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pletely integrated engine builder—capable of designing and manufacturing a com- plete diesel power platform in-house— Cummins refined its emissions-control solution so that its Tier 4 Interim mid-range and heavy-duty engines were "pre- designed" to meet the additional demands of Tier 4 Final standards without signifi- cant changes. It leveraged its over-the-road technology platforms to develop products that were validated for the off-road market. The Tier 4 Final architecture for both its mid-range engines—which include the QSB 3.3, QSB 4.5, QSB 6.7 and QSL 9, offering power ratings from 75 to 400 hp— and its offroad heavy-duty engine range (QSX 11.9 and QSX15, with power ratings from 350 to 675 hp) include Cooled EGR, plus SCR. In the mid-range engine group, SCR employs the Cummins Compact Catalyst (CCC), while the larger engine group uses a Cummins particulate filter. Citing, as an example, the performance specifications of Cummins' QSB 6.7 engine after the Tier 4 Interim to Tier 4 Final transition, Sterling let the facts speak for themselves: "Same power output and performance, reduced fuel consumption and no change to engine installation." In addition, the Tier 4 Final QSB 6.7 brought no changes to engine oil drain intervals, or to fuel, oil and coolant filters. The Tier 4 Final version includes a no- maintenance design crankcase breather and a DEF pump filter that shouldn't require replacement before about 3,000 hours of operation. The "easy install, easy maintenance, no performance loss" is a recurrent theme shared by the major diesel builders, aimed at assuring equipment OEMs and operators that Tier 4 Final engines won't pose unex- pected usability problems. Cummins called attention to its Tier 4 Final field-test program earlier this year, stating that the program had accumulated more than 140,000 hours with operators working in commercial service. The field- test program, initiated two years ago, includes nearly 70 different machines at sites selected specifically to cover chal- lenging conditions. Cummins noted that the field-test pro- gram went beyond typical wheel-loader and excavator endurance test cycles to cover a wide variety of specialized equipment, such as a rock drill working at a mine site in very dusty, abrasive conditions. Initially focused on the QSB6.7, QSL9 and QSX15 6-cylinder engine range across the 174 hp to 675 hp (130-503 kW) power range, the field-test program then expanded to incorporate the new heavy- duty QSG12 and compact QSF2.8. The company said field-testing of its QSK high- horsepower engine range for mining is well advanced, including the QSK19 engine rated at 800 hp (597 kW). Cat Solves its Myriad Applications Puzzle Caterpillar, which claims pole position as the largest vertically integrated manufactur- er, had to find a way to deliver engine solu- tions that not only met increasingly strin- gent emissions standards but also the per- formance criteria of each specific customer. With an engine product line that ranges in power output from 4.1 kW (5.5 bhp) to more than 5,587 kW (7,500 bhp), that posed a unique challenge, according to the company. The number of specific customer applications using Cat engines today easily reaches into the thousands. Cat said its Tier 4 Final technology choic- es provide the ability to reliably manage aftertreatment thermal needs, minimize product content changes, and in most cases, require only one supplemental system compared with Tier 4 Interim. Additionally, Caterpillar's experience DPF technology and the decision to utilize it on many engine platforms positions Cat engine systems to meet future particle count stan- dards should they be implemented. By working closely with its customers to understand their business and equipment requirements, Cat said it determined that one technology solution does not fit all applications; its Tier 4 architecture— encompassing multiple combinations of electronics, fuel systems, air systems and aftertreatment components—based on engine size, application and geographic destination results in scalable, integrated systems that can be tailored to meet cus- tomer needs. Mike Reinhart, Caterpillar's Industrial regional marketing manager, explained that Cat determined that a DPF-based after- treatment solution provided maximum cus- tomer value at Tier 4 for its engines in the 130 kW (175 bhp) to 560 kW (750 bhp) range—generally offering better transient response, greater power density and reduced fuel and total fluid consumption. The DPF solution, according to the compa- ny, was proven at the Tier 4 Interim phase with more than 40 million operating hours recorded by customers on more than 80,000 engines powering Cat machines and OEM equipment. For certain applications requiring engines rated 129 kW (173 bhp) and below, it developed select no-DPF systems. Elimination of the DPF on these engine platforms allows for easier, more flexible installations into limited spaces. Con- versely, larger equipment in the 130 kW (175 bhp) to 560 kW (750 bhp) range provide more installation space and the capability to introduce modular after- treatment solutions. Cat has developed a DPF to work with its Ventilation Reduction (VR) Package available on Cat LHD's and underground mine trucks. VR Package engines have a lower level of diesel particulate matter (DPM) in their exhaust compared with EPA Tier 3 engines. Due to local mining regula- tions, the VR Package is not available in every region. The Cat DPF uses flow-through filter technology and catalytic conversion to lower DPM to an even lower level than with the VR engine alone. The DPF is installed in place of the existing muffler/DOC package. The filter medium is optimized to work with the VR Package engine hardware and software to deliver more than 50% DPM reduction in the exhaust. There is no increase of NO x compared with muffler/ DOC system, and the system maintains engine back pressure within specifications. According to the company, the DPF will not plug with particulates and ash, and JULY 2014 • E&MJ; 39 www.e-mj.com D I E S E L E N G I N E S Cat Industrial, which sells the company's engines to equip- ment OEMs, said it will offer a range of Tier 4 Final-compli- ant models, including the C7.1 ACERT engine shown here up to the much larger C27 and C32, beginning later this year. EMJ_pg38-41_EMJ_pg38-41 7/2/14 3:26 PM Page 39