[Vwdiesel] Atkinson/Miller cycle diesel

[Tad]

what I understand about Atkinson, the point is not to reduce
temperature/pressure; that is merely a means to an end.

The point of the Atkinson is to increase efficiency by lengthening the
power stroke and thereby extracting more energy from the combustion.
 Leaving the intake open longer lowers the effective compression ratio but
without the corresponding reduction in power stroke length that you would
have if you just lowered compression the conventional way.

If you did this without messing with the intake valve timing, you'd simply
have a higher compression engine, but it would require higher octane fuel.

To put it another way Atkinson gives you better efficiency, but at the
expense of peak output.  Prius makes up for that loss in peak output by way
of the electric assist.


On Tue, Jul 8, 2014 at 6:18 PM, <pmdolan1 at sasktel.net> wrote:

> c'est vrai.
> On Tue, 8 Jul 2014 21:04:45 -0400 (EDT), DAN SNYDER <
> fancy_dancer at wideopenwest.com> wrote:
> The Atkinson cycle engine uses a delayed closing of the intake valve to
> reduce the amount of fuel/air mixture in the combustion chamber, thus
> reducing the temperature and the pressure of the charge at the end of the
> power stroke. It seems that a diesel wouldn't have to do that. The
> temperature and pressure at the end of the stroke can be controlled by the
> amount of fuel injected. n'est-ce pas?
>
>>
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