At this year’s Intermat, Cummins is introducing its next-generation QSL9 engine platform, which it says will be ready to meet U.S. EPA Tier 4 Interim and EU Stage IIIB emissions regulations and do so with better performance and a lower cost of operation. Emphasis will be placed on the QSL9 as a fully integrated air-intake to exhaust aftertreatment system with all Tier 4 technology enablers designed and manufactured by Cummins.
All the Cummins engines being unveiled for Tier 4 benefit from the company's cross-industry experience.
“We have gained vast experience from the work that we’ve done in automotive and then recognizing unique challenges of the off-highway market,” said Ric Kleine, Vice President, Cummins Off-Highway Business. “By the time we get to production, we’re going to have significant hours in both on-road or in operational types of applications with equipment as well through field testing and our in-test cell.”
The 8.9-L Tier 4 platform incorporates a Cummins fuel-injection system that was co-developed with Scania several years ago for heavy-duty on-highway use. It enables multiple injection events with very high fuel-injection pressure across all engine rpm speeds, resulting in cleaner combustion and improved engine response. The common rail fuel system is complemented by a Cummins variable geometry turbocharger with a sliding-nozzle design, which continuously varies the airflow boost to precisely match engine rpm and load demands.
“The QSL9 offers significantly more power flexibility for Tier 4 applications,” said Kleine. “A peak power output up to 400 hp (298 kW) enables the QSL9 to power equipment usually associated with larger displacement engines. With QSL9 power ratings extending down to 240 hp (179 kW), this brings the durability and improved torque of an 8.9-L to equipment typically using lower displacement engines for Tier 3.”
Kleine says the QSL9 will be used as a base to replace the 8.3-L QSC, “offering an even more attractive power solution for equipment manufacturers. QSL9 ratings are broadened to take advantage of 8.9-L displacement benefits with higher performance and fuel economy for 2011 low emissions levels.”
The QSL9 uses the same Tier 4 emissions architecture as previously announced for the smaller QSB6.7 and larger QSX engine. An integrated Cummins Particulate Filter enables a 90% reduction in particulate matter, and a cooled exhaust gas recirculation system reduces NOx by 45%. The PF replaces the exhaust muffler with equivalent sound reduction and has a particularly rugged design hardened to withstand severe shock loads and vibration.
Air intake flow for the Tier 4 QSL9 features a high-performance Cummins Direct Flow Stage IIIB air filter by Fleetguard providing a 35% smaller installation profile than typical engine air filters, yet retaining the same filtration efficiency. This is accomplished by creating a direct flow path through the filter media which is packaged in a rectangular configuration rather than a conventional cylindrical shape.
“We’ve invested very heavily in a wide variety of technology areas, and we’re looking at really taking full advantage of that technology from air in to the exhaust out,” said Kleine. “That has enabled our engineering teams across the company to work very closely together in a collaborative fashion that enables them to really understand a lot more of the detail than you can get into with just a business relationship with an outside supply.”