atomization enhancement

[Greg Hermann]

>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