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 gas engine is disclosed. The gas engine may include a combustion cylinder. The combustion cylinder may include an intake with an intake valve. The combustion cylinder may include an exhaust with an exhaust valve. The gas engine may include a gas admission valve assembly coupled to the intake. The gas admission assembly may include a trimmable electro-hydraulically actuatable gas admission valve to control a gas flow into the intake.

A technique for testing a pushrod valvetrain in an engine includes replacing an original pushrod with an instrumented pushrod (IPD) which includes a sensor configured to measure strain and/or motion. The engine is then operated, and the output of the sensor is monitored for anomalies. Diagnosis and repair of identified defects may then follow.

A roller hydraulic valve lifter includes a body having a longitudinal central axis and an interior area defined by an inside surface which has a pair of flat surfaces opposite one another and connected by a pair of walls. A first bore, essentially perpendicular to the longitudinal axis, extends through the flat surfaces. A bearing is disposed partially in the interior area. The bearing includes an outer ring having substantially cylindrical exterior and interior bearing surfaces. A shaft extends through the first bore and the outer ring and between the pair of flat surfaces. A plurality of needle rollers is disposed between and rollingly engage the shaft and the cylindrical inner bearing surface. The shaft and the plurality of needle rollers are manufactured from an AISI 52100 alloy steel that is carbo-nitrided. The shaft and the plurality of needle rollers have a surface hardness of a minimum of HRc 65.

An internal combustion engine has a valvetrain that includes a rocker arm assembly on which is mounted an electronic device and at least a part of a generator. The generator converts some of the mechanical energy that is transmitted through the rocker arm assemblies into electricity. That electricity may be used to power an electric latch, a transmitter, or another type of rocker arm assembly-mounted electrical device. Various generator configurations are described. In some configurations, the generator is piezoelectric. In other configurations, the generator is electromagnetic. In some configurations, the generator is driven by force transmitted by the rocker arm assembly from a cam. In some configurations, the generator is driven by vibrations.

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.

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.

A hydraulic tappet configured for a valve train of an internal combustion engine is provided. The tappet includes an outer housing, a socket plunger, and a hydraulic lash adjuster assembly. The socket plunger and the hydraulic lash adjuster assembly are disposed within the outer housing. The hydraulic lash adjuster assembly includes an outer casing, a piston, and a check valve assembly. The outer casing is configured with a spherical first end. The hydraulic lash adjuster assembly can include a swivel pad that engages the spherical first end. The piston is at least partially received by an opening in the outer casing. The piston and socket plunger define a first fluid chamber, while the piston and outer casing define a second fluid chamber. The check valve assembly is arranged to fluidly connect the first fluid chamber to the second fluid chamber.

A valvetrain assembly configured to selectively perform a bleeder brake operation includes a rocker arm configured to rotate about a rocker shaft, a camshaft having a lobe configured to impart motion to the rocker arm through a pushrod, and a valve bridge assembly operably associated with the rocker arm and configured to be selectively engaged by the rocker arm to open at least one of a first and second engine valve. An engine brake capsule is operably associated with the valve bridge assembly and configured to operate in a drive mode where the engine brake capsule does not cause the valve bridge assembly to open the first or second engine valves, and a brake mode where the engine brake capsule engages the valve bridge assembly to partially open the first engine valve to perform the bleeder brake operation.

A method for controlling a transmission of a vehicle during cylinder deactivation can comprise receiving and processing a zero or negative torque requirement for the vehicle. Receiving and processing vehicle speed data can be included to determine a vehicle speed for the vehicle. A cylinder deactivation mode can be implemented for a valvetrain of a multi-cylinder engine of the vehicle, wherein the cylinder deactivation mode comprises deactivating one or more intake valve, one or more exhaust valve, and fuel injection for one or more cylinder of the multi-cylinder engine. Selecting one of an in-gear mode and a neutral mode for a transmission of the vehicle can be included while implementing the cylinder deactivation mode and while maintaining the determined vehicle speed.