A dual body rocker arm for a valve train assembly of an internal combustion engine includes: an outer body having a protrusion; an inner body connected to the outer body and arranged for pivotal movement relative to the outer body about an axis between a first position and a second position; and a torsional biasing element supported by the protrusion and arranged to bias the inner body relative to the outer body towards one of the first position and the second position. The protrusion is formed integrally with the outer body.

An internal combustion engine is configured to periodically open and close combustion chamber exhaust valves of the engine such that one exhaust valve is held open longer than another exhaust valve and/or one exhaust valve opens before another exhaust valve relative to top dead center. The resulting differential exhaust valve timing can at least partially compensate for different swallowing capacities of the scrolls of a twin-scroll turbine.

A method and apparatus for continually and rapidly adjusting the output torque of an engine according to a torque demand uses an active tappet to vary the instant air charge in a combustion chamber. The invention allows substantially efficient combustion throughout the engine operating map. Various methods of changing the charge of air are disclosed.

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.

An apparatus includes a valve and an actuator. The valve has a portion movably disposed within a valve pocket defined by a cylinder head of an engine. The valve is configured to move relative to the cylinder head a distance between a closed position and an opened position. The portion of the valve defines a flow opening that is in fluid communication with a cylinder of an engine when the valve is in the opened position. The actuator is configured to selectively vary the distance between the closed position and the opened position.

A tubular roller valve for an internal combustion engine, which includes a hollow tube having at least one hole, the at least one hole being configured to access an air inlet or an exhaust of a cylinder in an engine block, a tubular outer insulator outside of the hollow tube, the outer insulator being fixed to a cylinder head, and a tubular inner insulator inside of the hollow tube. An additional tube between the hollow tube and the outer insulator can serve to operate as a compression release brake.

To improve fuel efficiency, some gasoline engines are equipped with valve deactivators in some of the cylinders so that at low torque conditions only a subset of the total number of cylinders are active. In prior art engines, particularly when they have four valves per cylinder, space is tight. It is known to provide a cam carrier in the head between the cylinder head and the camshaft. The cylinder head bolts pass through the head under the cam carrier. According to the present disclosure, the cam carrier, and its associated disadvantages, is obviated by widening the bearings for the camshafts, using smaller diameter head bolts, and putting the orifices tor the head bolts directly through the bearings.

A variable valve control system may include a variable valve mechanism having latching pins for performing variable valve lift by a pressure difference of oil, an oil control circuit block having a low-pressure oil line and a high-pressure oil line to control ON/OFF of the latching pins, and a rotation shaft valve having oil passages for switching the low-pressure oil line and the high-pressure oil line.

A system for controlling a variable valve apparatus may include a plurality of oil control valves (OCVs) configured to respectively supply oil from an oil pump to a plurality of variable valve apparatuses or block the supply of the oil, and a single relief valve coupled to the plurality of oil control valves, wherein pressure in a plurality of control galleries for providing an oil supply path from the plurality of oil control valves to the plurality of variable valve apparatuses is maintained constant by only the single relief valve.

Methods and systems are provided for a cam carrier insert coupled to a cylinder head of an engine. In one example, a system may comprise: a cylinder head with a cam bearing tower; a cam carrier insert positioned in the cylinder head; and a camshaft, the camshaft directly supported by the cam bearing tower and directly supported by the cam carrier insert. By mounting a first portion of the cam shaft to the cam bearing tower and a second portion of the cam shaft on the cam carrier insert, the system may operate deactivatable and non-deactivatable intake or exhaust valves of one or more engine cylinders in the engine. In this way, packaging of engine components within the cylinder head may be improved while promoting better engine performance.