A carburetor for a two-stroke internal combustion engine whereby airtightness is maintained and intake of uncombusted fuel into an air path is prevented. The carburetor includes a circular cylindrical valve hole and a rotary valve fitted into the valve hole such that it can rotate and is disposed perpendicularly across a fuel intake path and an air intake path which are formed substantially parallel with respect to each other, and a fuel supply-side bore which controls the flow rate along the fuel intake path and the air supply-side bore which controls the air capacity along the air path pass through part of the cylindrical portion perpendicularly to the axial direction of the rotary valve, and annular recesses formed in part of a circumferential wall of an outer circumference of the rotary valve so as not to correspond to at least the fuel supply-side bore and the air supply-side bore.

A carburetor for a two-stroke internal combustion engine whereby airtightness is maintained and intake of uncombusted fuel into an air path is prevented. The carburetor includes a circular cylindrical valve hole and a rotary valve fitted into the valve hole such that it can rotate and is disposed perpendicularly across a fuel intake path and an air intake path which are formed substantially parallel with respect to each other, and a fuel supply-side bore which controls the flow rate along the fuel intake path and the air supply-side bore which controls the air capacity along the air path pass through part of the cylindrical portion perpendicularly to the axial direction of the rotary valve, and annular recesses formed in part of a circumferential wall of an outer circumference of the rotary valve so as not to correspond to at least the fuel supply-side bore and the air supply-side bore.

Methods and systems are provided for a boosted internal combustion engine. In one example, a system may include an intake system for supplying charge air, a compressor arranged in the intake system, a first shut-off element arranged in the intake system upstream of an impeller of the compressor, a bypass line that branches off from the intake system upstream of the first shut-off element and that rejoins the intake system upstream of the impeller, a second shut-off element arranged in the bypass line, a compressed air line that opens into the bypass line downstream of the second shut-off element, and a third shut-off element arranged in the compressed air line. A map width of the compressor may be increased by providing airflow to the impeller via the bypass line during low mass flow conditions, and impeller acceleration may be expedited by providing compressed air via the compressed air line.

The present invention provides, in an internal combustion engine of the type including: a combustion cylinder having a combustion chamber; an intake port in fluid communication with the combustion chamber; an intake valve for opening and closing the intake port; an exhaust port in fluid communication with the combustion chamber; and an exhaust valve for opening and closing the exhaust portion; the improvement comprising: (a) at least one intake injector disposed within the intake port for injecting a fluid into the combustion chamber; (b) at least one exhaust injector disposed within the exhaust port for injecting a fluid toward the exhaust valve; and (c) means for controlling the at least one intake injector and the at least one exhaust injector.

A system for optimizing performance of an engine, including an intake manifold with an upper mount, plenum floor defining a plenum opening, lower mount defining intake openings, and intake runners communicating between the plenum and intake openings. The upper mount may be coupled to an air inlet device and the lower mount may be coupled to a cylinder head. A mountable device has an upper portion and lower portion and is configured to be inserted through the upper mount of the intake manifold to be coupled to the plenum floor so the mountable device covers the plenum opening and at least the upper portion of the mountable device remains between the upper mount and the plenum floor. A fixation system is configured align the mountable device to the intake manifold and to prevent the mountable device from decoupling from the plenum floor during engine operation. The mountable device is interchangeable without removing the intake manifold from the cylinder head.

A valve arrangement for supplying air to an internal combustion engine includes a first valve and a second valve arranged within the first valve. A valve guide for use in a valve arrangement is also provided.

A carburetor for a two-stroke internal combustion engine whereby airtightness is maintained and intake of uncombusted fuel into an air path is prevented. The carburetor includes a circular cylindrical valve hole and a rotary valve fitted into the valve hole such that it can rotate and is disposed perpendicularly across a fuel intake path and an air intake path which are formed substantially parallel with respect to each other, and a fuel supply-side bore which controls the flow rate along the fuel intake path and the air supply-side bore which controls the air capacity along the air path pass through part of the cylindrical portion perpendicularly to the axial direction of the rotary valve, and annular recesses formed in part of a circumferential wall of an outer circumference of the rotary valve so as not to correspond to at least the fuel supply-side bore and the air supply-side bore.

A carburetor for a two-stroke internal combustion engine whereby airtightness is maintained and intake of uncombusted fuel into an air path is prevented. The carburetor includes a circular cylindrical valve hole and a rotary valve fitted into the valve hole such that it can rotate and is disposed perpendicularly across a fuel intake path and an air intake path which are formed substantially parallel with respect to each other, and a fuel supply-side bore which controls the flow rate along the fuel intake path and the air supply-side bore which controls the air capacity along the air path pass through part of the cylindrical portion perpendicularly to the axial direction of the rotary valve, and annular recesses formed in part of a circumferential wall of an outer circumference of the rotary valve so as not to correspond to at least the fuel supply-side bore and the air supply-side bore.

A method of reducing NO.sub.x in the exhaust of a diesel engine having at least one combustion chamber by introducing NH.sub.3 into the diesel engine prior to a combustion event, at least some of the NH.sub.3 injected reducing the amount of NO.sub.x in the exhaust of the diesel engine, whereby the exhaust will contain an amount of NO.sub.x that is less than if no injection of NH.sub.3 was used, and will also contain an amount of NH.sub.3 that is less than the amount injected into the diesel engine, the rest of the NH.sub.3 being consumed during the combustion event and the reduction of NH.sub.3.

Fluid control valve including a valve body and an energizing member. The body is engaged with one end of a rotating shaft and moves along an axial direction of the shaft based on shaft rotation. The body opens and closes a first opening by the outer periphery, and one end comes into contact with and separates from a second opening. The member energizes the body on another end side of the shaft. A portion abutting on the second opening and a flow passage in which a fluid flows are at the one end of the body in the case where the first opening is fully closed. Since a valve-closed position of the body can be secured, and fluid flows in the flow passage, when a low flow rate is controlled, a stable flow rate is secured without closing the second opening which is a suction port in a valve-closed position.