o Ram 1500
by Gary S. Vasilash
> Editor-In-Chief
t Ram is heading the pack of lightduty pickup builders by ofering the
3.0-liter EcoDiesel V6 that provides
240 hp @ 3,600 rpm and 420 lb-ft
of torque @ 2,000 rpm.
Mike Cairns, chief engineer, Ram Truck,
breaks down the characteristics of the
turbo-diesel:
• The engine has a bedplate and
cylinder block of compacted graphite
iron, which provides strength,
durability, and provides good NVH
characteristics. The cylinder heads
are heat-treated aluminum. (Given
that the compression ratio is 16.5:1,
we wonder whether aluminum
heads are up to the task of dealing
with the compression combustion, so
we ask Jamie Standring, who heads
up Ram Powertrain Engineering,
who says that it can readily handle
it and that it has been now been
used in several diesel applications
for years.) The structural oil pan is
aluminum, as well.
• The crankshaft and connecting rods
are forged steel. Pistons: aluminum
alloy.
• The EcoDiesel uses Fiat's MultiJet II
common rail fuel-injection system.
It provides 2,000 bar (29,000 psi) of
line pressure. What's notable about
the MultiJet II system is that it allows
fuel-injection events to occur up to
eight times per cylinder cycle. What's
known as "injection rate shaping"—
modulating the interval between two
consecutive injections—helps minimize
noise from the injection event.
• To help address emissions (it meets
50-state emissions compliance for both
tier II and bin 5) there is an exhaust
gas recirculation (EGR) system that
deploys electric valves rather than the
more-conventional pneumatic type.
The selective catalytic reduction (SCR)
system uses a diesel exhaust fuid
system; the urea-based fuid is held
in an eight-gallon tank, a quantity
sufcient to handle, on average,
10,000 miles of driving.
• Hegbloom acknowledges that lightduty truck buyers typically have
a deep commitment to brand. But
because of the EcoDiesel, he says,
"This might allow us to bring in a
Ford or Chevy loyalist who never
considered us in the past."
It is the classic competitive advantage.
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