Twin vortex combustion goes live with JCB – and hopeful for trucks

The engine is being dubbed "the world's cleanest off-highway engine", and Ricardo says the technology behind it was designed to eliminate exhaust after-treatment, while also providing a robust and high fuel economy solution for mid-range off-highway vehicles. Interesting, though, Ricardo is currently exploring the potential to extend its clean combustion technology to larger engine sizes and believes it could provide a useful way forward for on-highway engines. Ricardo global diesel product group director Ian Penny explains that the system incorporates a patent-pending re-entrant combustion bowl design and injector nozzle geometry, which are combined with cooled EGR (exhaust gas recirculation), high air-fuel ratio and injector pressures, and closed-loop control, using electrical actuators for the exhaust and air handling systems. The mere fact that it is capable of meeting Tier 4 interim/Stage 3B legislation without typically bulky and expensive exhaust gas after-treatment gives it clear advantages in terms of fuel consumption, lower total cost, improved reliability and greater package flexibility. "The Ricardo [technology] provides a breakthrough in clean off-highway power, as demonstrated by JCB, with the announcement of its Ecomax T4 engine," says Penny. "We are continuing active development of Ricardo's twin vortex combustion system and hope that it will ultimately be able to deliver a solution for Tier 4 final regulations [that will apply from 2014] without the need for any form of after-treatment," he adds. "Meeting Tier 4 emissions legislation is a massive challenge but also a huge opportunity for innovation – an opportunity to come up with a solution that has real advantages for our customers. We believe the result is not only the off-highway sector's cleanest engine, but a first for our industry," comments Alan Tolley, JCB's director of engine programmes.