Intake manifold for engine

An intake manifold for an engine, comprising:

• a surge tank having a longitudinal direction which defines an upstream side and a downstream side of said surge tank, said surge tank being connected at the upstream side thereof to a throttle valve, said surge tank comprising
• a plurality of branch pipes arranged side by side in the longitudinal direction and respectively connected to cylinders, and
• a bottom wall having at least one protruding part that protrudes upward from the bottom wall, said at least one protruding part including the most upstream protruding part in the longitudinal direction located on the most upstream side;
• and
• a PCV chamber disposed in said surge tank on the upstream side, which is upstream of a central part of said surge tank in the longitudinal direction, said PCV chamber comprising
• a blowby gas introduction port configured to introduce blowby gas into said PCV chamber,
• a blowby gas exhaust port configured to discharge the blowby gas from said PCV chamber into said surge tank, and
• a drain hole configured to discharge water contained in the blowby gas from said PCV chamber into said surge tank, wherein
• said blowby gas exhaust port is located upstream of the most upstream protruding part in the longitudinal direction, and
• said drain hole is located downstream of the most upstream protruding part in the longitudinal direction.