Abstract: A suction system for a V-type engine includes branch pipes that cross parallel to each other for communicating with cylinders, two aggregate portions disposed inside center lines of opposed banks for aggregating the branch pipes which communicate with the cylinders without regard to the ignition order, two guide pipes connected to the aggregate portions in centers thereof, and a communicating pipe disposed over the branch pipes for communicating with the aggregate portions.

Abstract: An intake system for a V-type internal combustion engine has two banks. To keep the same charging efficiency between right and left banks of the engine, the divided portions of the air duct are formed to be the same in passage length by bending one of the divided portions of the air duct in a U-shape. Furthermore, the U-shaped part is disposed above a cooling fan to reduce the ventilation resistance of the U-shaped part by cooling the intake air passing through the U-shaped part.

Abstract: An intake system of a V-type internal combustion engine equipped with a turbocharger. The intake system is has an air intake passageway which is branched at a branched section into first and second downstream air intake passageways which are respectively communicable with first and second banks of the engine. First and second throttle valves are disposed respectively in the first and second downstream air intake passageways. Intake air is bypassed from the branched section through the air bypass passage to an upstream side of the turbocharger compressor when the throttle valves are closed in order to prevent an excessive pressure rise in an upstream side of the throttle valves. The air flow through the air bypass passage is controlled by an air bypass valve disposed in the air bypass passage near the branched section.

Abstract: An intake system for a V-type internal combustion engine having two banks. The intake system is comprised of two sub-collectors disposed above the respective two banks of the engine and fluidly connected with cylinders in the banks. A main collector is disposed above and between the two banks of the engine and fluidly connected through a throttle device with the two sub-collectors. The main collector is supplied with air from an air filter. The throttle device is located at the rear end side of the engine and has throttle valves which respsectively control air flows to the two sub-collectors in response to operation of an accelerator pedal.

Abstract: Each combustion chamber of the engine is communicated with (a) first and second induction passages which are dimensioned to produce an optimal ramming effect during high speed and (b) a third passage which provides good ramming during low engine speed operation. The first and second induction passages are provided with flow control valves which can be opened simultaneously or in a step-wise manner as the engine speed moves from a low speed range into a high speed one. The third passage is arranged to merge with the first so that during idling and the like, the flow of air therefrom enters the combustion chamber in a manner which produces a strong swirl and promotes good atomization of the fuel injected into the first passage by a fuel injector.