In the European commercial vehicle sector, Cummins has seen its fortunes decline in recent years. This has been due in part to consolidation in the European industry and the predominance of vertical integration, leaving fewer opportunities for specialist engine manufacturers.
Cummins’ new ISX11.9 11.9-L engine, however, would be a comfortable fit for European automotive use. Truck engine capacity in Europe averages around 12 to 13 L for long-haul use, around 2 to 3 L less than the average in North America. For North America, Cummins is targeting dump trucks, mixers, fire trucks, and refuse vehicles for the engine.
As with Detroit Diesel’s DD13, 15, and 16 (www.sae.org/mags/tbe/7220), the ISX11.9 uses Selective Catalytic Reduction (SCR) for U.S. EPA 2010 compliance. The system relies on the injection of aqueous urea into the exhaust gases upstream of the catalytic converter to reduce oxides of nitrogen to nitrogen and water. The engine succeeds Cummins 10.8-L ISM, which can trace its ancestry back beyond the L10 10-L engine, which was substantially redesigned to become the 1990s M11.
As the DD16 shares components and systems with the DD13 and DD15, the ISX11.9 shares a common architecture and many components with the 14.9-L ISX15. This includes the XPI common-rail system, cooled exhaust gas recirculation (EGR) componentry, electrically activated variable geometry turbocharger, electronic controls, and aftertreatment systems.
Cummins quotes injection pressures of up to 2413 bar (35,000 psi) from the XPI common-rail system, which made its debut on Cummins’ heavy-duty engine range for the first time in the new ISX engines. The new engine family also signals a switch from two camshafts to one. The earlier ISM and ISX engines, equipped with electronic unit injectors, operated the injectors with one camshaft and the valve gear with the second. The switch to common-rail injection for the heavy-duty engines removes the need for a camshaft to activate the injectors.
ISX11.9 power output ranges between 310 and 425 hp (231 and 317 kW), with maximum torque of between 1150 and 1650 lb·ft (1559 and 2237 N·m). The engine provides clutch engagement torque of 700 lb·ft (949 N·m).
The company gives a dry weight of 1175 kg (2590 lb) for the engine, with the aftertreatment system adding around 101 kg (223 lb).