air-assisted injectors, sort of

Greg Hermann bearbvd at sni.net
Tue Sep 1 18:09:47 GMT 1998


>Actually, for all intents and purposes the mixtures at the extreme A/F
>ratios aren't mixtures at all.  The direct injection allows stratified
>charging, actually close to stoich at the spark plug - pure air in the rest
>of the cylinder.  The low load conditions where DI is most advantageous
>actually inject after BDC on compression stroke (4- and 2-stroke) to avoid
>mixing.  The heat rejection with highly lean mixtures at low load increases
>efficiency to get fuel economy up.
>
>John Bucknell

Amen. Plus, the wider throttle opening relative to load serves to decrease
pumping work, and thus boost BSFC.

Regards, Greg
>
>
>





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