An Experimental Study of a Low-Pressure Direct-Injection Stratified-Charge Engine Concept

A concept of axial charge stratification by means of low-pressure wide-angle direct fuel injection at the beginning of compression stroke together, with in-cylinder swirl was investigated. Two types of fuel delivery system were investigated using in-cylinder visualization coupled with a transparent engine. In one system fuel was delivered through an auxiliary poppet valve and in the other system through an air-blast type direct fuel injector. The lean misfire limit with the direct fuel injector was significantly extended up to a 40:1 air/fuel ratio, although a high level of hydrocarbon emission was observed.