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Was contemplating a 2025 6.7 Cummins... Nope!

Brutal_HO said:
Never said it would prevent failure. However, it survived a destructive "killer" test far beyond the venerable CP3.

So what you're saying is RAM/Cummins is lying about the pump design? LOL.

"Ram/Cummins: The Bosch CP8 is a new fuel pump. The roller and shoe design that was in the old pump has been redesigned to a pinned roller-tappet architecture."​

Lastly, GM hasn't used the CP4 for forever, they've been running a Denso pump.



Familiar, but also not the same.
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Like I said.... It all sounds fantastic on paper and in the videos. Really does. And there is a great chance the "CP8" is God's gift to HPFP's and all of the CP4's ****ty history is now behind us.

Being a Ram guy for over 20 years and having owned at least 4 HD Rams... I sure hope it lives up to the hype.
 
mbarber84 said:
If the plungers are redesigned so that they are pinned, and unable to rotate axially in their bores, and the pump uses an independent lubrication circuit to prevent metallic debris from passing to the rail and injectors, that would pretty much eliminate both of the major modes of failure previously encountered on the CP4. Add to this any other material revisions changes they made, and I’d say the pump has been worked over pretty well. Given the current automotive climate, and the position Stellantis finds themselves in, I don’t believe anyone involved in this trucks release wanted a repeat performance of the past.
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Ford has employed all of this other than the isolated lube circuit.

My honest opinion, is this is that pump WITH the addition of the isolated lube circuit.

After all , why with all of these great changes to the pump (redesigned pistons and locating pins) do we need to have the lubrication circuit completely separate from the rest of the fuel system? Does the CP3 have an isolated lube circuit?

Could it be that the "CP8" is still failing in the Ford and GM trucks with their pinned plungers and Ram demanded that Bosch separate the lubricaiton circuit for the 2025 HD Ram?
 
H3LZSN1P3R said:
If you cant understand what the article is saying thats on you but this is not anywhere near the same as a CP4 from all the changes. They literally took all the failure points from the CP4 and eliminated them and then made a separate loop to be sure on the off chance of a failure it only takes out the pump.

Plus the CP4 had a 4% failure rate which is still almost nothing in the big picture
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Im not Canadian, I understand just fine.


blow kiss.gif
 
gimmie11s said:
Ford has employed all of this other than the isolated lube circuit.

My honest opinion, is this is that pump WITH the addition of the isolated lube circuit.

After all , why with all of these great changes to the pump (redesigned pistons and locating pins) do we need to have the lubrication circuit completely separate from the rest of the fuel system? Does the CP3 have an isolated lube circuit?

Could it be that the "CP8" is still failing in the Ford and GM trucks with their pinned plungers and Ram demanded that Bosch separate the lubricaiton circuit for the 2025 HD Ram?
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Yes, CP3 and the 19-20 and 21-24 derivatives have always had the isolated lube circuit. That's part of what made them so robust.
 
H3LZSN1P3R said:
...... by the sounds of it, it has been tested more than a CP3 ever has.
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That's the dumbest post of the day. Not surprising considering the author.

Do you have any idea how many CP3's are on the road and for how long/miles driven?
 
gimmie11s said:
That's the dumbest post of the day. Not surprising considering the author.

Do you have any idea how many CP3's are on the road and for how long/miles driven?
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I have never seen or heard of one going through a torture test like they claim to have done to the CP8. Im aware how many thousand's if not millions of CP3s are out there does not mean they underwent any torture testing.

There are also hundreds of thousands of CP4s out there that have not failed between the big 3 automakers not including the ones in europe, you people get your Chicken little mindset and think the sky is falling because this new pump looks like a CP4.
 
I would wager Cummins is getting a darn good deal on these CP8's from Bosch to make up for all of the CP4 failures.

Duramax dumped Bosch and went to the Denso HP4 pump. Bosch's rep is in serious trouble due to the ubiquitous CP4 fails. Bosch is probably bending over giving them to Cummins dirt cheap. My bet is that CP8 is one heck of a good pump- Bosch's reputation depends on it.
 
beendarenback said:
I would wager Cummins is getting a darn good deal on these CP8's from Bosch to make up for all of the CP4 failures.

Duramax dumped Bosch and went to the Denso HP4 pump. Bosch's rep is in serious trouble due to the ubiquitous CP4 fails. Bosch is probably bending over giving them to Cummins dirt cheap. My bet is that CP8 is one heck of a good pump- Bosch's reputation depends on it.
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Ram pushed for the CP4, not Cummins.
 
beendarenback said:
I would wager Cummins is getting a darn good deal on these CP8's from Bosch to make up for all of the CP4 failures.

Duramax dumped Bosch and went to the Denso HP4 pump. Bosch's rep is in serious trouble due to the ubiquitous CP4 fails. Bosch is probably bending over giving them to Cummins dirt cheap. My bet is that CP8 is one heck of a good pump- Bosch's reputation depends on it.
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"CP8" lol.

"Revised internal geometry for the cam rollers and pistons which improves design robustness".

What on earth does that mean?

I cant wait until someone takes a CP8 apart so we can see what ACTUALLY is different than the CP4 it's design is based off of.
 
gimmie11s said:
"CP8" lol.

"Revised internal geometry for the cam rollers and pistons which improves design robustness".

What on earth does that mean?

I cant wait until someone takes a CP8 apart so we can see what ACTUALLY is different than the CP4 it's design is based off of.
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Well they also claim they have separate pump lube and supply chambers, just like the CP3, so there's that.
 
CP4 roller and bucket:IMG_4228.jpeg

CP8 Roller and bucket:
IMG_4225.jpegIMG_4226.jpeg

CP4 pump body:
IMG_4219.jpegIMG_4220.jpeg
IMG_4230.jpeg
IMG_4218.png


CP8 pump body:
IMG_4223.jpegIMG_4224.jpeg
(Note that there is no mechanical gear driven feed pump on the back of the CP8 for this specific engine application. The in-tank supply pump on the 2025+ trucks has been upgraded for more flow to accommodate this design change.
 

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So I am assuming that the in tank pump does not see any filtration. Is it a similar gear pump style ? I am just assuming that the pressures are under 100 psi ?
 
HarryN said:
So I am assuming that the in tank pump does not see any filtration. Is it a similar gear pump style ? I am just assuming that the pressures are under 100 psi ?
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Tank pump would likely be a screen only, as in previous years and then the fuel goes through a multi-stage filtration process accomplished by the dual filter element housing mounted to the engine. I’m not sure what current flow or delivery pressures are to the CP8
 
mbarber84 said:
It’s a substantial upgrade over the CP4 in multiple areas. The pump was torture tested beyond any reasonable extent to what it would experience in real world conditions and excelled in every one of them.
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Interesting stuff indeed. In what areas do you think the upgrades are substantial? The pistons look to have been lightened and that roller is now MUCH much larger. Definitely a good thing.

I still don't see anything that prevents the buckets from rotating in their bores which will destroy any roller no matter how large.

Unless im missing it somewhere.

Great pictures though... appreciate you sharing.
 
gimmie11s said:
Interesting stuff indeed. In what areas do you think the upgrades are substantial? The pistons look to have been lightened and that roller is now MUCH much larger. Definitely a good thing.

I still don't see anything that prevents the buckets from rotating in their bores which will destroy any roller no matter how large.

Unless im missing it somewhere.

Great pictures though... appreciate you sharing.
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Given the grooves in the side of the bores and the slot/hole in the bucket, I'd expect there's a part we're not seeing.
 
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