LAS VEGAS (September 24, 2012) -

Cummins Inc. (NYSE: CMI) revealed today at MINExpo the next-generation QSK50 engine ready to meet EPA Tier 4 Final ultra-low emissions standards  with up to 2000 hp (1491 kW) output for powering large mining haul trucks, excavators and loaders. The 16-cylinder, 50-liter engine utilizes a fully integrated Cummins Selective Catalytic Reduction (SCR) aftertreatment system, designed as a drop-in replacement for the exhaust silencers. 

The SCR system, together with clean-combustion enhancements to the engine, enable the QSK50 to lower operating costs by 5 percent or more, due to significantly higher fuel efficiency and low levels of Diesel Exhaust Fluid (DEF) consumption.

Durability improvements on the engine, and the lower fuel burn, contribute to an extended life-to-overhaul for the Tier 4 Final QSK50, surpassing that of the best-in-class Tier 2 engine. Operators can expect an additional 1500 hours or more before rebuild, making a valuable contribution to reducing total life-cycle costs. Oil and filter services are extended to 500-hour intervals for Tier 4 Final, enabling the QSK50 to increase uptime availability levels for equipment.       

“Our 19-liter-to-95-liter QSK engine range will utilize SCR technology to not only achieve Tier 4 Final emissions, but to meet our design goals of improving in-service dependability and lowering the cost of operation so that mining operators achieve the lowest possible cost per ton,” said Jim Trueblood, Vice-President – Cummins High-Horsepower Engineering.

“SCR exhaust aftertreatment may be new to the mining industry, but it is not new to Cummins. Our experience with SCR is unrivaled in the industry and we have successfully applied it to over 400,000 Cummins engines since 2006. SCR technology is easily scalable and adaptable to our high-horsepower engine architecture, reflected in the very impressive results we are seeing from our QSK Tier 4 Final field test program,” added Trueblood.                                                       

The next-generation QSK50 meets the very low levels of 0.04 g/kW-hr particulate matter (PM) and 3.5 g/kW-hr for oxides of nitrogen (NOx) emissions required to meet U.S. Environmental Protection Agency Tier 4 Final regulations taking effect Jan. 1, 2016, in North America for engines over 751 hp (560 kW). 

The QSK50 achieves Tier 4 Final emissions standards without any compromise made to  power output or reliability, as the main focus of emissions reduction takes place in the exhaust stream, with the SCR aftertreatment removing NOx. This leaves the in-cylinder combustion able  to work more easily by focusing only on PM reduction. As a result, in-cylinder temperatures and pressure remain very similar to those of the Tier 2 engine – an important influence on power-cylinder durability. 

Taking this simpler approach to meet Tier 4 Final emissions standards means that the QSK50 and other engines in the QSK Tier 4 Final range avoid the need for any additional on-engine systems, any extra cooling or turbocharging complexity. From an installation perspective, this provides the advantage of retaining an engine envelope nearly identical to that of the Tier 2 predecessor. The Cummins SCR system also brings the benefit of a space claim the same as that of the typical Tier 2 exhaust silencers, providing equivalent acoustic reduction.

Cleaner Engine Credentials.
In terms of cleaner engine credentials, the QSK50 will set a new standard for high-output engines in the mining industry. The goal of a leak-free engine is achieved with superior seals on critical joints and a maintenance-free crankcase breather system, eliminating oil drips and mist.     

The engine fuel filters feature the latest NanoNet™ filtration media, patented by Cummins, enhancing fuel cleanliness and providing exceptionally high levels of protection for the high-pressure Modular Common Rail Fuel System (MCRS). 

The MCRS is upgraded for the Tier 4 Final engine, with operational improvements based on a huge number of accumulated-hours’ experience with the Tier 2 engines. Power and torque delivery are exceptionally fast and smooth, reaching a peak torque of 5805 lb-ft (7871 N•m). Fueling is finely balanced across the cylinders, providing low levels of vibration and ensuring that visible smoke from the engine exhaust is virtually eliminated. 

While Tier 4 Final regulations are focused on reducing PM and NOx emissions, mine site operators are increasingly looking for opportunities to reduce the carbon footprint of their equipment – and in this respect the QSK50 can make a major impact. The higher fuel efficiency of the Tier 4 Final engine brings a corresponding reduction in carbon dioxide (CO2) emissions compared with older engines. Even more CO2 savings can be realized by running the QSK50 on B20 biodiesel blend.     

About Cummins Inc. 
Cummins Inc., a global power leader, is a corporation of complementary business units that design, manufacture, distribute and service engines and related technologies, including fuel systems, controls, air handling, filtration, emission solutions and electrical power generation systems. Headquartered in Columbus, Indiana (USA), Cummins employs approximately 44,000 people worldwide and serves customers in approximately 190 countries and territories through a network of more than 600 company-owned and independent distributor locations. Cummins earned $1.85 billion on sales of $18.0 billion in 2011. Press releases can be found on the Web at or Follow Cummins on Twitter at and on YouTube at