Four-Cylinder Diesels Meet Tier 4 Interim Standards

The latest versions of its QSB3.3 and QSB4.5 engines in the 75–160 hp power range will meet 2012 EU Stage IIIB and U.S. EPA Tier 4 Interim off-highway emissions standards, according to Cummins. The new four-cylinder engines still retain 3.3 and 4.5 liter proven platforms and will be sold as a fully integrated air-intake-toexhaust system. The engines’ low emissions output is due to cooled Exhaust Gas Recirculation (EGR) for NOx control and exhaust after-treatment to remove particulate matter. According to Cummins, its High Pressure Common Rail fuel system can be employed to meet the Tier 4 Interim while the compact cooled EGR system and the after-treatment unit have been designed for these four-cylinder platforms specifically. In order to manage the EGR flow across the engine power range an upgraded turbocharger with electronic control will be used. The particulate after-treatment unit for the Tier 4 Interim QSB3.3 and QSB4.5 replaces the muffler in the exhaust stream; it removes more than 90% of particulate matter but still offers equal noise reduction. The after-treatment unit is small, can be installed horizontally or vertically, and meets the toughest vibration and shock loading requirements. The Direct Flow air filtration system provides a 35% smaller installation profile than radial air filters, yet supplies the same filtration efficiency, says Cummins.

As featured in Womp 09 Vol 05 -