A variable camshaft timing system including a first camshaft phaser having an input that is configured to receive rotational force from a crankshaft and an output that is configured to link with a first camshaft of a concentric camshaft assembly to change the angular position of the first camshaft relative to a crankshaft; and a second camshaft phaser having an output that is configured to link with a second camshaft of the concentric camshaft assembly to change the angular position of the second camshaft relative to the crankshaft, wherein the first camshaft is concentrically positioned to the first camshaft and the first camshaft phaser is mechanically linked to the second camshaft phaser to communicate rotational force from the crankshaft to the second camshaft phaser through the first camshaft phaser and the mechanical link.

A marine engine has an intake camshaft, an exhaust camshaft, and a crankshaft. Combustion in the marine engine causes rotation of the crankshaft which in turn causes rotation of the intake camshaft and exhaust camshaft. Rotation of the intake camshaft operates intake valves for controlling inflow of air to the marine engine. Rotation of the exhaust camshaft operates exhaust valves for controlling outflow of exhaust gas from the marine engine. A cam phaser is located at least partially inside at least one of the intake camshaft and the exhaust camshaft and is configured to vary a timing of operation of at least one of the intake valves and exhaust valves.

A variable camshaft timing (VCT) assembly for controlling the angular position of concentric camshafts includes an independent VCT device that is configured to couple with a first concentric camshaft and change an angular position of the first concentric camshaft relative to an angular position of a crankshaft; and one or more dependent VCT devices mechanically linking an output of the independent VCT device with a second concentric camshaft, wherein the dependent VCT device(s) change(s) an angular position of the second concentric camshaft relative to the angular position of the first concentric camshaft based on angular movement of the output of the independent VCT device.

Presented are variable compression ratio and independent compression and expansion engines, methods for making/operating such engines, and vehicles equipped with such engines. An engine assembly includes an engine block with a cylinder bore defining a combustion chamber, and a piston movable within the cylinder bore. A valve assembly, which is fluidly coupled to the combustion chamber, selectively introduces/evacuates fluid from the combustion chamber. A crankshaft is supported by the engine block and rotatable on a first axis. A multipoint linkage, which drivingly engages the piston to the crankshaft, rotates on a second axis offset from the first axis. A control shaft is supported by the engine block and rotates on a third axis offset from the first and second axes. The control shaft operable to selectively rotate the multipoint linkage on the second axis, and is operable to selectively unseat the valve assembly.

A variable camshaft timing system including a first camshaft phaser having an input that is configured to receive rotational force from a crankshaft and an output that is configured to link with a first camshaft of a concentric camshaft assembly to change the angular position of the first camshaft relative to a crankshaft; and a second camshaft phaser having an output that is configured to link with a second camshaft of the concentric camshaft assembly to change the angular position of the second camshaft relative to the crankshaft, wherein the first camshaft is concentrically positioned to the first camshaft and the first camshaft phaser is mechanically linked to the second camshaft phaser to communicate rotational force from the crankshaft to the second camshaft phaser through the first camshaft phaser and the mechanical link.

A variable camshaft timing system for an internal combustion engine with an idler shaft mounted camshaft phaser is provided. The camshaft phaser includes a driven wheel that is driven by the crankshaft, a driving wheel that drives the camshaft, and a hydraulically driven phasing assembly therebetween. A valve body is connected to the idler shaft for directing the flow of pressurized hydraulic medium to the camshaft phaser. The valve body includes a center part with an integral retainer for holding the camshaft phaser on the idler shaft, and a radial extension integrally connected to the center part that extends radially outwardly from an axis of the idler shaft a predefined distance. A control valve receiving part is integrally connected to radial extension and includes a control valve bore. A control valve is located in the control valve bore in the valve body. The control valve extends through the engine cover at a desired location for control valve maintenance.

A variable camshaft timing (VCT) assembly for controlling the angular position of concentric camshafts includes an independent VCT device that is configured to couple with a first concentric camshaft and change an angular position of the first concentric camshaft relative to an angular position of a crankshaft; and one or more dependent VCT devices mechanically linking an output of the independent VCT device with a second concentric camshaft, wherein the dependent VCT device(s) change(s) an angular position of the second concentric camshaft relative to the angular position of the first concentric camshaft based on angular movement of the output of the independent VCT device.

A spark-ignited gas engine system comprises a combustion chamber defined by a piston, a head with a spark plug mechanism, and a cylinder having an associated intake valve and an associated exhaust valve, into which a mixture of combustible gas and air is entered via an intake manifold of the engine to drive a crankshaft. The system further comprises at least one turbocharger to compress the mixture. The system further comprises at least one camshaft, driven by the crankshaft via a gear assembly connected to the crankshaft, that comprises at least one cam that actuates the intake valve and the exhaust valve, at least one camphaser, coupled to the crankshaft via the gear assembly, and a controller to adjust a cam angle operation of the intake valve and the exhaust valve by adjusting the camphaser to a desired phase position to meet a target rotational phase of the camshaft.

A collapsible valve bridge actuation system that is configured to alter the lift of poppet valves in a reciprocating piston machine cylinder. The system has a rocker arm configured to be actuated by a cam lobe, and a collapsible valve bridge device that is functionally attached to the rocker arm. The device has a deactivation assembly that contains lock pins within a housing and springs. Also, the device is configured to remain rigid, partially collapse, or fully collapse. The extent of collapse is a function of the strength of the springs.

A variable camshaft timing device adjusts phase between a camshaft and a crankshaft and includes a first ring gear configured to connect to the camshaft and rotate about a center axis, having a plurality of radially-inwardly facing gear teeth; a second ring gear axially spaced from the first ring gear, configured to receive rotational input from the crankshaft and rotate about the center axis, having a plurality of radially-inwardly facing gear teeth; a planetary gear assembly including one or more planet gears that are configured for rotation by an electric motor and engage the first ring gear and the second ring gear through the planet gear(s); and a cushioned stop configured to transmit energy between the planetary gear assembly and a planetary gear stop attached to a sprocket or a camshaft plate.