INTAKE PORT FLOW CONTROL DEVICE

摘要

A helically-shaped intake port comprising a helical portion formed around an intake valve and a substantially straight inlet passage portion tangentially connected to the helical portion. A bypass passage is branched off from the inlet passage portion and connected to the helical portion. A rotary valve is arranged in the bypass passage and actuated by a vacuum operated diaphragm apparatus. The rotary valve is opened when the amount of air fed into the cylinder of an engine is increased beyond a predetermined value. A cooling water passage is arranged beneath and near the bypass passage.