Re: air - fuel ratio

On May 8, 1:50=A0pm, N8N <njna...@[EMAIL PROTECTED]
> wrote:
> > 2: Unthrottled operation. In the Diesel cycle load is controlled by
fuel=

> > alone. This reduces gas pumping losses incurred during the
> > intake/exhaust strokes. In future Diesels this may fade somewhat as
> > throttling is being used to facilitate achieving the EGR levels needed
> > to meet oxides of nitrogen regulations.

>
> What he said. =A0I'm not sure how much 2) contributes, but sort of as an
> aside, this is the reason why you see sewer-pipe sized exhaust pipes
> on Diesel vehicles - they are essentially pumping the full
> displacement of the engine (or more, if supercharged) of air through
> the engine every two revolutions, unlike a gasoline engine where this
> only happens at WOT.

and why they can sit and idle all day on a teaspoon of fuel.