atomization enhancement

[Roy]

> Hi all

  The Bosch single rail system being introduced   on
diesels uses a mechanical pump to generate a     fuel
rail pressure of around 1800 bar.  The injectors   are
triggered like petrol injection injectors by a  
signal from the ECU.

--- Greg Hermann <bearbvd at sni.net> wrote:
> >A "puddle" of fuel in this context can mean a cloud
> of droplets in the port.
> >The shock wave that hits this breaks up the drops
> into smaller ones.  Sure
> >it gets diluted, etc. but its the best we have for
> now and it does work
> >pretty well.  The only way to inject atomized fuel
> in a short period of time
> >is with a mechanical injection pump except maybe
> the stuff used in single
> >rail diesels.
> 
> Or with an air boost.
> 
>  Does anyone know what the single rail diesels use
> for
> >pressure and injectors?
> 
> The injectors are directly above the chambers, and
> are actuated by an extra
> cam lobe/rocker arm. No idea what the pressure in
> the injector itself goes
> up to when it gets actuated--but HIGH--Probably
> hydraulic tappet style
> pressures. On a Cummins PT system (Pressure/Time)
> the fuel rail pressure
> varies with engine speed/ load, as this pressure is
> what determines how
> full the injectors get before getting activated by
> the cam. Up to maybe 300
> psi in the rail. Changing the "button" in the
> Cummins fuel pump changes the
> pressure /speed output curve of the pump, and thus
> changes the amount of
> fuel injected at full load on a Cummins. (Not all
> Cummins B series
> (pick-up) engines have PT injection. This is 855,
> KT, and triple nickel
> stuff.)
> 
> On Jimmys, there is a rack the length of the head
> which varies injector
> stroke, (adjusting the lash on the injector rockers
> and adjusting to
> equalize the strokes of the injectors is the source
> of the term "running
> the rack" or "running the overhead") and the fuel
> rail in the head is at
> relatively constant pressure, maybe 150 psi??
> But--again, the actual
> injection pressure is on up there.
> 
> Regards, Greg
> 
> 
> 
> 
> 

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