Some examples described herein may involve determining an advance timing window between the valve opening or closing and a designated time that the valve is scheduled to open or close; determining a closing velocity of the valve; monitoring an engine speed of the engine; determining valve lash information based on the advance timing window, the closing velocity, and the engine speed, wherein the valve lash information identifies a magnitude of the valve lash or whether the magnitude of the valve lash associated with the valve satisfies a threshold; and performing an action based on the valve lash information.

A sensor mounting structure for an engine is provided. The sensor mounting structure offers a greater flexibility in mounting a sensor which detects an operation of an actuation member disposed at an inner wall spaced apart from an outer wall of a cylinder head of a valve gear. A sensor mounting structure for an engine includes a valve gear provided at a cylinder head and a sensor detecting an operation of the valve gear. The sensor is mounted on a sensor mounting hole formed at a head inner wall of the cylinder head covered with a cylinder head cover.

A method for cleaning a continuously variable valve timing (CVVT) system for removing foreign materials includes: switching a target operating value of the CVVT system to a predetermined setting value within a set operating region and performing cleaning of the CVVT system; and determining whether a valve timing control learning request exists for the CVVT system, and, when the valve timing control learning request exists, aborting the cleaning.

A method of forming a target wheel for a camshaft phaser assembly is disclosed. The method includes providing a sheet metal body, and stamping the sheet metal body to form a sensor tab. The sensor tab includes a medial flange positioned between first and second axially extending edges. The sensor tab includes: at least one inner corner defined between the medial flange and at least one of the first axially extending edge or the second axially extending edge, and at least one outer corner defined between the medial flange and at least one of the first axially extending edge or the second axially extending edge. The method includes forming a groove in the at least one inner corner.

The number of advance chambers is larger than the number of retard chambers in an intake variable valve timing (VVT), whereas the number of retard chambers is larger than the number of advance chambers in an exhaust VVT. Accordingly, with limitation of an oil pressure that can be used by the VVTs, a pumping loss in a transition period in which a valve overlap amount is changed by advancing or retarding a valve timing can be reduced.

Systems, apparatuses and methods are disclosed that include an internal combustion engine including a plurality of cylinders operable by a valve actuation mechanism including a lifting mechanism having a compression brake valve profile configured to selectively lift the exhaust valves on a downstroke of the cylinders in response to a cranking condition of the internal combustion engine, wherein the compression braking valve profile is phased to the upstroke of the pistons.

A camshaft phaser arrangement configured for a concentric camshaft assembly having an inner camshaft and an outer camshaft is provided. The camshaft phaser arrangement can facilitate independent phasing of intake and exhaust valves. The camshaft phaser arrangement includes a first driven wheel and a second driven wheel, both configured to be driven by a driving wheel. A first camshaft phaser is connected to the first driven wheel and configured to be connected to either the inner or outer camshaft. A second camshaft phaser is connected to the second driven wheel and configured to be connected to either the inner or outer camshaft which is not connected to the first driven wheel. A motion transfer assembly can connect the second camshaft phaser to the concentric camshaft assembly. One or both of the camshaft phasers can be an electric camshaft phaser or a hydraulic camshaft phaser.

A method for controlling intake and exhaust valves of an engine includes: Controlling opening and closing timings of the intake and exhaust valves by an intake continuous variable valve timing (CVVT) device and an exhaust CVVT devices; determining, by a controller, target intake and exhaust opening durations of the intake and exhaust valves, and target opening and closing timings of the valves based on an engine load and an engine speed; modifying current intake and exhaust opening durations based on the target opening durations via an intake continuous variable valve duration (CVVD) device and an exhaust CVVD device; adjusting opening or closing timings of the valves to the target opening or closing timings of the valves while maintaining the modified opening durations of the valves.

Disclosed is a camshaft toothed wheel, forming a target for a camshaft position sensor, the toothed wheel including a circular body including two opposite main faces, and at least six teeth distributed over the circumference of the circular body, each tooth including two edges, one corresponding to a rising edge and the other to a falling edge, as a function of a direction of rotation of the wheel, the toothed wheel having asymmetry of revolution. The six teeth are shaped so that the toothed wheel includes, considering the same main face and the same direction of rotation of the wheel: four edges of the same first rising or falling type spaced 90? apart, respectively; and six edges of the same second falling or rising type, respectively, spaced 60? apart, respectively.

Systems and methods for determining operation of a cylinder deactivating/reactivating device are disclosed. In one example, a direction of engine rotation is selected to maximize air flow through the engine while the engine is rotated without combusting air and fuel. Operation of one or more cylinder valve deactivating mechanisms is assessed while the engine is rotated without combusting air and fuel.