A system for selectively activating and deactivating cylinders includes a first cylinder positioned in a cylinder block. A first intake or exhaust valve is coupled to the first cylinder and is actuated by a first coupling mechanism. A first oil control solenoid is coupled to the first coupling mechanism, the first oil control solenoid deactivates the first coupling mechanism to maintain the first intake or exhaust valve in a closed position. A second cylinder is positioned in the cylinder block, and a second intake or exhaust valve is coupled to the second cylinder. The second intake or exhaust valve is actuated by a second coupling mechanism. A second oil control solenoid is coupled to the second coupling mechanism, the second oil control solenoid deactivates the second coupling mechanism to maintain the second intake or exhaust valve in a closed position. The first oil control solenoid and the second oil control solenoid have different operating parameters.

A camshaft assembly for a vehicle valvetrain having first and second engine valves includes a camshaft, and a first camshaft cartridge axially displaceable along the camshaft and including a plurality of first cam lobes configured to selectively impart movement to the first engine valve. A second camshaft cartridge is axially displaceable along the camshaft and includes a plurality of second cam lobes configured to selectively impart movement to the second engine valve. An actuator is configured to axially displace the first camshaft cartridge along the camshaft. A coupling is between the first camshaft cartridge and the second camshaft cartridge. Axial displacement of the first camshaft cartridge selectively imparts movement to the second camshaft cartridge for axial displacement of the second camshaft cartridge.

A method for controlling a valve arrangement for an internal combustion engine, the valve arrangement including a piston arrangement comprising a piston having a piston end portion facing an inlet valve of the valve arrangement. The method includes receiving a signal indicative of a temperature level of an exhaust gas after treatment system and when the signal indicates a temperature level below a predetermined threshold level: advancing an exhaust event of the internal combustion engine; and controlling the piston arrangement for reducing the distance between the piston end portion and the inlet valve before the internal combustion engine assumes an air intake event.

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.

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.

Methods and systems are provided for actuating an advanced cam profile switch (CPS) assembly. In one example, a system may include a first cylinder and a second cylinder of the CPS assembly that may be independently coupleable to a valve stem via two separate locking mechanisms. A first cam may be selectively engage with the first cylinder and the valve stem and a second cam may be selectively engaged with the second cylinder and the valve stem.

Systems and methods to extend a life of a component of a cylinder deactivation system are provided. A method includes generating, by a controller, an initial life factor for the component; initiating, by the controller, a CDA mode for an engine; determining, by the controller, an actual life factor for the component, the actual life factor determined by comparing a number of switching events of a cylinder in the CDA mode to a number of cycles of the cylinder in the CDA mode; comparing, by the controller, the actual life factor to the initial life factor; and modifying, by the controller based on the comparison, operation of the engine in the CDA mode to adjust the actual life factor.

A fully variable electro-hydraulic valve system, comprising a sliding sleeve (A103, B103), a spiral shaft (A102, B102), a piston (A105, B105), and a reset spring (A104, B104); the sliding sleeve (A103, B103) is fixed relative to an engine; the piston (A105, B105) abuts against a valve assembly (106); the spiral shaft (A102, B102) is axially controlled by a cam surface of a camshaft (101); and the spiral shaft (A102, B102) is provided with a spiral groove (A102D, B102D) and a blockage part (A102G, B102G). When the spiral groove (A102D, B102D) communicates with a limiting oil hole (A118, B118), a sliding sleeve cavity (Q) communicates with a low-pressure oil path of the engine for pressure relief; a spiral shaft axial projection portion (A102C, B102C) is provided at a first end of the spiral shaft (A102, B102); the spiral shaft axial projection portion (A102C, B102C) is provided with a spiral shaft abutting plane (A102B, B102B); a piston axial projection portion (A105A, B105A) is provided at the end of the piston (A105, B105) opposite to the spiral shaft (A102, B102); and the head portion of the piston axial projection portion (A105A, B105A) is provided with a piston abutting plane (A105B, B105B). The present invention solves the problem in which the normal operation of the system is affected due to machine oil loss in a sliding sleeve cavity, and enables the crank angle corresponding to a valve opening moment to remain unchanged, and is particularly suitable for applying to the control of the intake valve variable stroke of an engine having a scavenging process.

A control method can be used for securing continuously variable valve duration (CVVD) startability when a CVVD error is recognized by a CVVD controller during an operation of a CVVD system. The control method includes performing engine startability securing control for solving the CVVD error by applying a starting air volume to starting of an engine through at least one of a valve position fixing value, a valve position threshold, or an immediately previous valve position value.

A lifter assembly can comprise an outer body comprising an oil port and opposed latch ports. An inner body can comprise a roller assembly or tappet configured to lift and lower to follow a cam. The inner body comprises a pin passage comprising an inner diameter. A pin assembly is mounted in the pin passage. The pin assembly comprises a bushing abutting the inner diameter. The bushing comprises a pin port. A pin comprises a rim and a narrow end configured for sliding in the pin port.