An engine system may include: an engine including cylinders that generate a driving torque by combusting fuel; a first intake manifold connected to an intake line through which flows intake air into some of the plurality of cylinders; a second intake manifold supplying the intake air to the other cylinders of the plurality of cylinders through the first intake manifold; a first exhaust manifold connected to some cylinders that are connected to the first intake manifold; a second exhaust manifold connected to some other cylinders that are connected to the second intake manifold; a recirculation line branched from the second exhaust manifold to be coupled to the second intake manifold; a recirculation inlet valve disposed at a point at which the recirculation line and the second exhaust manifold are joined; and a manifold connection valve disposed on an intake line between the first intake manifold and the second intake manifold.

An engine device having gas injectors attached to an intake manifold fixed to a side surface of a cylinder head. A fuel gas injected from the gas injectors is premixed in the intake manifold, and the resulting gas is supplied to a plurality of cylinders and ignited by ignition devices. The intake manifold has a configuration in which a plurality of intake branch pipes communicating with the cylinders are branched from an intake collecting pipe at an air supply side. The intake branch pipes include bent portions. In the bent portions of the intake branch pipes, inside inner walls near the cylinder head are bent at an acute angle.

An air intake passage (30) has a third passage (37) that connects an intercooler (36) and a bottom portion of a surge tank (38) such that the intercooler (36) is positioned below the surge tank (38). A pair of wall portions (71, 72) configured to catch moisture is formed in a section from an upstream end portion of the third passage (37) to a connected portion between said third passage (37) and the surge tank (38).

An air intake passage (30) has a third passage (37) that connects an intercooler (36) and a bottom portion of a surge tank (38) such that the intercooler (36) is positioned below the surge tank (38). A pair of wall portions (71, 72) configured to catch moisture is formed in a section from an upstream end portion of the third passage (37) to a connected portion between said third passage (37) and the surge tank (38).

An intake manifold including a surge tank having an inlet and a plurality of outlets extended along a first direction, and configured to form a space having a cross section larger than the inlet between the inlet and the plurality of outlets and a plurality of branch pipes. The space is formed by a bottom surface, an upper surface, a first surface extended from a first end of the bottom surface to a first end of the upper surface, and a second surface extended from a second end of the bottom surface to a second end of the upper surface. The inlet is provided at a substantially central portion in a first direction on the first surface, and the bottom surface includes a swelling portion swelled upwardly at a substantially central portion in the first direction.

An intake assembly for an internal combustion engine, includes an intake manifold including a first plenum and a plurality of intake runners, the first plenum including an air supply inlet, the intake runners configured to be couplable to a cylinder head of the engine for supplying an air-fuel mixture thereto, the intake manifold configured such that, in use, air is supplied from the air supply inlet to the intake runners via the first plenum; a plurality of fuel injectors, each arranged to inject a fuel into one of the intake runners; and a fuel rail coupled to the plurality of fuel injectors, the fuel rail including a fuel supply inlet, and configured to supply fuel from the fuel supply inlet to the plurality of fuel injectors, in use. The fuel rail is mounted to the first plenum.

An intake assembly for an internal combustion engine, includes an intake manifold including a first plenum and a plurality of intake runners, the first plenum including an air supply inlet, the intake runners configured to be couplable to a cylinder head of the engine for supplying an air-fuel mixture thereto, the intake manifold configured such that, in use, air is supplied from the air supply inlet to the intake runners via the first plenum; a plurality of fuel injectors, each arranged to inject a fuel into one of the intake runners; and a fuel rail coupled to the plurality of fuel injectors, the fuel rail including a fuel supply inlet, and configured to supply fuel from the fuel supply inlet to the plurality of fuel injectors, in use. The fuel rail is mounted to the first plenum.

An air intake apparatus includes a plurality of funnel-shaped portions provided in a plurality of intake ports. The plurality of funnel-shaped portions respectively include open ends located at positions at which lengths of the plurality of intake ports are aligned with each other, the open ends being provided along a direction perpendicular to a direction in which respective centerlines of the plurality of intake ports extend.

An air intake apparatus includes a plurality of funnel-shaped portions provided in a plurality of intake ports. The plurality of funnel-shaped portions respectively include open ends located at positions at which lengths of the plurality of intake ports are aligned with each other, the open ends being provided along a direction perpendicular to a direction in which respective centerlines of the plurality of intake ports extend.

The present disclosure aims to improve circulation of intake air and distribution of bypass intake air to cylinders, while reducing an increase in the overall height of an engine. A supercharger extends along a cylinder bank at a side of a surge tank extending along the cylinder bank. A bypass pipe branching off from an upstream intake pipe configured to introduce the intake air into the supercharger extends along the cylinder bank above the supercharger. A downstream side intake pipe configured to guide the intake air from the supercharger to the surge tank extends downward from the supercharger. The downstream intake pipe is, in a U-shape as viewed along the cylinder bank, connected to the surge tank.