An overhead cam engine system comprises a rotating overhead exhaust cam rail comprising a plurality of exhaust lobes. A first switching roller finger follower actuates a first exhaust valve, and is configured to switch between a first lift profile and a second lift profile. A second switching roller finger follower is coupled to actuate a second exhaust valve, and is configured to switch between a third lift profile and a fourth lift profile. The third and fourth lift profile are different than the first and second lift profile. An actuation assembly is connected to switch the first switching roller finger follower and the second switching roller finger follower to select between at least three exhaust lift modes to open and close the first exhaust valve and the second exhaust valve using combinations of the first, second, third and fourth lift profiles.

A phase-shifting device, a so-called cam phaser, is arranged between a crankshaft and at least one camshaft to change the at least one camshaft's rotational position in relation to the crankshaft and thus push forward or defer at least one inlet valve's and/or at least one exhaust valve's opening and closing time. The phase-shifting device is connected to an accumulator that can be charged by an oil pump. The oil pressure may be increased with the help of a pressure medium controlled cylinder before or during a phase-shifting process.

A method for controlling intake and exhaust valves of an engine includes: controlling, by an intake continuous variable valve timing (CVVT) device and an exhaust CVVT device, opening and closing timings of the intake valve and exhaust valves; determining, by a controller, a target opening duration of the intake and exhaust valves based on an engine load and an engine speed; modifying, by an intake continuous variable valve duration (CVVD) device and by an exhaust two-stage variable valve duration device, current opening and closing timings of the intake valve and exhaust valve based on the target opening durations. In particular, the exhaust two-stage VVD device switches a current opening duration of the exhaust valve to a first exhaust opening duration or a second exhaust opening duration which is shorter than the first opening duration based on the target opening duration of the exhaust valve.

A sleeve includes: a supply port communicated with a hydraulic oil supply source; a primary control port communicated with a retard chamber, a secondary control port communicated with an advance chamber; and a drain port communicated with an outside of a valve timing adjustment device. A spool includes: a pressure accumulation space formed at an inside of the spool; a supply passage configured to connect between the pressure accumulation space and the supply port; a primary control passage configured to connect between the pressure accumulation space and the primary control port; a secondary control passage configured to connect between the pressure accumulation space and the secondary control port; and a recycle passage configured to connect between the primary control port or the secondary control port and the pressure accumulation space. The recycle passage and the drain port are connected with each other at the inside of the sleeve.

Systems, devices, and methods are disclosed for supporting one or more camshafts by the engine block in overhead arrangement relative to the cylinder heads and valve train.

A control device for an engine includes a valve-stopping mechanism 14b which holds intake and exhaust valves 41, 51 of the first and the fourth cylinders (idle cylinders) of four cylinders in closed states, a throttle valve control unit 115, an ignition period control unit 113, and an ECU 110 which controls the valve-stopping mechanism 14b, the throttle valve control unit 115, and the ignition period control unit 113. The ECU 110 sets a retard amount of the ignition period of the idle cylinder behind the basic ignition period at least in starting the all-cylinder operation in accordance with an amount of burned gas existing in the idle cylinder in switching to the all-cylinder operation from the reduced-cylinder operation.

A method for adaptation of a detected camshaft position of a camshaft in an internal combustion engine with: Detection of an ACTUAL gas signal in a gas space that is associated with the camshaft and is associated with a detected camshaft position; Processing of the gas signal to produce an ACTUAL gas criterion; Modeling of multiple simulated gas criteria, each of which is associated with a target camshaft position; Determination of a simulated gas criterion with the least deviation from the ACTUAL gas criterion; Determination of an ACTUAL camshaft position that corresponds to the simulated gas criterion with the least deviation from the ACTUAL gas criterion; Determination of a camshaft position correction value from the difference between the ACTUAL camshaft position determined and the detected camshaft position; Determination of corrected camshaft positions by correcting the detected camshaft positions with the camshaft position correction value.

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.

An internal combustion engine includes a cylinder head, a support structure, a cam pulley, and a seal member. The support structure is provided above the cylinder head and supports the camshaft. The cam pulley is provided at an end of the camshaft. A timing belt is wound around the cam pulley. A seal member is provided to cover a gap provided between the cylinder head and the support structure at a facing surface facing the cam pulley. The seal member provides sealing between the cylinder head and the support structure in an axial direction of the camshaft.

A hydraulic lash adjuster for use in diesel engines including a cylinder head having a first valve, a second valve, and a valve bridge extending between and in contact with both the first valve and the second valve. Where the diesel engine includes a first rocker arm, and where at least one of the first valve and the second valve undergo an oil can valve deflection rate. The hydraulic lash is configured to selectively transmit force between the first rocker arm and the valve bridge, and where the hydraulic lash adjuster is normally in the open configuration, and where the hydraulic lash adjuster changes from the open configuration to a closed configuration at a critical velocity that is greater than the oil can valve deflection rate.