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.

A rocker arm assembly operable in a first mode and a second mode, the rocker arm assembly selectively opening first and second engine valves based on rotation of a cam shaft having a first cam lobe and a second cam lobe, includes: a rocker shaft; a first rocker arm assembly having a first rocker arm that receives the rocker shaft and rotates around the rocker shaft in the first mode based on engagement with the first cam lobe; a second rocker arm assembly having a second rocker arm that receives the rocker shaft and rotates around the rocker shaft and selectively act on one of the first and second engine valves in the second mode based on selective engagement with the second cam lobe; and a biasing assembly that cooperates with the second rocker arm to bias the second rocker arm to a neutral position.

A rocker arm assembly operable in a first mode and a second mode, the rocker arm assembly selectively opening first and second engine valves based on rotation of a cam shaft having a first cam lobe and a second cam lobe, includes: a rocker shaft; a first rocker arm assembly having a first rocker arm that receives the rocker shaft and rotates around the rocker shaft in the first mode based on engagement with the first cam lobe; a second rocker arm assembly having a second rocker arm that receives the rocker shaft and rotates around the rocker shaft and selectively act on one of the first and second engine valves in the second mode based on selective engagement with the second cam lobe; and a biasing assembly that cooperates with the second rocker arm to bias the second rocker arm to a neutral position.

A method of manufacturing a bearing pin with an external lubrication channel and the bearing pin formed thereby are disclosed. The method includes fixing a rotational orientation of the bearing pin along a pin axis, cutting an outer surface of the bearing pin in a first straight line across a first convex portion thereof to create a first open external groove of the lubrication channel; and cutting an outer surface of the bearing pin in a second straight line across a second convex portion thereof to create a second open external groove of the lubrication channel. The grooves have a concave sectional profile and circumferential open ends disposed intermediate and not intersecting the ends of the bearing pin.

A method of manufacturing a bearing pin with an external lubrication channel and the bearing pin formed thereby are disclosed. The method includes fixing a rotational orientation of the bearing pin along a pin axis, cutting an outer surface of the bearing pin in a first straight line across a first convex portion thereof to create a first open external groove of the lubrication channel; and cutting an outer surface of the bearing pin in a second straight line across a second convex portion thereof to create a second open external groove of the lubrication channel. The grooves have a concave sectional profile and circumferential open ends disposed intermediate and not intersecting the ends of the bearing pin.

A rocker arm assembly can comprise a main rocker arm and a latch assembly. A latching arm can control the latch assembly and thereby control the extent to which a secondary rocker arm acts on the main rocker arm. The main rocker arm can comprise a main body configured to rotate around a rocker shaft, a valve end extending from the main body, a reaction end extending from the main body, and a latch bore. A bias pin can extend from the main body. The latch assembly can be configured to selectively rotate in the latch bore. The latch assembly can comprise a first latch end comprising a switch plate configured to receive actuation force on a first side and to receive bias force from the bias pin on a second side. A second latch end can comprise a first latch seat and a second latch seat.

A castellation assembly comprises a lost motion spring assembly, an upper castellation piece, and a lower castellation piece. A spring hat comprises a crown, a pin hole through the crown, and a brim. A lost motion spring is seated against the spring hat.

Upper castellation piece comprises a tubular body, an upper inner rim adjoining the brim, and upper castellation teeth. Lower castellation piece comprises a spring post extending up from a castellation body, the spring post passing through the lost motion spring, and through the pin hole. Lower castellation teeth extend from the castellation body. The lost motion spring is biased against the castellation body to lift the upper inner rim by the brim. A lash screw can house the spring post so that the spring post terminates inside the lash screw. A rocker arm is an example of a castellation assembly installation.

An internal combustion engine includes an engine block, a piston, a cylinder head, and a valve train. The engine block includes a cylinder block including a cylinder bore and a crankcase defining a crankcase chamber with a crankshaft positioned within the crankcase chamber. The piston is coupled to the crankshaft and configured to reciprocate within the cylinder bore. The cylinder head is coupled to the cylinder block. The valve train includes a camshaft, a first and second pushrod, a first and second rocker arm, an exhaust valve housed, and an intake valve. The first rocker arm, the second rocker arm, the exhaust valve, and the intake valve each include at least a layer of a low friction material. The first and second pushrod each pass through a pushrod seal to prevent fluid from reaching the rocker chamber to fluidly isolate the rocker chamber from the crankcase chamber.

Disclosured herein are apparatus and methods relating to combustion engines. In an example, a combustion engine includes a head and a rocker assembly. The rocker assembly including: a rocker shaft including therein a pressure reservoir, a pedestal support adapted to be fastened to the head and sized and structured to support the rocker shaft, a rocker lever pivotally supported by the rocker shaft, and a hydraulic engine brake mechanism within the rocker lever including a hydraulic control valve configured to selectively actuate an exhaust valve of the combustion engine.

An actuator assembly for a variable turbine geometry (VTG) turbocharger is disclosed. The actuator assembly may include an actuator and an actuator linkage having a first end coupled to the actuator and a second end defining a linkage joint. The actuator assembly may further include a VTG lever having a ball stud bore extending through the VTG lever. Additionally, the actuator assembly may include a ball stud including a first end partially disposed within the linkage joint and a second threaded end extending axially through the ball stud bore. Furthermore, a nut may be aligned with the ball stud bore and movably attached to the VTG lever prior to extending the ball stud through the ball stud bore, wherein the ball stud engages with the nut and fastens the ball stud to the VTG lever to operatively couple the VTG lever to the actuator linkage.