Charge Stratification in a 4-Valve SI Engine Through Injection Into One Intake Port with Induced Axial Swirl Within the Cylinder

An arrangement of port - injected, stratified-charge, 4 - valve SI engine is proposed, in which fuel is injected in a thin column from an injector which is angled so that the fuel is deflected by one of the inlet valves onto the combustion chamber surface, at a position close to the central spark plug. The injection takes place towards the end of the induction stroke, and the injector is mounted to the side of one of the intake ports. The second intake port is deactivated at part load to establish an axial swirling motion to stabilise the fuel evaporating from the warm combustion chamber surface.

Testing has been performed on a single - cylinder research engine to assess the extent of the stratification by measuring pre - flame hydrocarbon concentrations at various positions around the combustion chamber. Further testing using high - speed cine photography applied to the research engine has allowed a study to be made of the trajectory of liquid fuel within the combustion chamber with the stratified charge arrangement.