Study on Air Flow Characteristics in Cylinders of a Four-Valve Engine with Different Lifts of Valves

Shiqiang Zhang*, 1, Xianghong Zhang1, Huigang Wang1, Ruilin Liu2, Wuquan Liu2, Guangmeng Zhou2, Miao Chi2
1 Department of Electro-Mechanical Engineering, Tangshan College, Tangshan 063000, China
2 Automobile Engineering Department, Military Transportation University, Tianjin 300161, China

© 2014 Zhan et al

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: ( This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Department of Electro- Mechanical Engineering, Tangshan College, Tangshan 063000, China; Tel: +86-0315-2010536; Fax: +86-0315-2010536; E-mail:


A 1arge-scale tumble rather than swirl would exist in cylinders in the case of two valves’ opening in a fourvalve engine. A strong swirl is generated when one valve is closed, yet the flow capacity is less than that of two valves being opened. In order to change it, different lifts of valves (DLV) present are achieved. In the case of using different lifts of two intake valves, both tumble and swirl would occur in cylinders, and the flow capacity will hardly change. A new method of measuring the rotational speed of the intake swirl –the method of virtual rotational speed of theory has been put forward. Not only does it eliminate the influence of frictional resistance, but also obtain a theoretic rotational speed, which is only produced by intake swirl.

Keywords: Different lifts of valves, engine, swirl, virtual rotational speed of theory.