2025 Ram trucks

[Renze]

The other great thing about in-line six configurations is they are cheaper to build/buy & maintain.

Inline engines do require a simpler block boring line, with only one row of cylinders.

They get better fuel economy

The examples you know best, might get, but thats not Newtons law. A lot of design factors are involved. Many heavy industrial engines are V configurations.

Their crankshaft is stronger because its supported by more bearings

In a V engine, the same crankpin never gets loaded at the same time by two cylinders. When the left bank cylinder makes compression and power stroke, with maximum piston pressure, the right bank cylinder is making intake and exhaust stroke, where the crank pin only accelerates and decelerates the piston at TDC and BDC.
The spacing between the main bearings usually doesnt differ from an inline configuration (Cummins KTA19 inline 6 and KTA38 V12) they are just staggered the width of a connecting rod bearing...

What matters is if the designers can put enough bearing surface in a given space to get to the required PSI of bearing load.
Cat doesnt seem to have an issue achieving that with the 3516 V16 engine found in their biggest mining equipment..

 

[sd455dan]

And thats a good thing. Reduces wear & fuel consumption.

Let’s roll back to the 2025 ram, shall we?

No more CP3? "New version" CP4... I certainly Hope so, especially when the trucks are out of warranty.

Why?? Maybe it is Not really a CP4 some sources are saying a completely different CP8? new design pump?

Not sure Glow plugs are better than a grid heater either, more failure points.

 

[Hay Dude]

Inline engines do require a simpler block boring line, with only one row of cylinders.

The examples you know best, might get, but thats not Newtons law. A lot of design factors are involved. Many heavy industrial engines are V configurations.

In a V engine, the same crankpin never gets loaded at the same time by two cylinders. When the left bank cylinder makes compression and power stroke, with maximum piston pressure, the right bank cylinder is making intake and exhaust stroke, where the crank pin only accelerates and decelerates the piston at TDC and BDC.
The spacing between the main bearings usually doesnt differ from an inline configuration (Cummins KTA19 inline 6 and KTA38 V12) they are just staggered the width of a connecting rod bearing...

What matters is if the designers can put enough bearing surface in a given space to get to the required PSI of bearing load.
Cat doesnt seem to have an issue achieving that with the 3516 V16 engine found in their biggest mining equipment..

Since all of us basically run smaller OTR trucks and tractors, why don’t we keep the diesel engines limited to 25-500HP and under 15L in size?

We all know battleships and tugboats and huge mining equipment can have V configuration diesels, but perhaps we keep it to the other 99.5% of the equipment TBN’ers own/operate?

Just keeps the conversation practical and more useful to this group here.

The V-8s and in line six engines on TBN generally run 25-500HP and under 15L in size. Agree????

 

[DarkBlack]

Most important reason that the common idea is that long stroke means more low end torque, is because in naturally aspirated, 2 valves per cylinder engines, the valve diameter limits high rpm breathing on an undersquare engine vs an equal capacity oversquare engine, just because you can put larger diameter valves in a head atop a larger bore engine.

Glass half empty, or full?
What you are describing is a cause of an under-square engine having low torque at higher rpm’s (hp) , not a cause of higher torque at low rpm’s.
For a given engine displacement, the long crank throw’s mechanical leverage , is what directly gives a longer piston stroke its inherent ability of higher rotational torque.

 

[Hay Dude]

You have one mode...

Well, no. Not necessarily. Up until 2023, I had (2) Powerstroke V8’s.
So no, actually not one mode…..

I can speak about both. I also owned a dozen other Powerstroke V-8’s and 1 duramax V-8.
In line six pulls harder with less RPM. That makes it a better pulling/towing truck.
And it gets better fuel economy while doing so.

 

[Renze]

Glass half empty, or full?
What you are describing is a cause of an under-square engine having low torque at higher rpm’s (hp) , not a cause of higher torque at low rpm’s.

In general, Industrial diesels are advertised as having good torque backup, which means how much the torque increases when rpms drop. Torque backup percentage is always relative to the torque it makes at nominal rpm. So i stuck to the industry standard of relating peak torque to the max torque at nominal rpm. Engines like the European IH DT402 were praised for their low end torque, while the restrictive head on this 100x140mm engine just acted as a turbo wastegate before a wastegate became commonplace.

For a given engine displacement, the long crank throw’s mechanical leverage , is what directly gives a longer piston stroke its inherent ability of higher rotational torque.

Contrary to popular belief, the smaller piston surface on which combustion pressure is excerted, fully cancels out that extra mechanical leverage. Its all about how much valve you can stuff above a certain bore size.
Off course cam timing and turbocharging make a far greater difference in this day and age, but in the 80s it was all about valve and intake tract size.

A slightly oversquare engine does hold the better cards when designing for thermal efficiency, because of the increase in combustion room surface when the piston gets bigger. The highest temperatures occur in the top quarter of stroke, and diminishing the piston and head surface exposed to it, reduce thermal loss and increase efficiency... adding a millimeter of piston to head clearance gives far less heat absorbing surface than if the same volume of compression volume is created with 10mm more bore...

 

[Hay Dude]

When it comes to the “big 3” diesels (Powerstroke, Cummins, or duramax/Isuzu) in US pickups, I’d give Cummins the nod for a much greater capability and world renowned reputation as one of the top diesel engine manufacturers in the world. Isuzu is very good, too.
The vast majority of their designs are in-line.

 

[Renze]

In line six pulls harder with less RPM. That makes it a better pulling/towing truck.
And it gets better fuel economy while doing so.

Lower rpm means lower friction losses. Piston rings are the main cause of friction losses in an engine. Thats why the NT855 obsoleted the V903 in the 70s... it just had the better cards for cruising fuel efficient at low rpm on the interstate. When you dont have to use a fast camshaft to get peak hp at 2800rpm without a turbo, you can use a cam timing for torque and fuel efficiency at lower rpm cruising speeds and increase power density with a turbo (which also spools up easier with a cam designed for low end torque)

 

[Renze]

Not sure Glow plugs are better than a grid heater either, more failure points.

Have had diesels in my cars for 22 years. Never had a glow plug break, nor heard of a glow plug dropping into the cylinder.

I do hear Gale Banks talk about ruining an engine when the grid heater bolt rots off and destroys a piston... i never heard of any other engine with this failure point, ever..

 

[DarkBlack]

Contrary to popular belief, the smaller piston surface on which combustion pressure is excerted, fully cancels out that extra mechanical leverage. Its all about how much valve you can stuff above a certain bore size.

It’s not just “a popular belief “ , it’s a Physics fact.
Your “Smaller piston fully cancels out the extra mechanical leverage “ ..No idea where you came up with that one, but if one was to believe it at face value, then there’s no torque advantage to design a longer stroke engine.

Large valve size isn’t a big factor until you’re higher in rpm’s, or under high turbo pressures