JPH0235854B

PURPOSE:To make variable the effective length of intake tube easily by arranging an intake manifold between cylinder rows at the right and left of V-type multi-cylinder internal-combustion engine while constructing it with high and low intake paths. CONSTITUTION:An intake manifold M is arranged through a groove V between the left and right cylinder rows C, C of V-type 6-cylinder engine for the purpose to distribute the intake-air to three intake ports 141-143 in the left and right cylinder rows C. Said manifold M is comprised of common intake distribution chamber 16, high speed intake paths 171-173 extending from one side of said chamber 16 to each intake port 141-143 and low speed intake paths 181-183 extending from the other side of said chamber 16 to be coupled to the sections b1-b3 branched from the intermediate section of intake path 171-173. Valves 241-243 for opening/closing each high speed intake path 171-173 are provided on an intermediate board P placed at the intermediate section of said manifold M to vary the effective length of intake tube through opening/closing of said valves 241-243.