New Cummins 6.7L Hits 1,000 lb-ft | Could it be Coming to a Ford Near You?
It was only a matter of time, Ram has become the first truck manufacturer to build a pickup truck to hit four-digits in the torque department. To be fair, about 98% of the credit for that achievement lies with Cummins. For 35 years Cummins has been cranking out the legendary B-Series engines, and for 2019 the 6.7L version has undergone a major update. It would basically be safe to call this engine completely new. While the overall design is basically the same, every major component has been upgraded. That includes; the block, the head, the pistons, the rods, the crank, the turbo, the cam, the lifters, the timing set, the fuel system, etc.
The engineers seemed particularly proud of this new timing set. Supposedly, it contributes greatly to overall NVH reduction.
This shot gives you a good look at the beefed up rotating assembly. Every part of it looks extremely stout.
Speaking of the compacted graphite iron engine block, that is the biggest piece of news from this engine. Not only is it a good deal lighter than the outgoing grey iron cast block, but it is also capable of containing much higher cylinder pressures. That feature was critical in the heavier fueling required to hit the 4-digit torque figure. Redesigning the block also allowed Cummins to move from the antiquated, but reliable, mechanical flat tappet lifters to hydraulic roller units. Gone are the days of having to occasionally pop off the valve cover to adjust the valve lash. A new camshaft design was also required, so the new unit is ground from a hollow steel billet, which is yet another place a little weight was shaved off.
The piston bowl looks to be de-lipped, so hopefully cracking won't be an issue.
The innards of the I-6 also received significant attention. A new heavier crankshaft was forged, and swinging from it will be beefier connecting rods (which still appear to be made of powdered metal) and upgraded cast pistons. The pistons feature and upgraded ring pack, an oil cooling galley, and a redesigned bowl. The wristpin is also much larger and heavier walled than the outgoing piece. The cylinder head is also a new casting, and special attention seems to have been paid to improving airflow and cooling capabilities. The engineers/marketing peeps I spoke with at NAIAS 2019 didn’t have much information to share about the actual changes made to the head, and it’s tough for the unfamiliar eye to pick them out without the old style one there for comparison.
I'm torn on the new lifters. More efficiency and less maintenance are big pluses, but it's hard to argue simplistic reliability of the old mechanical flat-tappets that were replaced.
The one area I was not thrilled to see change was the injection pump. Since moving to common-rail injection in 2003 the Cummins B-Series has utilized the Bosch CP3 pump. It is a rugged cast iron chunk that is tough and easily modded. For this newest generation Cummins has move to the Bosch CP4.2 pump found also on the 6.7L Powerstroke and 6.6L Duramax diesels. The 4.2 is more sophisticated and has an aluminum body. This leads to it being a bit more delicate than the CP3. With the general shit quality of diesel fuel found in most of the country, judicious use of fuel additives will be required if new Ram owners want to see a reasonable life out of their HPFP. Still, I have no doubt the aftermarket will have a CP3 swap kit available weeks after these engines start hitting the streets.
While the Bosch CP4.2 High Pressure Fuel Pump is more modern technology, I'm going to miss the outgoing CP3.
The rest of the changes are pretty much what you’d expect from any refresh/redesign. The water pump now has an aluminum body, the injectors are new, the turbo is bigger, etc. So what does all this mean for Ford owners? First, you can guarantee Powerstroke will jump to over 1,000 lb-ft of torque once the 10R140 transmission is introduced in the Super Duty. Most of the upgrades made to the Cummins are already baked into the 6.7L V8 PSD architecture. Second, there is also the possibility that we may see this new Cummins ISB find its way into the Medium-Duty Ford F-650/750 trucks. A red-painted ISB was the diesel of choice for many years in the big Fords going all the way back to the 12-Valve engine (which were grey/black) in the old F-800. When the Cummins marketing guys asked who I was shooting coverage for and I mentioned a Ford based publication, they said I should like some of their future applications. So that coy comment could mean something quite interesting, or nothing at all. We'll have to wait and see. At the end of the day, competition makes the breed stronger and I expect this new Cummins to be good for everyone.
Check out the new cast aluminum water pump housing.
Every part of the B-Series valvetrain is robust. Plus you no longer have to occasionally adjust the valve lash.
The new cylinder head is still cast iron, and the surface still looks properly thick.
Ignore that bead of weld from the cutaway process. Hardened exhaust valves and new injectors were also part of this update.