Cummins Inc. Columbus, Ind., Introduced the latest generation of four-cylinder QSB3.3 and QSB4.5 engines; the new QSX11.9 and QSX15 heavy-duty engine duo; and a Tier 4 website for equipment users, at Bauma this week.
Offering a simplified Tier 4 installation across a broad 75- to 160-hp power range, with an air-intake-to-exhaust aftertreatment system specifically designed for flexible machine integration, the 3.3-liter and 4.5-liter QSB engines may help compact equipment-buyers more easily meet low-emissions regulations in 2012.
The four-cylinder QSB engines operate as integrated Tier 4 emissions systems with Cummins Compact Catalyst exhaust aftertreatment. Introduced for EPA Tier 4 Interim and EU Stage IIIB off-highway applications, the catalyst removes particulate matter (PM) by simple, flow-through passive oxidation, according to the manufacturer. Smaller than other types of aftertreatment, the catalyst can be installed in space-constrained equipment mounted separately from the exhaust muffler or as part of a combined catalyst-and-muffler unit. With no impact on equipment operation, the catalyst offers a maintenance-free "fit and forget" solution, suited for the rental-equipment market.
Compared with Tier 3 applications, the QSB3.3 and QSB4.5 engines can achieve up to 5 percent improved fuel efficiency for Tier 4, depending on duty cycle, according to Cummins. Cleaner, more fuel-efficient combustion is achieved with a cooled Exhaust Gas Recirculation (EGR) system to reduce oxides of nitrogen (NOx) emissions. Extensively proven on Cummins six-cylinder engines, the EGR system is scaled down for the four-cylinder, and is driven by a variable-flow turbocharger.
"By focusing on design simplicity, the four-cylinder QSB engines reflect the need to maximize installation flexibility for Tier 4 compact equipment," said Hugh Foden, executive director, Cummins Off-Highway Business. "The Tier 3 QSB3.3 and QSB4.5 have earned an enviable reputation for durability and power productivity. Now, with the Cummins Compact Catalyst and upgraded performance systems, we are able to achieve low emissions without compromising the ability of these engines to perform at the highest load factors or in the toughest applications where they excel today.”
The new QSX11.9 and QSX15 heavy-duty engine duo, designed for the off-highway industry in the 300- to 600-hp range, features the Cummins Xtra-High Pressure Injection (XPI) fuel system and a variable geometry turbocharger. The 11.9-liter and 15-liter engines are supplied as fully integrated air-intake-to-exhaust aftertreatment systems to meet 2011 EPA Tier 4 Interim and EU Stage IIIB regulations. The engines use a Cummins particulate filter to reduce PM emissions by over 90 percent, according to the manufacturer, and incorporate an EGR system to reduce oxides of nitrogen emissions by 45 percent.
While achieving low emissions, the QSX engines will lower operating costs with up to 5 percent improved fuel efficiency compared with Tier 3, depending on duty cycle, states Cummins. Machine productivity is boosted beyond that of Tier 3 applications, with faster engine response and significantly higher torque rise. Cleaner and quieter operation is a further noticeable benefit.
"We are very excited to see the arrival of the 11.9-liter and 15-liter QSX engines for Tier 4, as they represent the leading edge of Cummins technical development," said Foden. "The QSX engines are the culmination of a heavy-duty engine development program with an investment by Cummins of almost $100 million. With the on-highway ISX version of the engine already on the road in North America, this means that the QSX engines will enter the off-highway market with proven performance.”
Cummins has also launched a Tier 4 website to provide equipment users with an early insight into the performance and operation of field test installations ahead of the January 2011 effect date for EPA Tier 4 Interim and EU Stage IIIB low emissions engines above 173-hp. Located at www.tier4.info, the website content is based on more than 40,000 hours of accumulated experience in Tier 4 powered equipment on customer field tests and evaluation tests by equipment manufacturers, according to Cummins.
"The clear message from our field test customers is that they prefer using equipment repowered with Cummins Tier 4 engines, compared with the equivalent Tier 3 engines they replaced," said Foden. "Field test equipment operating on commercial service has demonstrated improved engine response and lower fuel consumption, while achieving the same exceptional levels of uptime achieved by the Tier 3 installations.
The website will continue to be populated with additional information as Cummins rapidly approaches a significant milestone of 100 completed Tier 4 installations. The site is expected to provide a useful educational resource for OEM dealers, rental companies and equipment operators. Visitors can learn about the next generation technology, including details about Cummins’ exhaust aftertreatment and Direct Flow air cleaner.