Darlington, UK (February 7, 2011) – Cummins will highlight the Stage IIIB/Tier 4 Interim QSB3.3 engine at Samoter, Verona (Mar 2-6) with a power increase taking the top rating to a new high of 90 kW (120 hp). The improved power curve will further add to the premium performance associated with the 4-cylinder, 3.3-litre engine and will enable enhanced productivity for compact equipment.

The QSB3.3 power increase was made possible due to more efficient combustion realised by the aftertreatment simplicity of the Cummins Compact Catalyst, specifically developed to meet Stage IIIB/Tier 4 Interim emissions taking effect January 1, 2012, for the 56 to 129 kW (75 to 173 hp) power range. The catalyst captured the attention of the industry when introduced as a fully passive and service-free aftertreatment.

The catalyst removes particulate matter by oxidation with simple exhaust flow-through operation. The remarkably small size of the QSB3.3 catalyst – less than 500 mm long – provides a major installation benefit.

The 90 kW Tier 4 Interim rating is one of the highest in the industry for an engine of this size, representing an 11 percent increase in power output above the current Tier 3 engine. This is significant for equipment manufacturers looking to increase power beyond today’s top rating of 82 kW (110 hp) – while retaining the space-saving benefit and fuel efficiency of a 3.3-litre installation.

“The Tier 3 QSB3.3 set a new power standard as the first off-highway engine of this size to incorporate a High Pressure Common Rail fuel system and full-authority electronic controls,” said Chris Calas, Cummins QSB3.3 Product Manager.

“For Stage IIIB, the QSB3.3 moves even further ahead of similar sized engines with the benefit of a fit-and-forget catalyst. The small catalyst will make a big difference for compact excavators, skid-steers, telehandlers, small cranes, air compressors and many others types of equipment typically used in rental fleets.”

“The QSB3.3 has earned an industry reputation for robustness while operating in the toughest applications for an engine of this size. For Stage IIIB, the engine builds on a proven platform to provide the same inherent level of durability,” added Calas.

The Cummins Compact Catalyst is matched in design simplicity with a cooled Exhaust Gas Recirculation (EGR) system incorporated on the QSB3.3 to reduce Oxides of Nitrogen. The EGR system is specifically scaled down from Cummins 6-cylinder platform to the compact 4-cylinder, and is driven by a single variable flow turbocharger.