6.7 seeping antifreeze. Head gasket?

[Mark Nixon]

Please look at the pics attached.

Picked up a 2008 engine as a core, as my standard procedure, I removed the head to find only that #1 and #5 cylinder pistons were not sooty and have an almost steam washed look to them.
The cylinders themselves are totally untouched.

Upon closer inspection, I find that the head has been replaced, as well as surfaced.

Do you guys agree that this could be a simple failure to re-torque properly?
It wasn't studded, they re-used the headbolts.

Mark.

 

[zfaylor]

straight edge the block and head? A lot of people think they can slap a gasket things and all will be well.

 

[Mark Nixon]

Not my style to just slap it back together without checking.
That's why I am here asking.

If it were something I wanted to put together for myself, everything I'm reading says to make sure it's flat, fire ring the head and stud the biitch.

Mark.

 

[CorneliusRox]

If it's actually flat and torqued right, you can make them live for a very long time without fire rings. Just throwing that out there. It's easy to get the impression you need fire rings when most people posting about it are >1,000 hp.

 

[blackmega3500]

It's a safe bet to say someone had the truck modded blew the gasket and ran it long enough bad and it likely cracked the original head. Then returned as much to stock and ditched it to let it become someone elses problem.

Fire rings have their place for sure, but a properly torqued and true head can definitely hold respectable power.

I personally am a big believer in hot torques and many skip this.

 

[Mark Nixon]

I agree, it's probably someone not taking the time to re-torque and got in a hurry.
On the same token, how do they sometimes run hundreds of thousands of miles right from Cummins on the factory seal?

It's likely going to be an engine that's sold as it sits.
I was considering using it, but I'm one of the least likely people to do that, as I am not one who puts things together. LOL

Mark.

 

[CorneliusRox]

On the same token, how do they sometimes run hundreds of thousands of miles right from Cummins on the factory seal?

They use something called DC tools on the assembly line. You can control torque and RPM. So you can drive a fastener down fast to say 100 ft-lbs, slow it down for the last 20 ft-lbs, and really slow for the last 5 ft-lbs. Pair that with proper torque sequence, very clean components, and designed to spec assembly lube, and you've got a recipe for low warranty! :Cheer:

Also, it seems most people don't realize torque does not equate to clamp load, and the only two things your care about are clamp load, and uniformity of it.
When you're trying to hit a torque, using a proper lubricant (likely something with moly) and a hard clamping surface (to keep friction and embedment low), you increase your clamp load and consistency. This is extremely controlled on the assembly line. You never know what some guy did in his driveway.

 

[Snedge]

On the same token, how do they sometimes run hundreds of thousands of miles right from Cummins on the factory seal?


Mark.

Moslty because they are stock and actually designed to run that long.

I can't say I've seen many head gasket failure on equipment that's left alone.