Effects of Helical Port with Swirl Control Valve on the Combustion and Performance of S. I. Engine

A helical port with a swirl control valve (SCV) has been developed to satisfy two inconsistent requirements of achieving sufficient swirl generation to improve the combustion and still maintaining high volumetric efficiency.

Their effects on combustion were confirmed in a single cylinder engine using high speed flame photography and cylinder pressure diagram analysis which has demonstrated faster combustion.

As a result of a hot wire anemometer study, the differences in gas motion were clarified between two helical ports, one with and one without a SCV. A more active movement of the center of swirl was measured in the case of helical port with SCV which suggests the generation of higher turbulence in the cylinder.