DAF announces PACCAR MX-13 Euro VI engine
6 April 2012
DAF Trucks announced a Euro VI version of their diesel truck engine, the 6 cylinder, 12.9 liter PACCAR MX-13. The new engine uses common rail injection technology, as well as a variable geometry turbocharger and exhaust gas recirculation (EGR). The aftertreatment system includes urea-SCR and an active diesel particulate filter (DPF).
The new Euro VI PACCAR MX-13 engine will enter production in the beginning of 2013. It will be available with power outputs of 300 kW (410 hp), 340 kW (460 hp) and 375 kW (510 hp).
While based on the US EPA 2010 emission technology, the new PACCAR MX-13 features a number of changes, including newly designed engine block for better stiffness and integration. The overall size of the engine has been reduced to enable fitting in the European cab-over-engine vehicle designs.
Perhaps the most important novelty is the new common rail system—a change from the electronic unit pump (EUP) injection used in both the US 2010 and the Euro V versions of the engine. The common rail system allows high injection pressures of up to 250 MPa (which is comparable to the maximum injection pressure in the EUP system), with the capability to use pre- and post-injections. Two high pressure common rail pumps integrated into the engine block are actuated by the same camshaft that drives the valves. Some of the plumbing has been cast into the cylinder block and head as well. The fuel in the central pipe is supplied using “smart dosing” controls, to increase efficiency and reduce hydrAulic losses by only compressing the amount of fuel that is needed.
The DPF system has been designed to maximize passive regeneration. For instance, the exhaust manifold and some other parts of the exhaust system have been encapsulated. When the exhaust temperature is too low, the engine switches to active regeneration. A seventh injector, positioned between the turbo and the DPF, injects fuel upstream of an oxidation catalytic converter in order to generate the heat.
The SCR catalyst, thanks to its “innovative coating”, is able to achieve maximum effect across a wider range of temperatures, said DAF. This suggests a zeolite-based catalyst, in contrast to the vanadium formulations that were common in Euro IV/V SCR systems. Engine manufacturers have avoided using vanadium catalysts in systems where SCR is coupled with particulate filters, due to concerns with vanadium volatilization during high temperature DPF regeneration events.
The US 2010 version of the 12.9 liter PACCAR MX engine has been used in a quarter of the Kenworth and Peterbilt trucks supplied in the United States since summer 2010, according to DAF.
Source: DAF