An intake manifold is for a marine engine having a throttle for controlling flow of intake air to the marine engine. The intake manifold has a plenum for receiving the intake air from the throttle, a plurality of intake runners which extends from upstream ends for receiving the intake air from the plenum to downstream ends for discharging the intake air to the marine engine, and a quarter wave resonator extending from an open end coupled to the plenum to a closed end, the quarter wave resonator having a tuned elongated cavity configured to attenuate sound emanating from the marine engine via the plurality of intake runners.

An intake manifold is for a marine engine having a throttle for controlling flow of intake air to the marine engine. The intake manifold has a plenum for receiving the intake air from the throttle, a plurality of intake runners which extends from upstream ends for receiving the intake air from the plenum to downstream ends for discharging the intake air to the marine engine, and a quarter wave resonator extending from an open end coupled to the plenum to a closed end, the quarter wave resonator having a tuned elongated cavity configured to attenuate sound emanating from the marine engine via the plurality of intake runners.

An intake manifold provided in an internal combustion engine to be mounted in a vehicle includes: a plurality of intake-air branch pipes; an EGR chamber configured such that EGR gas is introduced into the EGR chamber; and a plurality of EGR ports communicating the plurality of intake-air branch pipes with the EGR chamber. A chamber bottom face is provided with a plurality of recessed zones so as to correspond to the plurality of EGR ports, each of the plurality of recessed zones is provided near an opening of its corresponding EGR port on an chamber side, and all planes constituting the each of the plurality of recessed zones is configured to be inclined so as to be placed on a mounting lower side toward a position closer to the opening, as compared with a position away from the opening.

An intake manifold provided in an internal combustion engine to be mounted in a vehicle includes: a plurality of intake-air branch pipes; an EGR chamber configured such that EGR gas is introduced into the EGR chamber; and a plurality of EGR ports communicating the plurality of intake-air branch pipes with the EGR chamber. A chamber bottom face is provided with a plurality of recessed zones so as to correspond to the plurality of EGR ports, each of the plurality of recessed zones is provided near an opening of its corresponding EGR port on an chamber side, and all planes constituting the each of the plurality of recessed zones is configured to be inclined so as to be placed on a mounting lower side toward a position closer to the opening, as compared with a position away from the opening.

An air intake device includes: an air intake valve provided so as to change intake air by rotation of a rotation shaft; an actuator which is a driving source for rotating and driving the rotation shaft of the air intake valve; a first link member rotatable by a predetermined operation angle about the rotation shaft; a second link member rotatably connected to the first link member; a connection member which connects the first link member and the second link member so as to be rotatable to each other; and a biasing member whose one side end is engaged to the first link member and whose other side end is engaged to the second link member or the connection member to bias the first link member and the second link member or the connection member so that rattling between the first link member and the second link member is suppressed.

Various methods and systems are provided for an intake manifold for an engine. In one example, an insert comprises an annular body having a top surface, bottom surface, inner surface, and outer surface. The insert further comprises a first groove for coupling an intake air port of an intake manifold to a cylinder head, a second groove for circulating gaseous fuel received from a gas runner of the intake manifold, and one or more openings to fluidically couple the second groove to an interior of the intake air port. The insert is configured to mix gaseous fuel and intake air at a coupling location between the intake manifold and the cylinder head.

Various methods and systems are provided for an intake manifold for an engine. In one example, an insert comprises an annular body having a top surface, bottom surface, inner surface, and outer surface. The insert further comprises a first groove for coupling an intake air port of an intake manifold to a cylinder head, a second groove for circulating gaseous fuel received from a gas runner of the intake manifold, and one or more openings to fluidically couple the second groove to an interior of the intake air port. The insert is configured to mix gaseous fuel and intake air at a coupling location between the intake manifold and the cylinder head.

An air intake manifold for an internal combustion engine having a top shell and a base weldment. The base weldment is formed by permanent joining of a bottom shell having a plurality of air outlets with a runner assembly having a plurality of runner components each having an air inlet and an air outlet, wherein the plurality of runner components are attached to one another via a support member to form the runner assembly.

An air intake manifold for an internal combustion engine having a top shell and a base weldment. The base weldment is formed by permanent joining of a bottom shell having a plurality of air outlets with a runner assembly having a plurality of runner components each having an air inlet and an air outlet, wherein the plurality of runner components are attached to one another via a support member to form the runner assembly.

The disclosure relates to a method for operating a supercharged internal combustion engine having at least one cylinder group with a number n of combustion chambers, wherein, during a first operating state, all n combustion chambers are supplied with combustion air via a primary charge air path and, during a second operating state, only a portion of the n combustion chambers are supplied with combustion air from the primary charge air path and another portion of the n combustion chambers are supplied with combustion air from a separate compressed air reservoir.