An air intake device with a variable-length intake duct, comprising: a base duct component with a base duct, configured for the passage of intake air through the base duct component, an extension duct component with an extension duct, configured for the passage of intake air through the extension duct component, a guidance arrangement which guides the extension duct component and the base duct component to relative movement between a first operating position and a second operating position, wherein in the first operating position the base duct and the extension duct form, in mutually prolonging abutment, a continuous duct section, and wherein in the second operating position the extension duct is arranged at a distance from the base duct, and a first centering arrangement which when the duct components approach the first operating position is configured to decrease a radial distance in relation to a virtual base duct path conceived as passing centrally through the base duct between an end section of the base duct facing towards the extension duct component and an end section of the extension duct facing towards the base duct component, wherein the first centering arrangement is configured as separate from the base duct and from the extension duct.

The presently disclosed subject matter is generally directed to a system and method of protecting the engines of ATVs by preventing excessive water from entering the belt drive and/or air intake of the vehicle motor. The system includes a riser and valve assembly. Each snorkel valve assembly includes one or more water sensors in communication with a valve. When water is detected by the sensors, the valve closes, preventing water from entering the vehicle engine, transmission, air box, clutch housing, and/or any other vented element of the ATV engine. Instead, the water is diverted out of the system through a drain valve. Accordingly, the system prevents water, mud, and the like from entering the main components of the ATV motor.

A hood air intake and water separation system includes a first separation chamber having a first inlet fluidly coupled to a hood intake vent of the vehicle, a first outlet, and at least one first drain opening. The first separation chamber is configured to separate water and air ingested through the intake and direct the separated water through the at least one first drain opening and direct the separated air through the first outlet. A second separation chamber includes a second inlet fluidly coupled to the first separation chamber first outlet, a second outlet, and at least one second drain opening. A third chamber includes a third inlet fluidly coupled to the second separation chamber second outlet, and a third outlet. The first and second separation chambers are configured to direct ingested water away from an airpath to the engine.

An intake system for an internal combustion engine may include an air inlet; a forced induction device downstream from the air inlet; an intercooler downstream from the forced induction device; and an intake conduit configured to guide air from the intercooler to an internal combustion engine. In addition, the system may include a condensate retaining structure associated with the intake conduit and configured to restrict the flow of condensate through the intake conduit.

An air intake structure for introducing an intake air into an engine includes: a first air intake passage fluidly connected with an air outlet; a second air intake passage branched off from the first air intake passage and having a passage length greater than that of the first air intake passage; and an open-close valve provided in the first air intake passage. The second air intake passage has a portion thereof bent to allow the flow of intake air in one direction reverse to that of the air flowing a different portion thereof. The first air intake passage, the second air intake passage and the open-close valve are provided within an air cleaner.

An intake-air temperature controlling device for an engine is provided, which includes an engine body, an intake passage, an air intake part, an intake air temperature adjuster configured to adjust air temperature taken in through the air intake part to the passage, and a controller. An operating range in which the CI combustion is performed has a lean operating range in which A/F of mixture gas formed inside the cylinder, or G/F that is a relationship between the total weight G of gas inside the cylinder and a weight F of fuel fed to the cylinder is relatively low, and a rich operating range in which the A/F or G/F is relatively high. When the engine is in the lean operating range, the controller outputs a control signal to the intake air temperature adjuster so that the air temperature is increased, as compared in the rich operating range.

A heat storage cover is provided in an engine room. The heat storage cover covers an engine from above and surrounds the periphery of an upper portion of the engine to internally store, through the medium of air, heat dissipated from the engine and block upward heat dissipation. The engine includes an air inlet for introducing, into a combustion chamber, high temperature air obtained by the heat storage cover blocking the upward heat dissipation.

An intake duct has a front-rear two-split structure, and includes a rear duct connected to a body frame and a front duct connected to the rear duct. The rear duct includes a body frame connection portion that is connected to the body frame and is attached with a rear stay that supports a cowl and a meter, and the front duct is directed forward from the rear duct.

A vehicle that can realize measures for water exposure of intake ducts by a simple configuration is provided. The vehicle has a front seat, an engine and a continuously variable transmission at least partially located on a rear side of a front-end of the front seat and a bottom side of a lower end of the front seat, intake ducts at least partially extending from a rear side toward a front side on the bottom side of the lower end of the front seat, having intake ports in front-end portions, and sending outside air taken in from the intake ports to the continuously variable transmission, and a front cover covering both the front-end portions of the intake ducts, wherein the front-end portions of the intake ducts are located on a front side of the front-end of the front seat and a top side of the lower end of the front seat.

A vehicle includes an internal combustion engine and an air induction system configured to provide intake air to the internal combustion engine. The air induction system includes an intake port, an air box coupled to the intake port and having a wet side air box and a dry side air box, at least one sensor disposed within the air box and configured to detect a presence or level of liquid within the air box, and a watertight door disposed within the air box and configured to move between an open position that allows air to pass through the air box dry side, and a closed position that facilitates preventing liquid from passing into the air box dry side.