atomization enhancement

[Greg Hermann]

Scuse me--

Perhaps I misunderstood what was meant by a single rail system--the
Jimmy's--a mid 1930's design-- hardly had an ecu!

Greg


>> 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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