may be exposed to excessive transient pressures in the combustion chamber during activation or deactivation of an engine brake. Intake throttle, exhaust gas recirculation (EGR) valve, intake manifold blow-off valve, compressor bypass valve, exhaust throttle, turbocharger geometry or turbocharger waste gate may be controlled to effectuate counter flow management separately or in combination. Excessive transient conditions may also be prevented or managed by sequential valve motion in which brake motion activation occurs first and then exhaust valve main event deactivation occurs second. Delay between brake activation and main event deactivation may be facilitated using mechanical and/or hydraulic implements as well as electronically.

Systems and methods for managing excessive intake flow path pressure and counter flow are implemented to support enhanced engine braking applications, such as 2-stroke or 1.5-stroke engine braking implementations where the intake flow path may be exposed to excessive transient pressures in the combustion chamber during activation or deactivation of an engine brake. Intake throttle, exhaust gas recirculation (EGR) valve, intake manifold blow-off valve, compressor bypass valve, exhaust throttle, turbocharger geometry or turbocharger waste gate may be controlled to effectuate counter flow management separately or in combination. Excessive transient conditions may also be prevented or managed by sequential valve motion in which brake motion activation occurs first and then exhaust valve main event deactivation occurs second. Delay between brake activation and main event deactivation may be facilitated using mechanical and/or hydraulic implements as well as electronically.

A hydraulic lash assembly (HLA) for use in a valvetrain. The HLA preferably includes a first arm configured to transition a valve between a closed orientation and an open orientation. The first arm can include an engagement surface to receive a driving force from a timing member and to cause the valve to transition to the open orientation for a predetermined period. The HLA further preferably includes a second arm to receive a holding force from an actuator and a pivot section to couple to the first arm and displace the first arm based on the holding force from the actuator. Preferably, the first arm and the second arm form a lever arrangement whereby the pivot section of the second arm underlies and supports the first arm and allows for rotational movement of the first arm that is independent from the second arm.

A hydraulic lash assembly (HLA) for use in a valvetrain. The HLA preferably includes a first arm configured to transition a valve between a closed orientation and an open orientation. The first arm can include an engagement surface to receive a driving force from a timing member and to cause the valve to transition to the open orientation for a predetermined period. The HLA further preferably includes a second arm to receive a holding force from an actuator and a pivot section to couple to the first arm and displace the first arm based on the holding force from the actuator. Preferably, the first arm and the second arm form a lever arrangement whereby the pivot section of the second arm underlies and supports the first arm and allows for rotational movement of the first arm that is independent from the second arm.

An internal combustion engine system includes an engine with a plurality of pistons housed in respective ones of a plurality of cylinders, an air intake system to provide air to the plurality of cylinders through respective ones of a plurality of intake valves, an exhaust system to release exhaust gas from the plurality of cylinders through respective one of a plurality of exhaust valves. A valve train is provided for cylinder deactivation of a first part of the plurality of cylinders and compression release braking on a second part of the plurality of cylinders.