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.