New Method of Improving Intake Port Flow Characteristics in a Four-Valve Engine
A 1arge-scale tumble rather than swirl would exist in the cylinder in the case of two valves’ opening in a four-valve engine. A strong swirl was generated when one valve is closed, but the flow capacity was less than that of two valves opening. In order to change it, achieving different lifts of valves (DLV) was present. Both tumble and swirl would exist in the cylinder in the case of different lifts of two intake valves, and flow capacity will hardly change.
Daoguo Yang, Tianlong Gu, Huaiying Zhou, Jianmin Zeng and Zhengyi Jiang
S. Q. Zhang et al., "New Method of Improving Intake Port Flow Characteristics in a Four-Valve Engine", Advanced Materials Research, Vols. 201-203, pp. 2186-2189, 2011