Originally Posted By: Rabbler
How is a rear driven cam any more emissions friendly than a front driven cam?
Is the new cummins 6.7 a rear drive cam?
Sound like a good way to complicate a relatively simple design.
Maybe the did it for noise reduction?
I know the Cummins and Duramax common rail diesels can suffer from objectionable noise due to cam/crank/injector pump backlash.
The location of the geartrain has nothing to do with emissions, in and of itself. But European diesels are generally quite a bit cleaner than their American counterparts, as (some) emissions laws over there are a few years ahead. As emissions regulations tighten on this side of the pond, several manufacturers are bringing over their European designs rather than re-inventing the wheel. Cabover trucks are the norm over there, hence rear geartrain engines are the norm. Rear geartrains are not ideal in conventianal American trucks from a serviceability standpoint... but they work fine until something breaks. So that's what we're stuck with.
And yes, the new Cummins 6.7 has the rear geartrain.