"Lloyd E. Sponenburgh" wrote:

Help me out here, guys.

The last diesels I ever worked on (and still do with my Deutz tractor and
John Deere mower) have an injector pump and solid injectors -- one per
cylinder; no moving parts except the poppet valve in each injector, and
the pump itself.

What y'all are talking about in this thread is an engine with
electrically-driven unit-injectors, but no description of the fuel
pressurization system, and no ideas about how one gets the 600-1000psi
necessary to pump the fuel and atomize it into the cylinder.

I guess I missed a decade or two with diesels; I didn't know that there
were electronic unit-injector diesels.

So... Help me out. How about some nice fleshy descriptions of what's
going on?

LLoyd

The new diesels are fancier than that.

The Ford / International 6.4 (which I'm most familiar with since I have
one) has a high pressure fuel pump that pressurizes the common fuel rail
to ~26,000 PSI (no, that is not a typo). There is a fuel cooling system
with it's own pump and radiator to keep the fuel temps from getting too
high. The injectors have piezo-electric actuators moving the partially
pressure balanced valve. The injectors may fire more than once during a
cylinders combustion cycle.

This engine also uses a dual sequential turbo setup with a small high
pressure turbo with servo driven variable geometry backed by a larger
conventional low pressure turbo. The small turbo spins up fast for
off-idle response and the large turbo catches up a second or two later.