An air intake apparatus of a multi-cylinder engine includes an intake air inlet passage, an intake air distribution portion, a plurality of independent intake air passages, and a secondary gas inlet passage. The intake air inlet passage has one end portion attached to a throttle valve, and the other end connected to an intake air distribution portion. The intake air distribution portion has a space therein. The secondary gas inlet passage is connected at a part spaced apart, in the intake air inlet passage, from the throttle valve. The intake air distribution portion has a reflux passage which is a passage that connects the space and a part between the one end portion and the other end in the intake air inlet passage. The reflux passage is a passage which refluxes fresh air and secondary gas introduced from the intake air inlet passage to the intake air inlet passage.

An air intake control apparatus for a vehicle may include an intake passage configured such that a flow pipe for a flow of intake air is divided into first and second division passages and the first and second division passages communicate with the same combustion chamber, a variable valve provided in the first division passage to adjust an opening degree of the first division passage according to an rotation angle of a motor connected to a central shaft of the variable valve, and an operation valve provided in the second division passage to open or close the second division passage by ON/OFF control.

An air intake control apparatus for a vehicle may include an intake passage configured such that a flow pipe for a flow of intake air is divided into first and second division passages and the first and second division passages communicate with the same combustion chamber, a variable valve provided in the first division passage to adjust an opening degree of the first division passage according to an rotation angle of a motor connected to a central shaft of the variable valve, and an operation valve provided in the second division passage to open or close the second division passage by ON/OFF control.

In one example, an air intake system is provided. The air intake system includes a first air inlet duct providing intake air to an engine intake conduit, the first air inlet duct including an opening positioned external to an engine compartment. The air intake system also includes a second air inlet duct positioned upstream of the engine intake conduit and external to the engine compartment, the second air inlet duct including a porous material spanning an opening in the second air inlet duct, the porous material having a plurality of defined openings sized to prevent snow from traveling therethrough and collect on the porous material thereby impeding airflow through the second air inlet duct during snowy and icy conditions.

In one example, an air intake system is provided. The air intake system includes a first air inlet duct providing intake air to an engine intake conduit, the first air inlet duct including an opening positioned external to an engine compartment. The air intake system also includes a second air inlet duct positioned upstream of the engine intake conduit and external to the engine compartment, the second air inlet duct including a porous material spanning an opening in the second air inlet duct, the porous material having a plurality of defined openings sized to prevent snow from traveling therethrough and collect on the porous material thereby impeding airflow through the second air inlet duct during snowy and icy conditions.

In one example, an air intake system is provided. The air intake system includes a first air inlet duct providing intake air to an engine intake conduit, the first air inlet duct including an opening positioned external to an engine compartment. The air intake system also includes a second air inlet duct positioned upstream of the engine intake conduit and external to the engine compartment, the second air inlet duct including a foam plug selectively impeding airflow through the second air inlet duct, the foam plug spanning an opening of the second air inlet duct.

In one example, an air intake system is provided. The air intake system includes a first air inlet duct providing intake air to an engine intake conduit, the first air inlet duct including an opening positioned external to an engine compartment. The air intake system also includes a second air inlet duct positioned upstream of the engine intake conduit and external to the engine compartment, the second air inlet duct including a foam plug selectively impeding airflow through the second air inlet duct, the foam plug spanning an opening of the second air inlet duct.

An internal combustion engine (10), including a cylinder (15) with a cylinder wall (12) defining a combustion chamber (32), a piston (13) reciprocally disposed within the combustion chamber (32) a crankcase (16) including a crankshaft (11) rotatably disposed therein, the piston (13) being connected to the crankshaft (11) by a connecting rod (17), a first scavenger duct (3) extending between the combustion chamber (32) and the crankcase (16), the first scavenger duct (3) including a top port (31a) and a bottom port (31b), a fuel and air inlet channel (22) in fluid communication with the crankcase (16) by way of a piston ported fuel and air inlet port (23) so that the fuel and air inlet channel (22) delivers a fuel and air mixture to the crankcase (16), and an airhead channel (6) in fluid communication with the first scavenger duct (3) by way of a first piston ported air inlet port (7), characterized in that the fuel and air inlet channel (22) is in fluid communication with the airhead channel (6) so that the fuel and air mixture is combinable with the air flow from the airhead channel (6).

An internal combustion engine (10), including a cylinder (15) with a cylinder wall (12) defining a combustion chamber (32), a piston (13) reciprocally disposed within the combustion chamber (32) a crankcase (16) including a crankshaft (11) rotatably disposed therein, the piston (13) being connected to the crankshaft (11) by a connecting rod (17), a first scavenger duct (3) extending between the combustion chamber (32) and the crankcase (16), the first scavenger duct (3) including a top port (31a) and a bottom port (31b), a fuel and air inlet channel (22) in fluid communication with the crankcase (16) by way of a piston ported fuel and air inlet port (23) so that the fuel and air inlet channel (22) delivers a fuel and air mixture to the crankcase (16), and an airhead channel (6) in fluid communication with the first scavenger duct (3) by way of a first piston ported air inlet port (7), characterized in that the fuel and air inlet channel (22) is in fluid communication with the airhead channel (6) so that the fuel and air mixture is combinable with the air flow from the airhead channel (6).

A system in a vehicle includes a primary intake manifold, a secondary intake manifold, a valve, and a computer. The primary and secondary intake manifolds are configured for an engine compartment of the vehicle. The secondary intake manifold is arrangeable to extend from outside the engine compartment to the valve. The valve is connected to each of the primary and secondary intake manifolds. The computer is in communication with the valve and programmed to identify a flood risk and then actuate the valve.