The all new 6.7 liter Cummins Turbo Diesel meets the 1/1/2007 emissions regulations and produces 305 horsepower at 3,000 rpm and 610 lb-ft of torque at 1,600 rpm.
Unlike the existing European 6.7 liter Cummins which is a long stroke design and is a stroked 5.9L with a bore of 102mm same as with the existing 5.9. The 2007 Dodge engine has a bore of 107mm and a stroke of 124mm. To meet the new emissions regulations it uses cooled EGR along with a diesel particulate filter, an oxidation catalyst, a variable geometry turbo, and a new controlled sealed crankcase system. This engine is more complicated than the existing 5.9L design with many more sensors and a much larger ECM to monitor them with 10,000 parameters. For instance, the ECM has 10,000 parameters.
The turbo is a Holset variable geometry turbo that uses fixed vanes and a sliding plate to provide the variable geometry and is actuated by an electric valve which is a much simpler and more durable system then othe other Variable Geometry systems on the market. The center section of the turbo is now water cooled and with the variable geometry turbo it can now be used as an exhaust brake and the 6.7L is the first to come stock with an exhaust brake able to provide 35% more braking than the existing butterfly valve exhaust brakes. The switch for the exhaust brake is integrated below the heater and A/C controls in the same area as the sliding rear window control.
While this system is much more complicated than the existing high-pressure, common-rail engine it has been used by Cummins since 2002 with 300,000 engines currently on the road with over 30 billion miles traveled.
In the exhaust system there is a self cleaning diesel particulate filter (DPF), an oxidation catalyst, and a muffler. The muffler is not part of the emissions control system and can be removed without violating emissions compliance and thus changing the aftermarket name from Cat back to DPF Back Exhaust System. As a part of the DPF system the ECM monitors three temperature sensors and change in pressure to monitor the state of the filter. To self-clean the DPF system, it raises exhaust gas temperatures (within a window) by manipulating the air fuel ratio. This is done thru a number of methods - some of which include an injection of fuel to ignite inside the DPF, the variable geometry turbo, and an intake flap mounted just prior to the intake air horn. The emissions system is designed for a government certified 185,000 mile life and remain within the 2007 emissions specs.
12-30-2007, 08:46 PM
6.7L Cummins Turbo Diesel Basics
Linear Mode
