A Contribution to the Improvement of an Open-Chamber Stratified-Charge Engine

The developments of an open-chamber stratified-charge engine are herein described; the aim of this engine is to work at part-loads with low fuel consumption while remaining, however, under acceptable exhaust emissions.The essential purpose of this research has been to markedly amplify the overall air-fuel ratio field in which the engine working is regular. This also serves to modify the engine load by varying the air-fuel ratio instead of air throttling so that the corresponding losses can be avoided.By studying and setting up a proper injector, the fuel injection system has been considerably improved. In fact this injector gives a suitable spray geometry, with particular regard to the spray penetration, the spray angle and the droplet size. Injection pressure and timing have also been investigated in order to optimize engine performance.At present, under wide open throttle conditions, the engine already works with overall air-fuel ratio variable up to four times the stoichiometric value.