23 March 2010
JCB announced its new ‘Ecomax T4’ 4.4 liter engine—the first production engine to feature the Twin Vortex Combustion System technology which enabled meeting the Tier 4 interim (Tier 4i)/Stage IIIB emission standards in the mid-range off-highway engine without the need for any form of exhaust gas aftertreatment.
Development of the new combustion system was carried out by Ricardo in collaboration with JCB, who will be the first production user of the new Twin Vortex Combustion System technology.
The Twin Vortex Combustion System—as used in the Ecomax engine—incorporates a re-entrant combustion bowl design and injector nozzle geometry which are combined with cooled EGR, high air-fuel ratio and injector pressures, and closed-loop control strategies using electrical actuators for the exhaust and air handling systems. The system allows for the elimination of exhaust aftertreatment and—according to Ricardo—can reduce fuel consumption, but no fuel economy figures were provided.
The Twin Vortex Combustion System also provides an attractive development pathway for the Tier 4 final regulations, said Ricardo. To achieve this in its current form, it would require the addition of NOx aftertreatment such as an SCR system. Ricardo is continuing the development to ultimately meet Tier 4 final emission standards without the need for any form of aftertreatment. Ricardo is also exploring the potential to extend the combustion system to larger engine sizes and considers its application for on-highway engines.