Diesel Progress North American

SPECIAL REPORT

SOME FINAL WORDS
ON TIER 4 FINAL
Engine manufacturers outline technology paths intended to surmount
last — for now — significant emissions hurdle

What is (fill in the blank) going to do for Tier 4 final?” While we may have written extensively about it in Diesel Progress for the last five years, tweeted about it, given speeches about it, participated in panel discussions about it, no subject continues to draw interest quite like the implementation of Tier 4 final engine emissions standards. With three different horsepower bands facing final standards over the next three years, people just can’t seem to get enough information.They’re always looking for that last nugget of data that will presumably make them feel more comfortable about what will be powering their machines for years to come.

Because of the segmentation of
the power bands and the different
implementation dates for each, the
flow of information has been anything
but steady and consistent. At this writ-
ing, some engine manufacturers are
continuing to shape their messages
about their Tier 4 final strategies.
John Deere, for instance, has not
disclosed specifics on how they will
meet the standards publicly, but in a
statement told Diesel Progress that
“we can say that technologies such
as cooled EGR, variable geometry
turbochargers and exhaust filters will
likely be the foundation technologies
for meeting final Tier 4 regulations.”
Deere did say it will make its first
statement about Tier 4 final in early
March, with more to follow as the year
goes on.

Other manufacturers laid out their plans to the world earlier and others have all but said they may not even say much to their customers, but will more or less just say, “Here you go, they’re certified, enjoy.” Whatever works.

“
Being journalists, we at Diesel
Progress obviously like the forthcom-
ing approach and believe that the
more people know about what’s out
there and how it works, ultimately, the
better it is for all.

temperature regeneration to periodically burn away the particulate matter that collects in a diesel particulate filter (DPF). Cat said the regeneration process is transparent to the equipment operator and has no adverse effect on the machine’s duty cycle. Periodic cleaning of ash residue from the DPF is required, but typically only at 3000-hour intervals.

In addition, Cat said the design of the new engines controls heat rejection, meaning that cooling requirements will not consume valuable space within the constraints of a small machine’s overall layout.

CATERPILLAR

Three- and four-cylinder diesel engines, with displacements of 1. 5 and 2. 2 L, will lead the way for Caterpillar’s Tier 4 final for the 49 to 74 hp power band. First shown last year, the two engines — the C1.5 and the C2. 2 — provide ratings from 33 to 66 hp and build on the design features of their predecessors.

The base design of the two engines includes high fuel tolerance, B20 compatibility and single-side servicing, plus a range of options to meet individual OEM requirements, Cat said.

Cat’s C1.5 diesel utilizes a compact DPF to help it meet Tier 4 final emissions standards.

For the 1. 5 and 2. 2 L engines, the aftertreatment module will use high-

CUMMINS

Cummins said its ability to design, build and integrate its own exhaust aftertreatment technology was key to its midrange and heavy-duty engines’ ability to meet Tier 4 final standards while maintaining the same engine architecture and systems — including the Cummins variable geometry turbocharger (VGT) and exhaust gas recirculation (EGR) — as its Tier 4 interim engines.

The six-cylinder QSB6.7 and QSL9 engines (146 to 400 hp) utilize after-treatment combining the Cummins Compact Catalyst (CCC) with selective catalytic reduction (CCC-SCR), while the heavy-duty QSX12 and QSX15 engines combine the Cummins Particulate Filter with selective catalytic reduction (CPF-SCR).

Cummins high-horsepower engines above 755 hp will meet the Tier 4 final emissions by incorporating a next-generation SCR system. The modular SCR system is scalable for the complete QSK engine lineup from 19 to 95 L to ease integration and assembly by the equipment manufacturer, Cummins said.

The SCR system developed by Cummins for Tier 4 final incorporates a copper zeolite-based catalyst designed to operate more efficiently at lower temperatures and incorporates closed-loop control. A CCC