Abstract: An air inlet manifold for a multi-cylinder internal combustion engine having a distribution chamber restricted by at least a first internal wall and a plurality of pipe channels each restricted by at least a second internal wall, which pipe inlet is described by a first surface with a first area restricted by a first line in the boundary between the pipe inlet and the first internal wall The pipe channel is described by a second surface with a second area restricted by a second line along the perimeter of the pipe channel, the second surface is generally perpendicular to the extension direction of the pipe channel. A profile between the first line and the second line in a pipe located proximate to the air inlet has a different curvature than a profile between the first line and the second line in a pipe located distant from the air inlet.

Abstract: The invention relates to an air inlet manifold for a multi-cylinder internal combustion engine having a distribution chamber restricted by at least a first internal wall and a plurality of pipe channels each restricted by at least a second internal wall, which pipe inlet is described by a first surface with a first area restricted by a first line in the boundary between the pipe inlet and the first internal wall The pipe channel is described by a second surface with a second area restricted by a second line along the perimeter of the pipe channel, the second surface is generally perpendicular to the extension direction of the pipe channel. A profile between the first line and the second line in a pipe located proximate to the air inlet has a different curvature than a profile between the first line and the second line in a pipe located distant from the air inlet.