The pilot injection/primary injection strategy has changed significantly. Formerly, a small pilot injection was followed by the larger injection event; at higher loads and above 2000 rpm, a single injection event would be used. In the new engine, two or three events are used. The pilot injection is larger, and when under power a post-event is added.
The engine control module now contains 550 kilobytes of code for engine control, while the previous 305 horsepower HO engine used only 350 kilobytes.
A new cylinder head has revised ports with less swirl.
High-cobalt stellite valve seats are used with high strength inconel valves.
Forged steel connecting rods with cracked-cap technology are carried over from the 305 horsepower engine.
Exhaust manifold material and shape has been slightly revised for durability, and multi-layer gaskets are used between the manifold and head.
Piston bowls are slightly more open.
Cooling passages for the piston rings are carried over from the 305 horsepower HO engine.
The turbocharger remains an HY-35, but with a new, larger compressor wheel and housing for increased air flow. The wastegate has an electronic controller to better match boost pressure to engine needs for optimized emissions control. The turbo shaft bearings have small oil reservoirs under them to improve oiling on cold start-up. The oil drain tube is flexible steel, replacing the former system of two rigid steel tubes connected by a hose with two worm-drive clamps.
Engine fan shroud is now engine mounted, with soft plastic seals to the radiator assembly.
Fan clutch calibration is different, to reduce fan roar and to improve cooling.
Intercooler is new, with higher flow. The end plates and hose connections are plastic.
The changes made to develop the 600 were more driven by emissions than as an increase in torque and hp. Dodge advertises it as a power thing but in reality, they added a third injection event to clean up emissions in leu of cooled egr.
A forum community dedicated to Chevrolet and GMC diesel truck owners and enthusiasts. Come join the discussion about duramax engines, performance, builds, modifications, classifieds, troubleshooting, maintenance, and more!