Anyresemblance etween 2
the 2007engineshownhereis strictly intentional,as the
companyannouncedthat its 2010engineswill meet the
the additionof NOxaftertreatment,
DOWN A FAMILIAR engines will use more of the same
technologies it employed in 2002 and
2007 - again with some refinements
ROAD FOR 2010 and some use of banked emissions
credits - and significantly, would not
Cummins' o-SCRstrategyfor 2010heavy-duty enginesbasedmostlyon require the addition of SCR.
According to Dr. Steve Charlton,
evolution existingtechnologies; CRtabbedfor midrangeapplications
Cummins executive director of Heavy-
Duty Engineering, the 2010 ISX will
be "an evolution of the '07 engine,"
BYMIKEBREZONICK that "will look and feel the same as
f there is one word that describes Cummins' response was based on what's there today.
Cummins' approach to engine de- essentially the same fundamental "We feel we have the key technolo-
velopment, it would probably be technologies, with some tweaks and gies in place to deliver product in 2010
"consistent." And nowhere has that the addition of affertreatment. that will satisfy customer requirements
consistency been more apparent than Yet the EPA's 2010 standards, which and will not neetJ NOx aftertreatment.
in the case of the Columbus, Ind., require yet another significant emis- There will be, in terms of overall engine
company's heavy-duty on-highway sions reduction, was an entirely differ- architecture, very little change."
engine products. ent situation. It was accepted by most That announcement flew in the face
As far back as 2001, Cummins in the industry that the path to 2010 of what had been the conventional
established a strategy founded prima- compliance lay in selective catalyttc wisdom surrounding 2010: that once
rily on a series of bedrock technolo- reduction (SCR), a form of NOx after- again, vehicle manufacturers and oper-
gies - cooled exhaust gas recircula- treatment that has been embraced by a ators would have to accommodate an
tion (EGR), high-pressure fuel injec- number of engine and vehicle manu- additional layer of aftertreatment in the
tion and advanced air handling - that facturers and is widely used in Europe. form of SCR. Along with the additional
carried it over the 2002/2004 EPA Once again, however, consistency expense and ~omplexity of SCR, many
emissions hurdles. When EPA stan- has reigned for Cummins. The com- in the industry had raised concerns
dards took another leap in 2007, pany has announced that its 2010 ISX continuedon page 60
DIESELPROGRESS AMERICAN 2
30 seconds. They get fuel, raise the
hood and check fluids, and they get
that truck turned around and out of
there. An extra stop for urea is unwant-
ed. And if you're going from Quebec to
Cummins'2010 heavy-dutyon-high- San Diego via Seattle, that's a long
wayengineswill incorporate new
the route to be looking for urea.
XPIhigh-pressure commonrail fuel system "On midrange, it's a whole different
developedaspartof Cummins' joint fuelsys- ball of wax. There, the mileages are
temsventurewith European enginemanufac- lower, the power levels are lower, the
turerScania. hatsystem, hichis alsobeing
T w urea consumption is lower and the
usedby Scania its Euro5engineplatform,is
in urea intervals are much longer. So in
designedto providefuel injectionpressuresin midrange, SCR is the right technology.
excessof 32,000psi, along with very precise We don't feel it's the right approach for
"The approach we're taking is
over the availability and supply of urea for heavy-duty Class 8 trucks. "We let bringing everything together - the
(used in SCR systems as a reductant), customer needs drive our technology, capability of XPI, combustion technol-
along with the requirement for the urea we don't let emissions drive our tech- ogy, controls, air handling - all of
levels to be monitored and maintained nology," said Charlton. "When we those are key."
by vehicle operators. choose technology, we use the cus- The most obvious enhancement to
While Cummins has made it clear tomer needs to drive the technical pro- the 2010 engines will be XPI, the new
that SCR has a role to play in the over- file that our engineers use to develop common rail fuel system developed as
all engine emissions toolbox -more their engines. part of Cummins' joint fuel systems ven-
on that later - the company simply "If you've been to some of the big ture with European engine manufactur-
didn't think it was the right technology fleets, you see trucks coming in every er Scania. That system, which is also
being used by Scania in its Euro 5
engine platform (see March-April 2007,
Diesel Progress International Edition),
Will replace the unit injection system
used on current products and is de-
signed to provide fuel injection pres-
sures in excess of32,000 psi (Cummins
did not disclose the exact value) along
with very precise metering capability.
"The XPI system gives us multi-
pulse capability," Charlton noted. "In
previous cases, it has demonstrated
up to five pulses, with a pre-injection,
a pilot injection, a main injection, a
post injection and a late post injection.
The very high pressure also allows us
to control particulates in the presence
of very high rates of EGR."
The performance of the EGR sys-
tem is critical in the Cummins strate-
gy. It has long been known that one
way to meet the more stringent 2010
standards would be to basically do
what worked for 2007, but just do
more of it - more EGR, higher turbo
continuedon page 62
deliver the airflow and performance, it
helps us deliver and control EGR, it
helps us increase the braking effec-
tiveness of compression brakes and it
helps us regenerate aftertreatment.
It's truly a flexible tool that we take full
advantage of in this engine."
The EGR system is a high-pressure
loop in which exhaust gas is taken
from before the VGT's turbine section
and returned to the engine after the
compression stage, "really, no change
from how we did it in 2002," Charlton
said. 'The whole idea is to control in-
take oxygen. With cooled EGR, we're
recycling exhaust products that are
depleted of oxygen. We put them
back into the cylinder and that's how
our oxygen is reduced."
What's changed dramatically is the
rate of EGR, he said. "We were at
15% EGR rate in the 2002-2004 time-
frame, and we got about a 50%
reduction in NOx," Charlton said. "In
2007, we applied approximately 25%
cooled EGR - it gave us another
50% reduction in NOx.
boost pressures, higher fuel injection company said provides optimized "In 2010, we intend to continue
pressures, etc. - what some have boost and EGR rates at virtually all down that path. We continue to reduce
dubbed "super EGR." operating conditions. oxygen content with cooled EGR and
Yet it was generally understood that "I once described the VGT as the achieve lower and lower tailpipe NOx
while those strategies would work in Swiss Army Knife of engine design until we meet the 2010 standards.
an emissions sense, they would fall and it really is," Charlton said. "It helps continuedon page 64
flat in terms of real-world operations.
It was thought that such an approach
would lead to fuel economy penalties
that would simply be unacceptable to
truck fleets and owner-operators
whose livelihoods can be determined Anotherenabling technology
for the Cummins2010en-
by fractions of an mpg.
Here is where Cummins' announce- gines is the Holset VG '
Turbo from Cummins
ment assumed its "what did they
say?" quotient, as the company said
that its 2010 engines would offer the
same horsepower, torque and most
cally actuated sliding-
importantly, fuel economy ratings as
nozzle design that the
its 2007 products, with no significant
company said provides'
impact on maintenance intervals.
optimized boost and EGR
And again, the EGR and air handling
ratesat virtually all operating
systems are Iynchpins of that capabili-
ty. The company will continue to use
the Holset VG Turbo from Cummins
Turbo Technologies that incorporates
an electronically controlled, electrically
actuated sliding-nozzle design that the
DIESELPROGRESS AMERICAN 2
"If all we did was grab exhaust gas, we had a reduction of 10 to 15% in about a 20:1 air/fuel ratio. The quality
cool it and put it in the cylinder, we'd airflow and took it from 28:1 to 24:1 of the gases being recycled is, from an
need very large displacement en- and the fuel system was the enabler emissions standpoint, higher and high-
gines, we'd need very high boost pres- of that. We improved fuel system er, as there's less oxygen in it. It's a vir-
sures, we'd need enormous peak capability - more pressure, more tuous circle that will reduce emission
cylinder pressures and we wouldn't controllability - which allowed us to and give us optimized fuel economy."
have a very realistic engine design. limit peak cylinder pressures, boost While Cummins will continue to use
"What we did was take air out of the pressures and heat rejection. the Cummins Particulate Filter, de-
engine. Back in 1998, we had approx- "For 2010, we're taking more air out signed and manufactured by Cummins
imatelya 28:1 air/fuel ratio. In '02/'04, of the engine than in 2007, down to Emission Solutions, as its primary
aftertreatment system, there will also
be an addition of a close-coupled cata-
lyst (CCC) mounted after the turbine
stage of the turbocharger. Similar in
concept to a unit used on Cummins
2008 Dodge Ram turbodiesel intro-
duced earlier this year (see February
VIBRATION PROBLEMS? 2007, Diese/ Progress) it is used to
HIGH TEMPERATURE maintain proper thermal levels at var-
ious operating conditions. In situa-
ENVIRONMENT? tions where higher temperatures are
needed, a small amount of fuel is in-
For compressors, pumps, generator jected into the exhaust stream through
sets and gas, natural gas or diesel a dosing tube. As it is chemically oxi-
dized by the CCC, it raises the tem-
perature of the exhaust stream and
ARCUSAFLEX@ FLYWHEEL COUPLINGS allows the downstream catalyst to
Torque ranges from 1,770 Ib-in to
1,673,000 Ib-in. "With lower NOxlevels, we had to
change our regeneration strategy,"
noted Charlton. "In order to get the
maximum temperature to the oxidation
process, we do 50% of the oxidation
close to the engine and the other 50%
happens where it happens today - in
the diesel oxidation catalyst at the front
of the Cummins Particulate Filter.
"It's really about getting the catalyst
light-off very quickly when we need to.
You can lose a lot of heat when you go
from the turbo to the aftertreatment. If
the aftertreatment is not on the back of
Highly flexible, torsionally
50ft couplings for universal the cab, you can have a 12 or 15 ft.
joint drive shafts. Torque run from the engine to the aftertreat-
ranges for VSK couplings
from 3,452 Ib-in to ment and it can cool down quite a bit.
424,836Ib-in. "Because the CCC is within 10 in. of
the turbine exit, we already have very
Many different styles and high temperatures, and periodically we
a large stoCKselection for
your specific needs\ will be able to put fuel into the exhaust
to maintain the proper temperatures.
RlNGFEDER We anticipate that it will not be a fre-
SOLE NORTH AMERICAN DISTRIBUTOR quent occurence in most cases."
www.ringfeder.com RFC As the final part of its 2010 strategy,
Cummins said it would expand its ISX
platform by adding two additional dis-
SEE DIRECTLINK @ WWW.DIESELPROGRESS.COM
64 DIESEL PROGRESS NORTH AMERICAN EDITION November 2007
placements to the existing 15 L enve- Cummins said that the initial build the same, along with the addition of
lope. New 11.9 Land 16 L displace- for the new heavy-duty engines will an ammonia slip catalyst at the back
ments will incorporate a common take place at its Jamestown, N.Y., of the system to reduce any issues
architecture, including the XPI fuel facility in the first quarter of 2008, and concerning ammonia emissions.
system, VG turbochargers, etc. test engines were expected to go into "SCR enables us to extend our
"We're excited to reveal that our service with selected customers power range while maintaining excel-
Heavy-Duty X platform will expand to around midyear. lent fuel economy, maintenance inter-
include three displacements, all fea- At the same time it eschewed SCR vals and overall low cost of owner-
turing a common architecture that in- for heavy-duty applications, Cummins ship," said Dave Crompton, vice pres-
cludes the XPI high-pressure com- also said that it would add that tech- ident and general manager, Cummins
mon rail fuel system," said Ed Pence, nology to its midrange on-highway MidRange Engine Business. "Lever-
vice president and general manager, engines for 2010. The logic behind aging our experience in Europe,
Cummins Heavy-Duty Engine Bus- that position lies in an understanding Cummins is positioned to implement
iness. 'This is the first time in nearly 20 of the different operating cycles of SCR better than any other engine man-
years that we've had common architec- heavy-duty trucks versus the myriad ufacturer in North America." ~
ture across our heavy-duty products." applications of midrange engines,
Pence added that the new 11.9 L which can be applied in trucks, buses To REQUEST MORE INFORMATION
ON THIS COMPANY
displacement "will supersede the ISM and specialty vehicles.
in North America. And once again, Cummins isn't
"The ISM will be retired in 2010 in really stretching its technology to do
the North American on-highway mar- it. The company has sold SCR sys-
ket," Pence said. "It will still be avail- tems in Europe for several years, and
able in all of our export markets and in 2006 it launched Euro 4 midrange
all of our off-highway market applica- engines with SCR for commercial
tions, which represents 45 to 50% of applications in Europe. The basic sys-
total M engine family production." tem for 201 0 midrange engines will be