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.

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.

A control value calculation part includes an in-cylinder state estimation part that estimates a state to which the cylinder belongs between a plurality of PM-PN generation states. The plurality of PM-PN generation states are states in which a particulate matter is easily generated as compared with the other state, and are different from each other in a cause to generate the particulate matter. Further, in a case where it is determined that an operation state of an engine is a PM-PN exhaust state, the control value calculation part calculates a control value of an actuator in such a way to eliminate the PM-PN generation state according to the PM-PN generation state to which the state in the cylinder belongs.

A variable valve mechanism includes a variable arm including a first arm and a second arm. The second arm is pivotally supported so as to be swingable by a support shaft. A position of the support shaft is a position where, during a base circle phase, in side view, a second segment connecting an axis of a roller to an axis of the support shaft is longer than a first segment connecting the axis of the roller to an axis of a camshaft, and an angle of the second segment formed with respect to a third segment connecting the axis of the roller to a swing axis of a roller arm is 60° to 120° toward the camshaft. The second arm extends from the support shaft such that a distal end portion of the second arm protrudes in between a cam and the roller.

A switchable rocker arm for valve deactivation is provided for a valve train of an internal combustion engine. The switchable rocker arm includes a valve side lever assembly, a cam side lever assembly, and a hydraulically actuated coupling assembly. The valve side lever assembly includes a first housing with a first rocker shaft bore. The cam side lever assembly includes a second housing with a first arm with a second rocker shaft bore and a second arm with a third rocker shaft bore. The first and second arms extend along opposed longitudinal sides of the cam side lever assembly such that the first, second and third rocker shaft bores are axially aligned. The coupling assembly is arranged at an end furthest away from a pivot axis for minimal loading and provides locking and unlocking of the switchable rocker arm to achieve full valve lift and no valve lift modes, respectively.

An internal combustion engine includes an intake variable lift amount mechanism that changes a maximum lift amount and valve-open period of an intake valve, and an exhaust variable lift amount mechanism that changes a maximum lift amount and valve-open period of an exhaust valve. A control unit executes a process to increase the valve-open period of the intake valve and reduce the valve-open period of the exhaust valve, when idling with a temperature of the internal combustion engine that is equal to or higher than a reference value.

A valve train system for an internal combustion engine includes an exhaust valve moveable between an exhaust closed position and an exhaust open position. A camshaft includes a main exhaust lobe for moving the exhaust valve between the exhaust closed position and the exhaust open position for expelling exhaust constituents from the combustion chamber and an exhaust rebreath lobe for moving the exhaust valve between the exhaust closed position and the exhaust open position for allowing exhaust constituents into the combustion chamber. A two-step device is provided for transmitting motion from the camshaft to the exhaust valve and is switchable between a motion transmitting position and a motion preventing position such that the motion transmitting position allows motion to be transmitted from the exhaust rebreath lobe to the exhaust valve and the motion preventing position prevents motion from being transmitted from the exhaust rebreath lobe to the exhaust valve.

A control method for a continuously variable valve lift mechanism includes: controlling a continuously variable valve lift mechanism to enter a limp mode when the continuously variable valve lift mechanism fails and disables an automatic valve lift changing function; driving and forcing the continuously variable valve lift mechanism to move to a maximum lift position; and triggering a self locking function to self lock the continuously variable valve lift mechanism at the maximum lift position when the continuously variable valve lift mechanism reaches the maximum lift position. A control system for a continuously variable valve lift mechanism, and a vehicle are also provided.

A method for operating a reciprocating internal combustion engine in an engine braking mode includes, in a working cycle of the engine braking mode, a first outlet valve of a first cylinder is closed for a first time, then opened for a first time, and subsequently closed for a second time, and then opened for a second time, in order to thereby discharge gas that has been compressed in the first cylinder from the first cylinder by a cylinder piston. The outlet valve is held open after the first opening and prior to the second closing long enough for the cylinder to be filled with gas that flows out of a second cylinder via at least one outlet channel, where when the engine braking mode is activated, at least one camshaft for activating at least one gas exchange valve of the reciprocating internal combustion engine is adjusted.

An internal combustion engine is provided, which includes a variable phase mechanism configured to change rotational phases of intake and exhaust camshafts so that a valve overlap is made. An intake cam lobe is formed such that an open period of the intake valve is 210° or larger and 330° or smaller of a crank angle. The exhaust cam lobe is formed such that, during the overlap period with the rotational phase of the intake camshaft advanced to the maximum and the rotational phase of the exhaust camshaft retarded to the maximum, an effective valve lift amount (Lift(CA)) of the exhaust valve which is a function of a crank angle from the open timing (CA.sub.IVO) of the intake valve to a middle timing (CA.sub.center) of the overlap period, an inner circumferential length (L_ex) of a valve seat, and a swept volume (V) per cylinder satisfy the following formula: $0.015\le \frac{L\_\mathrm{ex}}{V}\times {\int }_{C{A}_{\mathrm{IVO}}}^{C{A}_{center}}\mathrm{Lift}\left(\mathrm{CA}\right)dCA.$