2025+ Flat Tappet Conversion

[usafakid09]

Looks like Hamilton has developed a kit for the 2025+ engines. And it's almost $1k more than the 2019-2024 system, with customer-supplied rocker arms that have to be converted.

2025-2026 Flat tappet conversion kit™

Hamilton Cams Complete Kit for Cummins Engines Strength, durability, and precision—those are the hallmarks of our Hamilton Cams flat tappet conversion kit™. From forged steel camshafts...

hamiltoncams.com

 

[MacksRam]

Looks like Hamilton has developed a kit for the 2025+ engines. And it's almost $1k more than the 2019-2024 system, with customer-supplied rocker arms that have to be converted.

2025-2026 Flat tappet conversion kit™

Hamilton Cams Complete Kit for Cummins Engines Strength, durability, and precision—those are the hallmarks of our Hamilton Cams flat tappet conversion kit™. From forged steel camshafts...

hamiltoncams.com

I sure hope these kits are NOT needed in the 2025-2026 engines. As spending this $3999 plus tax and the labor to install would add up to a major expense.
I have a friend that has had both a 2022 and 2023 Ram 2500 and has had no issues with the lifters/engine.
Does anyone know of the factory hydraulic lifters/pushrods/cam/rocker arms that has failed in ANY 2025 Cummins at this point?

 

[mbarber84]

This one just showed up in one of my other groups. 25 cab and chassis (5500) with 9,600 miles on it. Not sure of idle hours but I’m sure they probably weren’t low being a C&C. I’m sure idle time played a contributing part in this failure, but suffice it to say this valvetrain doesn’t look to be any more robust. Much of it is identical to the 19-24 trucks or just slightly modified for the new block and head.

 

[Trash Panda]

Experiencing a failure of that magnitude before 10k miles, only to have the exact same parts put back in, would drive me actually insane.

That’s a nasty failure for such a low mileage truck.

 

[mbarber84]

Experiencing a failure of that magnitude before 10k miles, only to have the exact same parts put back in, would drive me actually insane.

Especially if the tech putting new parts in doesn’t take the time to inspect said parts thoroughly before installing, and misses something like this:

That’s a nasty failure for such a low mileage truck.

Indeed. Like I said, I’m sure component quality probably played a roll here, and likely idle time too. I just don’t know for sure.
I do know that this valvetrain is largely the same as 19-24 with few minor tweaks. The Cummins side of this equation wants to change the valvetrain substantially, just not sure how or if the Stellantis side will play ball. Might see something in 27

 

[kirk-35]

With all of the pushrods looking like that I'd suspect a lubrication issue is the culprit in those photos. It looks like they were run dry.

 

[mbarber84]

With all of the pushrods looking like that I'd suspect a lubrication issue is the culprit in those photos. It looks like they were run dry.

That type of premature wear is pretty common for these trucks. Happens more than it should. Which is partly why I think we’re going to see a design change in the very near future.

 

[DarkHorse8]

And I’m still waiting.

 

[Rowdy Dalton]

That type of premature wear is pretty common for these trucks. Happens more than it should. Which is partly why I think we’re going to see a design change in the very near future.

Not if people keep buying what is still being made. Has there been a significant drop in sales for the Ram diesels? Is Cummins going to refuse to build these engines for Stellantis, to save their reputation over profit?

 

[Old time trucker]

The 2025 engines still have this issue, check out Josh’s Truck Stuff on you tube.

 

[MacksRam]

That type of premature wear is pretty common for these trucks. Happens more than it should. Which is partly why I think we’re going to see a design change in the very near future.

mbarber84,
You are right-- these valve/pushrod/rocker arm/lifter related issues should NOT be happening.
But here is the deal--I have friends that own and have owned the 19-24 models--NONE of them have ever had any valve issues with them. One friend had a 2022 and now has a 2023--he still runs 15w-40 oil---no issues with either truck. My friend is a car dealer and has personally owned and sold MANY of these trucks--never had one with these issues.
The point: Are there really that many 2019-2025 models failing? Does anyone have any legitimate statistics as to the number of 19-25's that have failed?

 

[Bighorn NC]

Is the flat tappet conversion a proven fix. I wonder what the highest miles is on a conversion? Fingers crossed on my 2023. At this time the 2003 is getting the majority of use.

 

[mbarber84]

mbarber84,
You are right-- these valve/pushrod/rocker arm/lifter related issues should NOT be happening.
But here is the deal--I have friends that own and have owned the 19-24 models--NONE of them have ever had any valve issues with them. One friend had a 2022 and now has a 2023--he still runs 15w-40 oil---no issues with either truck. My friend is a car dealer and has personally owned and sold MANY of these trucks--never had one with these issues.
The point: Are there really that many 2019-2025 models failing? Does anyone have any legitimate statistics as to the number of 19-25's that have failed?

Enough that the Cummins side of the equation wants to change the design. That speaks volumes in its own right.