A method for controlling vehicle speed comprises selecting an engine speed profile for a vehicle. Road grade data is received and processed to determine a road grade for the vehicle. Vehicle speed data is received and processed to determine a vehicle speed for the vehicle. A cylinder deactivation mode for a valvetrain of a multi-cylinder engine of the vehicle is selected. The cylinder deactivation mode comprises deactivating one or more intake valve, exhaust valve, and fuel injection for one or more cylinder of the multi-cylinder engine. The selected cylinder deactivation mode provides a controlled deviation from the selected engine speed profile at the road grade and vehicle speed.

A latch assembly comprises a latch pin configured to reciprocate in a latch bore. The latch pin comprises a main body comprising a first plug end, a second plug end, and a clearance between the first plug end and the second plug end. The latch pin is configured to selectively move in the latch bore. A rocker arm assembly can comprise the latch assembly. An outer arm can be configured to rotate about a rocker shaft and comprise the latch bore. An inner arm can at least be partially disposed within the outer arm and configured to rotate. When the latch pin is in the activated position, the inner arm is configured to transfer force to the outer arm via the latch pin. When the latch pin is in the deactivated position, the inner arm is configured to move in the clearance and in the lost motion gap.

A rocker arm assembly can include an outer arm having an outer rocker shaft bore configured to receive a rocker shaft and an inner arm having an inner rocker shaft bore configured to receive the rocker shaft. The inner arm can be configured to selectively rotate. A latch pin can be movably seated in the outer arm and configured to move between a latched position and an unlatched position. The rocker arm assembly can further include a lost motion spring. The lost motion spring can include a first end connected to a connecting portion of the inner arm above the inner rocker shaft bore and a second end connected to the outer arm. The inner arm can include an inner arm stop member configured contact with a corresponding outer arm stop member of the outer arm.

A compression-release engine brake system operating an exhaust valve of an engine during a compression-release engine braking operation. The compression-release brake system comprises an exhaust rocker arm and a brake reset device disposed in a reset bore formed in the exhaust rocker arm. The brake reset device comprises a reset check valve, a slider-piston slidably disposed in the reset bore and an external slider bias spring biasing the piston foot away from the brake reset device. The external slider bias spring is disposed outside the reset bore and around the piston-slider. The brake reset device permits pressurized hydraulic fluid to flow from a supply conduit to a reset conduit to supply a brake actuation piston when the reset check valve is open. The actuation piston extends and engages the exhaust valve toward the end of a compression stroke of the internal combustion engine, and the brake reset device resets.

A switching roller finger follower (SRFF) assembly for valve actuation includes an outer arm and an inner arm pivotally coupled to the outer arm via a pivot axle and at least partially disposed within the outer arm. The inner arm is unitarily formed and has a first inner side arm and a second inner side arm having respective laterally spaced apart longitudinal bends that each define pin apertures. A spring engagement pin extends through the pin apertures, a pair of lost motion springs are supported by the pivot axle, an inner roller is rotatably coupled to the inner arm, and a pair of outer rollers are disposed on respective axles supported by the outer arm.

A valve actuation device for actuating a first and second gas exchange valve of an internal combustion engine. A tilting lever is pivotable between a first starting position and a first actuation position and a valve bridge is movable between a second starting position and a second actuation position. A coupling device is switchable between a locking state, in which the valve bridge is movable out of the second starting position into the second actuation position via the coupling device by the tilting lever, and an unlocking state, in which, despite a movement of the tilting lever out of the first starting position into the first actuation position, there is no movement of the valve bridge out of the second starting position into the second actuation position. The coupling device is held on the tilting lever such that the coupling device is pivotable with the tilting lever.

An engine brake rocker arm assembly is operable in an engine drive mode and an engine braking mode and selectively opens first and second exhaust valves. The engine brake rocker arm assembly includes an exhaust rocker arm configured to rotate about a rocker shaft, an engine brake capsule assembly movable between (i) a locked position configured to perform an engine braking operation, and (ii) an unlocked position that does not perform the engine braking operation, and a hydraulically controlled actuator assembly configured to selectively move the engine brake capsule assembly between the first and second positions.

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.

A rocker arm assembly operable in an engine drive mode and at least one of a late intake valve closing (LIVC) mode and an internal exhaust gas recirculation (iEGR) mode, the rocker arm assembly selectively opening first and second engine valves. The rocker arm assembly includes a rocker arm configured to rotate about a rocker shaft, and a reverse reset capsule assembly movable between (i) a locked position configured to perform one of an LIVC operation and an iEGR operation, and (ii) an unlocked position that does not perform the LIVC operation or the iEGR operation. An actuator assembly is configured to selectively move the reverse reset capsule assembly between the locked and unlocked positions.

A latch assembly comprises a latch pin and a cage. The latch pin comprises a latch nose and a pin body. The pin body comprises an outer surface and an inner compartment. The inner compartment comprises a first inner wall segmented by a first slot and a second inner wall segmented by a second slot. The first slot and the second slot vent out of the inner compartment. The cage comprises a stepped base and a shaft extending from the stepped base into the inner compartment. The shaft comprises a first exterior flat adjoining the first inner wall and a second exterior flat adjoining the second inner wall. A spring can be biased against the latch pin and the cage. The latch assembly can be used in a latching device of a valvetrain such as a switching roller finger follower or other rocker arm.