An intake port may include a short port and a long port. The short port may include a main extension portion extending from an intake air inlet; a main inclined portion inclined at a predetermined angle from the main extension portion toward a center of a cylinder; a main vertical portion bending downward toward the cylinder from the main inclined portion; and a main intake air outlet formed at an end portion of the main vertical portion. The long port may include an auxiliary extension portion extending from the main extension portion; an auxiliary inclined portion which is inclined at a predetermined angle from the auxiliary extension portion toward the center of the cylinder and inclined at a predetermined angle downward toward the cylinder; an auxiliary vertical portion bending downward from the auxiliary inclined portion; and an auxiliary intake air outlet at an end portion of the auxiliary vertical portion.

An apparatus and a method are provided for an air intake assembly configured for use with Pro Stock vehicles comprising fuel injection equipped engines. The air intake assembly comprises an air inlet that includes a distal opening disposed in a forward direction at a front of the vehicle and configured to direct incident air into the air intake assembly. An air duct is joined with the air inlet by way of a first coupler configured to maintain an airtight seal between the air inlet and the air duct. A throttle body adapter is joined with the air duct by way of a second coupler configured to maintain an airtight seal therebetween. The throttle body adapter is configured to establish an airtight coupling between the air intake assembly and a throttle body of the engine, such that the incident air is directed into the throttle body.

An intake duct for an internal combustion engine includes a tubular side wall. The side wall includes a first split body and a second split body that are separate from each other in a peripheral direction of the side wall. The first split body includes a rib that divides an inside of the side wall into passages and extends in an extending direction of the side wall. A distal end of the rib in a protruding direction of the rib is spaced apart from an inner surface of the second split body. A portion of the second split body opposed to the distal end is provided with a breathable part that allows air to flow between the inside and an outside of the side wall.

An apparatus and a method are provided for an air intake assembly configured for use with Pro Stock vehicles comprising fuel injection equipped engines. The air intake assembly comprises an air inlet that includes a distal opening disposed in a forward direction at a front of the vehicle and configured to direct incident air into the air intake assembly. An air duct is joined with the air inlet by way of a first coupler configured to maintain an airtight seal between the air inlet and the air duct. A throttle body adapter is joined with the air duct by way of a second coupler configured to maintain an airtight seal therebetween. The throttle body adapter is configured to establish an airtight coupling between the air intake assembly and a throttle body of the engine, such that the incident air is directed into the throttle body.

In an air cleaner for a vehicle, a connection part of a first intake duct to a cleaner case is disposed in a front half portion of one of left and right half portions of the cleaner case, the first intake duct including a first air inlet port opening forward. A connection part of a second intake duct to the cleaner case is disposed in a rear half portion of an other of the left and right half portions, the second intake duct including a second air inlet port opening rearward. The first intake duct is formed to include a first air outlet port opening rearward inside an unpurified chamber and curve in an up-down direction in a side view, and the second intake duct is formed to include a second air outlet port opening forward inside the unpurified chamber and curve in a right-left direction in a plan view.

Methods and systems are provided for a convolute-swirl integrated duct (CSID). In one example the CSID may be configured to comply with engine roll and induce swirl in an intake air flow. Engine roll is absorbed as a result of a positioning of the CSID along an intake passage upstream of a compressor inlet and pre-whirl is introduced to intake air prior to delivery of the intake air to a compressor.

An air intake structure for a saddled vehicle including a downsized air cleaner box and a sufficient intake path is provided.

An air intake structure for a saddled vehicle applied to a saddled vehicle including an engine suspended from a vehicle body frame and an air cleaner box disposed behind the engine includes: a side cover mounted on a sidewall on an outer side in the vehicle width direction of the air cleaner box; and a side cover opening formed at the side cover toward the vehicle rear side. Outside air to be taken into the air cleaner box is taken from the side cover opening. The sidewall is provided with an intake opening, and the intake opening is covered with the side cover. The side cover includes a body that covers the sidewall, and a canopy member provided at the surface of the body. The side cover opening is formed of the outer edge of the canopy member.

A flow rate measuring device measures a flow rate of a main flow flowing through a duct. The flow rate measuring device includes a bypass passage, a flow rate sensor, and a measurement body. The measurement body includes a measurement flow inlet opening toward an upstream side of the duct and a cylindrical portion opening toward a downstream side of the duct. The cylindrical portion is disposed to cover the measurement flow outlet. The cylindrical portion includes an outer circumferential surface guiding the main flow and an inner circumferential surface guiding the measurement flow. The cylindrical portion includes a waveform portion formed in an edge side of an opening of the cylindrical. The waveform portion divides the main flow guided by the cylindrical portion into a plurality of main flows and divides the measurement flow guided by the cylindrical portion into a plurality of measurement flows.

A partition plate is configured to separate an intake passage formed by an intake pipe to be coupled to a combustion chamber into a first intake passage and a second intake passage. The first intake passage is openable and closable by a valve. A shape of a first cross section orthogonal to an extending direction of the intake pipe is set on the basis of a shape of a surface of the intake pipe that faces the partition plate with the second intake passage interposed therebetween.

An air intake port (10) for a lean-burn gasoline engine (110) comprises an air inlet (14), two air outlets (15a, 15b), and an air channel connecting the air inlet (14) to the two air outlets (15a, 15b) and comprising an upstream common duct (11) and two downstream port legs (12a, 12b), the two downstream port legs (12a, 12b) branching off from the common duct (11) at a bifurcation point (13). A total cross section of the air intake port (10) gradually decreases between the air inlet (14) and the two air outlets (15a, 15b). A gradient of decrease of the total cross section is locally reduced in a region adjacent the bifurcation point (13).