Blown head gaskets with ARP's

[MrOneEyedBoh]

I seen those little bolts that come with the 625s. What are they for/doing?

 

[mcdaniel1991]

I think your talking about the upper head bolts.?

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[MrOneEyedBoh]

Possibly. They are like little m10 bolts maybe? I don't know what size honestly

 

[Dirty_Stroke]

Hey guys I couldn't ever get a for sure fix for the head gaskets, so I traded the truck for a 2010 6.7 Cummins. I will miss the whistle and sound of the 6.0. Good luck guys finding a solution for the studs.

 

[97strokn&smokn]

I hate to be the bad news bandit but there is a good chance you will pop a hg on the dodge also. I have seen a bunch of the 6.7 pop gaskets with delete tuning. Good luck though

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[sootie]

I hate to be the bad news bandit but there is a good chance you will pop a hg on the dodge also. I have seen a bunch of the 6.7 pop gaskets with delete tuning. Good luck though

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LOL yup. basically the plague of the cummins boyz, watch out for it eating the #6 piston or cracking the block...

 

[swinky]

Who cares? It's easy as Hell to do.

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[Dirty_Stroke]

I hate to be the bad news bandit but there is a good chance you will pop a hg on the dodge also. I have seen a bunch of the 6.7 pop gaskets with delete tuning. Good luck though

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Yea I've already been told about that. I plan to stud it before i do anything further. Idk that I'm going to build this truck for racing like I did the 6.0. I'm thinking just the basic mods. It's already on 6 inches and 37's.

 

[silverbullet4x4]

LOL yup. basically the plague of the cummins boyz, watch out for it eating the #6 piston or cracking the block...

Since when do they crack blocks?

 

[RedRice589]

Yea I've already been told about that. I plan to stud it before i do anything further. Idk that I'm going to build this truck for racing like I did the 6.0. I'm thinking just the basic mods. It's already on 6 inches and 37's.

Still a quitter.... ointlaugh:

 

[blackcloudpsd03]

What is the back pressure differences from a bigger vgt turbo vs a non vgt?

 

[sootie]

Since when do they crack blocks?

i guess often enough for me to have personally seen two of them.

 

[blackcloudpsd03]

the 6.7? cracked block's??? you learn something new every day. only ones i know about is the 53 block witch im sure cummins handled along time ago.

 

[TooMuch03]

No. But what I can guarantee you, is that the elastic modulus chosen for the ARP 425 is 60% below the maximum stress/strain that the stud will ever see for the average modded truck. That is MINIMUM engineering standards for today. So you push the stud another 20-30% at 700hp, and maybe what, 50psi overall of boost?...you're still not yielding the stud to permanent deformation (can be a few thousandths of an inch). The fatigue from the cyclic loading, creep, and heat cycles allotted for the stud will not be reached in a period under a year, at 700hp. Fact. There's no debate.


Another thing...Alot of guys end up impact the elastic modulus by over torquing the stud than it was designed for. You've now held the stud to a 20-40% increase before the stud is yielding torquing to 250ft/lbs. There is a reason why torque specs need to be followed. Kobalt/craftsman torque wrenches, not paying attention to sequences, etc account for these failures too that you don't hear about.

The failures were from something that was overlooked and or poorly done.

1000hp, nitrous, 70psi? You will yield them at some point.

I am not sure what you are trying to say in this post,but using big words is a good way to keep people from disputing your point. The elastic modulus (aka modulus or elasticity, aka Young's modulus) is a material property of the alloy used in the stud. It describes the relationship between stress (tensile force per cross-sectional area) and the strain (deflection per length) in the materials region if elastic deformation, and is not something you can exceed or change by over or under torquing the stud. This is a fact. The manufacturer provides a torque value that they feel will safely load the stud to their chosen stress value, typically 60-70% of the yield stress (the stress value at which the material ceases elastic deformation and begins plastic deformation). The important thing to realize here is that the stud does not have to reach it's yield stress for your headgaskets to leak. It only needs to exceed the preloaded stress that was established during the installation. If it never reaches that stress, the stud will not deform, and heat cycles and fatigue will have virtually no impact. If it does, the stud will deform, the head gasket will leak. Then, once the load is removed, the stud will return to it's previous length and the beauty of mls gaskets is that they will reseal. If you somehow reach the yield stress of your studs you have serious issues.

I do have to agree with the point about over-torquing studs. People seem to think that if the studs hold at a certain torque value then they will hold all the better at higher torque values. Or, they think that because a stud gets torqued less that it has less "clamping force". By over torquing a stud all you do is increase the preloaded stress on the stud and move it closer to its yield stress. The manufacturer specifies a given torque value based on rotational capacity testing to determine what torque value will give you approximately the stress that they want(with a factor of safety for variance in torque wrenches). The testing is done under a specific set of conditions that they try to have the customer replicate, hence why they recommend or provide a certain lubricant. Unfortunately, torque is one of the least accurate ways to estimate the actual tensile force that is being applied to the fastener. Things like strain gauges and load indicating washers are far more accurate, just not something the average mechanic is willing to deal with.

A whole other issue that has not yet been discussed is that the vast majority of headgaskets fail in between the studs and not at the studs themselves. This leads me to believe that heads may very well be deforming, not the studs. This would also explain why O rings have been very successful, where stock gaskets alone may have failed. Food for thought.

 

[MorganY]

I am not sure what you are trying to say in this post,but using big words is a good way to keep people from disputing your point. The elastic modulus (aka modulus or elasticity, aka Young's modulus) is a material property of the alloy used in the stud. It describes the relationship between stress (tensile force per cross-sectional area) and the strain (deflection per length) in the materials region if elastic deformation, and is not something you can exceed or change by over or under torquing the stud. This is a fact. The manufacturer provides a torque value that they feel will safely load the stud to their chosen stress value, typically 60-70% of the yield stress (the stress value at which the material ceases elastic deformation and begins plastic deformation). The important thing to realize here is that the stud does not have to reach it's yield stress for your headgaskets to leak. It only needs to exceed the preloaded stress that was established during the installation. If it never reaches that stress, the stud will not deform, and heat cycles and fatigue will have virtually no impact. If it does, the stud will deform, the head gasket will leak. Then, once the load is removed, the stud will return to it's previous length and the beauty of mls gaskets is that they will reseal. If you somehow reach the yield stress of your studs you have serious issues.

I do have to agree with the point about over-torquing studs. People seem to think that if the studs hold at a certain torque value then they will hold all the better at higher torque values. Or, they think that because a stud gets torqued less that it has less "clamping force". By over torquing a stud all you do is increase the preloaded stress on the stud and move it closer to its yield stress. The manufacturer specifies a given torque value based on rotational capacity testing to determine what torque value will give you approximately the stress that they want(with a factor of safety for variance in torque wrenches). The testing is done under a specific set of conditions that they try to have the customer replicate, hence why they recommend or provide a certain lubricant. Unfortunately, torque is one of the least accurate ways to estimate the actual tensile force that is being applied to the fastener. Things like strain gauges and load indicating washers are far more accurate, just not something the average mechanic is willing to deal with.

A whole other issue that has not yet been discussed is that the vast majority of headgaskets fail in between the studs and not at the studs themselves. This leads me to believe that heads may very well be deforming, not the studs. This would also explain why O rings have been very successful, where stock gaskets alone may have failed. Food for thought.

You're guilty of the same, I'm right there with you.

I'm referring to moving along the elastic modulus curve of the stud itself in that post, which includes the material and CSA of the material being tested. The point I was trying to get across was to those who were saying the stud has worn or deformed. Which is extremely incorrect. Which you have agreed with, highlighted in red.

 

[RedRice589]

Just stop... I'm a simple man and that's difficult lol

 

[TooMuch03]

Exactly, I don't think anyone is yielding these studs. I think the issue is not the studs, but rather the heads themselves, maybe the low number of studs to an extent.

 

[alwil]

Exactly, I don't think anyone is yielding these studs. I think the issue is not the studs, but rather the heads themselves, maybe the low number of studs to an extent.

I said this once and people jumped down my throat, I think there is too much clamping area per stud......

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[swinky]

That's pretty obvious. I can't imagine anybody saying 6 per cylinder wouldn't hurt.

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[SICKS LITER]

Hey guys I have a blown or severely leaking head gasket in my 05. The truck has been studded for about 3 years maybe a little longer. I used ARP 425's with OEM gaskets and had the heads machined perfectly flat. I'm only running 155's and a 64.7mm VGT. I'm stuck in the boat of fix it again and hope it holds or trade it off for a newer truck. The end goal with this truck was 190's or 205's with a matching charger. What does it take to make this motor hold that kind of power? I'm not easy on it by any stretch of the imagination. I've been told ARP 625's with OEM gaskets would hold. I've also checked into O-ringed heads. I need opinions from people that have 650+ Hp 6.0's. How long they've held up and what's the setup?

How was the block prepped when the headgaskets were done? Was it measured with a straight edge? Has the truck ever blown the gaskets before if so how long was it driven that way?