Ram HD 1000 lb-ft MPG loop

RoyJ wrote:

ShinerBock wrote:
Yes, at least from what I have seen in the dyno cells when I worked at Cummins. The crank and the internals can handle well over what the pick up truck puts out(I am talking hundreds, not tens) without any significant or even notable reduction in B10 and B50 life percentages. Have you seen otherwise in any of the engines you dyno tested when working for an engine manufacturer?

All anecdotal. In markets where there are no emissions, why don't Cummins or anyone offer a 500 kW stationary generator (say in Africa) powered by an ISB?

Anecdotal? How many engines have collected data showing that a 500 hp 6.7L in a marine application will have reduced B10 and B50 life percentages over a 200 hp 6.7L that goes into a medium duty truck? How much power did you run to know that breaking point of internals? I am going to guess a big fat zero, and if so then what are you basing your statements on?

RoyJ wrote:

ShinerBock wrote:
The first draw back is the turbo especially on the turbine side. It is a major bottleneck and causes temps to rise quickly along with high drive pressures which puts a strain on internals(and head gaskets). However, it was made to control emissions at all rpms like all stock VG turbos. It, like the rest of the hardware and tuning is made to meet emissions and therefore very conservative in regards to what it can actually handle.

Not sure what it has to do with durability.

If you actually tested any turbo diesel engine you would know what this has to do with durability and what drive pressure and high EGT's does to internals. The fact that you don't know speaks volumes.

A VG turbo creates high drive pressure along with thermal stress and is added solely for emissions purposes. This combined with bad timing spikes will blow gaskets and damage other internals. A correctly sized fixed geometry turbo will not only have considerably less drive pressure and produce a lot less heat, but it will make more power with less boost.

Just replacing the stock VGT with a correctly sized fixed geometry will allow you to create more power while reducing stress and heat on the engine internals. However, since these engines are designed and tuned to meet emissions, a VG turbo must be used even at the detriment of the engine.

Here is a good video by Gale Banks going over what I am talking about. It is on a new L5P Durmax, but the same concept still applies to the Cummins 6.7L since it uses a similar turbo setup. LINK

RoyJ wrote:

ShinerBock wrote:
Nope, it would not be reasonable at all. At least not with my 20+ years of experience in the medium/heavy duty industry working for various engine/truck manufacturers and dealership groups. How many years have you been the industry to come up with that theory?

I didn't ask for your credentials, and btw, are you a registered engineer or just the tech running the test bench? Why is it not reasonable to assume engines operating at lower power, which experiences lower mechanical and thermal stresses, to incur less warranty repairs?

I don't care if you didn't ask. I gave my credentials because it was obvious you did not have any.

EDIT: Correction, the marine engine 6.7L (which abides by less stricter emissions requirements and therefore uses a larger fixed geometry waste-gated turbo) is at 550 hp/1,250 lb-ft, not 500 hp like I stated above.