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 embodiment variable valve device of a vehicle intake system includes a variable valve housing fixed to a housing of an air cleaner and including a valve passage penetrating the air cleaner, a variable valve flap rotatably coupled to the variable valve housing and configured to perform opening and closing operations based on an intake negative pressure of an engine to open and close the valve passage, and a cam protrusion and a leaf spring provided on the variable valve flap and the variable valve housing, respectively, wherein the cam protrusion and the leaf spring are in contact with each other.

An embodiment variable valve device of a vehicle intake system includes a variable valve housing fixed to a housing of an air cleaner and including a valve passage penetrating the air cleaner, a variable valve flap rotatably coupled to the variable valve housing and configured to perform opening and closing operations based on an intake negative pressure of an engine to open and close the valve passage, and a cam protrusion and a leaf spring provided on the variable valve flap and the variable valve housing, respectively, wherein the cam protrusion and the leaf spring are in contact with each other.

Disclosed herein is a method and an insert device for an internal combustion engine including: a central exhaust passage; a first expansion chamber in an upstream portion of the exhaust system and in fluidic communication with the central exhaust passage; a second expansion chamber in a downstream portion of the exhaust system and in fluidic communication with the central exhaust passage and the first expansion chamber, forming a continuous expansion chamber throughout a length of the insert device.

A control device for an engine, the engine includes an exhaust gas control apparatus that is configured to store NOx and react NOx with a reduction agent. The control device includes an electronic control unit. The electronic control unit is configured to: (i) execute a rich spike control, the rich spike control is a control executed to temporarily change an in-cylinder air-fuel ratio from a leaner air-fuel ratio than the stoichiometric air-fuel ratio to the stoichiometric air-fuel ratio or a richer air-fuel ratio than the stoichiometric air-fuel ratio, and (ii) vary an overlap amount of an intake valve and an exhaust valve such that the overlap amount is less during non-execution of the rich spike control than during execution of the rich spike control, in an operation range where a pressure of the intake port becomes higher than a pressure of the exhaust port.

An intake control valve includes a valve body being made of resin, the valve body configured to be pivotally mounted to a surge tank of an internal combustion engine, the valve body pivoting between an open position and a closed position to for opening and closing a fluid passage formed at a division wall, the division wall dividing inside of the surge tank into two portions; and a bearing being made of metal, the bearing being integrally provided with a first end portion of the valve body by insert molding when resin molding the resin-made valve body.

A charge air line of an internal combustion engine for supplying multiple cylinders of a cylinder bank of the internal combustion engine arranged in-line with charge air, has multiple charge air line sections. Emanating from each charge air line section a branch leads to a cylinder, the branch screwable to a cylinder head of the respective cylinder. The charge air line has an upstream end, via which charge air is feedable to the charge air line, and a downstream end, which is closed by an end cap. At the downstream end, the charge air line has a larger flow cross section than at the downstream end.

A charge air line of an internal combustion engine for supplying multiple cylinders of a cylinder bank of the internal combustion engine arranged in-line with charge air, has multiple charge air line sections. Emanating from each charge air line section a branch leads to a cylinder, the branch screwable to a cylinder head of the respective cylinder. The charge air line has an upstream end, via which charge air is feedable to the charge air line, and a downstream end, which is closed by an end cap. At the downstream end, the charge air line has a larger flow cross section than at the downstream end.

A variable intake system for a vehicle is provided and includes an air cleaner that filters air via a filter and supplies the air to an engine. A main duct is connected to the air cleaner to supply the air, and a variable valve has a housing that is coupled and mounted to a mounting aperture of a mounting part disposed on a front end of the filter of the air cleaner. An internal passage of the housing is opened by suction pressure of the engine in the mounting part to suction external air. A projection formed on the housing of the variable valve is inserted into a projection seat formed in the mounting part, so that the variable valve is secured to the mounting part.

Internal combustion engines having an external mixture formation and compensation tank for avoiding reignition. An internal combustion engine is provided having an external mixture formation including at least one exhaust system, at least one intake system, the intake system including at least one intake manifold, at least one throttle valve, at least one mixture forming device, at least one compensation tank, and at least one air filter.