A guide element for a pressure system of an internal combustion engine has a hollow body with a guide element inlet (27), a guide element outlet (28) and a longitudinal axis (26). The guide element (25) is designed so that flow can pass through it along its longitudinal axis (26). To eliminate disruptive oscillations, the guide element (25) is of streamlined form in a flow direction from the guide element inlet (27) to the guide element outlet (28). A pressure system for an intake tract of an internal combustion engine and an internal combustion engine with a supercharging unit also are provided.

An assembling structure for an intake manifold includes: a first downstream portion; a second downstream portion; an upstream portion; a connecting member that connects the first downstream portion and the second downstream portion with each other; and a plate-shaped stay. The connecting member is fixed to the first downstream portion and the second downstream portion by a bolt, and an other member that is a member other than the intake manifold is fixed to the intake manifold through the stay at least either between the connecting member and the first downstream portion, or between the connecting member and the second downstream portion.

An assembling structure for an intake manifold includes: a first downstream portion; a second downstream portion; an upstream portion; a connecting member that connects the first downstream portion and the second downstream portion with each other; and a plate-shaped stay. The connecting member is fixed to the first downstream portion and the second downstream portion by a bolt, and an other member that is a member other than the intake manifold is fixed to the intake manifold through the stay at least either between the connecting member and the first downstream portion, or between the connecting member and the second downstream portion.

A variable intake system includes a pair of surge tanks connected in a communicating manner to a main intake pipe through a low speed communication pipe and a high speed communication pipe, a middle speed communication pipe for connecting the pair of surge tanks, and a noise reducing member integrally provided at the middle speed communication pipe to reduce noise.

A variable intake system includes a pair of surge tanks connected in a communicating manner to a main intake pipe through a low speed communication pipe and a high speed communication pipe, a middle speed communication pipe for connecting the pair of surge tanks, and a noise reducing member integrally provided at the middle speed communication pipe to reduce noise.

An internal combustion engine includes a crankcase including a crankshaft and at least one cylinder coupled to the crankcase. The at least one cylinder has an intake port and defines an internal combustion chamber. The engine further includes a throttle body assembly with a throttle valve coupled to the intake port of the at least one cylinder and a throttle plate. Additionally, the engine includes a supplementary air inlet fluidly coupled to the intake port and spaced apart from the throttle valve. The supplementary air inlet is configured to receive a flow of air from a location downstream of the throttle plate when the throttle plate is in a fully closed position and the flow of air is directed into the combustion chamber through the intake port for combustion therein.

An outboard motor engine has a cylinder block including vertically stacked cylinders divided into two cylinder banks arranged in a V-shape. Two cylinder heads define intake passages, each intake passage corresponding to a respective cylinder. Air intake manifolds include air intake runners that extend from an opposite end of the engine, around outer sides of the cylinder block, and respectively connect to the intake passages. Two vertically extending fuel rails are respectively located between the first cylinder head and the first air intake manifold and between the second cylinder head and the second air intake manifold. The fuel rails are integral with either the respective cylinder heads, or the respective air intake manifolds. Fuel injectors are coupled to the fuel rails and vertically spaced from one another with respect to each fuel rail such that each fuel injector is associated with a respective cylinder.

An outboard motor engine has a cylinder block including vertically stacked cylinders divided into two cylinder banks arranged in a V-shape. Two cylinder heads define intake passages, each intake passage corresponding to a respective cylinder. Air intake manifolds include air intake runners that extend from an opposite end of the engine, around outer sides of the cylinder block, and respectively connect to the intake passages. Two vertically extending fuel rails are respectively located between the first cylinder head and the first air intake manifold and between the second cylinder head and the second air intake manifold. The fuel rails are integral with either the respective cylinder heads, or the respective air intake manifolds. Fuel injectors are coupled to the fuel rails and vertically spaced from one another with respect to each fuel rail such that each fuel injector is associated with a respective cylinder.

A first downstream part of an intake manifold has a first downstream passage configured to communicate with an intake port of a first cylinder head. A second downstream part of the intake manifold has a second downstream passage configured to communicate with an intake port of a second cylinder head. An upstream part is coupled to the first downstream part and the second downstream part. The upstream part is arranged upstream from the first and second downstream parts in the flow direction of intake air and has a first upstream passage and a second upstream passage. The material of the first downstream part and the material of the second downstream part both have higher rigidity than the material of the upstream part.

A first downstream part of an intake manifold has a first downstream passage configured to communicate with an intake port of a first cylinder head. A second downstream part of the intake manifold has a second downstream passage configured to communicate with an intake port of a second cylinder head. An upstream part is coupled to the first downstream part and the second downstream part. The upstream part is arranged upstream from the first and second downstream parts in the flow direction of intake air and has a first upstream passage and a second upstream passage. The material of the first downstream part and the material of the second downstream part both have higher rigidity than the material of the upstream part.