Cracked blocks

[Stroked777]

you have just misinformed yourself as why they crack

 

[jimdawg185]

Ive got to pull the valve covers off to clean it after my block cracked. Blue Devil seemed to work, and I am changing to Evans as to run no pressure in the system (its not leaking at all when its not running). Would it be a good idea to pull those four studs and coat them with something as well. And if the rest were at 325, what should I re torque these four to?

 

[Morgan@Midwest Diesel & Auto]

If the manufacturer calls for it, then that's how it was designed. Factory torque spec on a 6.4 is even torque across the holes. Deviating from that will net you a different (And undesirable) result.


Of course it will crack where it's weakest. Once the stud bottoms out, it is trying to drive the threads up out of the hole - the hole will crack wherever it is weakest.



I'm not trying to tell you how to do your job. If torquing the bolts unevenly works for you, then great. If those heads ever come off again, they will be trash as you will run out of the factory valve recession range trying to take enough material off to get them straight again.

Well, I'm going to have to disagree from experience. Not theories. But hey I guess all the theories mean more than real life experiences, real engines and real heads?

Alright boys, back to work. You all keep cracking your blocks and wondering why. :thumbup:

I know why they crack. Never wondered a minute. Never had an issue since the changes. But that's ok. I'll keep on keepin on. When you un lube a set of studs and it still cracks (like the ones we've seen already) I'll let you in on our torque method.

Sorry for wanting to clear the air of the bottoming out studs bs. Just like telling the truth brought on by facts. No disrespect towards you. But you could sit back and listen to others.

Have a nice day.

 

[HOOV3R]

So how many 6.4 head gasket jobs have you done SVTDanny? You seemed pretty proud doing the one set in your truck with a craftsman tool kit in your driveway, so I'm guessing that's the only one. Maybe you should try learning something here from the guys that do it every day, instead of trying to tell them they're all wrong.

 

[capt dong]

then to sum it up some blocks are more prone to cracking because theres less material around certain holes and to ease the stress the torque is decreased to 250 ft lbs on the head studs?

 

[Crack85]

On the stud that has the less material around it....

 

[powerstroked08]

Simply put yes. And honestly since that discovery I don't know of any other cracking by reputable shops.

 

[Dzchey21]

Anyone running over 70 psi of boost at 250 ft lbs and not puking?

 

[Crack85]

Anyone running over 70 psi of boost at 250 ft lbs and not puking?

That's for ppl running ARPs, custom aged or H11?

 

[Morgan@Midwest Diesel & Auto]

Anyone running over 70 psi of boost at 250 ft lbs and not puking?

I'm not 100%. I know in the 60's for sure. I'll have one soon. The pull trucks at 225.

 

[co04cobra]

Anyone running over 70 psi of boost at 250 ft lbs and not puking?

My WG is opening right at 70 since I changed setups. We went back to 230 and mine isn't puking YET. I am gun shy and have my doubts.


Only been 5K or so miles since new gaskets and I think I've only hit the WG twice.

Running Elites custom aged studs.

 

[SVTDanny]

So how many 6.4 head gasket jobs have you done SVTDanny? You seemed pretty proud doing the one set in your truck with a craftsman tool kit in your driveway, so I'm guessing that's the only one. Maybe you should try learning something here from the guys that do it every day, instead of trying to tell them they're all wrong.

The 6.4 is nothing special. Uneven torque of the studs will cause issues. My chambers were down 3 to 4 thou below the rest of the surface of the heads. Think about that - there is enough torque in the cylinder to warp a 3.74" thick piece of cast iron that much, what do you think it's going to do to that same head that has uneven clamping forces on it? I took just enough material off to clean the heads up and my valve recessions were at .00215" and .00225" - Ford specs say the minimum is .0017". My heads, with even torque, are already 5 thou from being garbage.

And if someone can't understand that whether the bolt bottoms out in the block or on the deck, it will still cause a crack at the weakest point in the hole - that's on them.

An engineering, machining, and engine building background tells me all I need to know about why blocks are cracking. I see it every day. I don't need internet experts to tell me their theories. I guess I had mistaken this thread for being one open to actual technical discussion. Moving on.

 

[Morgan@Midwest Diesel & Auto]

The 6.4 is nothing special. Uneven torque of the studs will cause issues. My chambers were down 3 to 4 thou below the rest of the surface of the heads. Think about that - there is enough torque in the cylinder to warp a 3.74" thick piece of cast iron that much, what do you think it's going to do to that same head that has uneven clamping forces on it? I took just enough material off to clean the heads up and my valve recessions were at .00215" and .00225" - Ford specs say the minimum is .0017". My heads, with even torque, are already 5 thou from being garbage.

And if someone can't understand that whether the bolt bottoms out in the block or on the deck, it will still cause a crack at the weakest point in the hole - that's on them.

An engineering, machining, and engine building background tells me all I need to know about why blocks are cracking. I see it every day. I don't need internet experts to tell me their theories. I guess I had mistaken this thread for being one open to actual technical discussion. Moving on.

Well thank you for your background and what it tells you. Wasn't trying to be a dick but since you told everyone how little we all know and how were wrong, I think it's best that you step out.

1: you only have a theory. So please tell me how many you have had cracked and in your possession for failure analysis?

2: during your failure analysis did you find that there were marks in the bottom of the stud hole causing your theory to be proved correct?

3: have you been able to see multiple cracked blocks with the same exact results to back your claim?

4: How much stress at what torque does an arp 2000 16mm stud place on the block? How much cylinder pressure will that clamping force hold back before that material of the studs yield given the surface area of the chamber forcing them to stretch?

5: how many engines have you studded since then? Did you pilot some new torque procedure on your own 6.4 making over 1000hp to see if it would work before telling the masses?

6: do you have multiples of proven trucks since then running that same sequence and torque to prove that it works?

I can say I have.

Soo...... are you really sure you want to call us a bunch of "internet experts"? What do you have to refute these FACTs I present, that I've lived and breathed. Or is it just a theory based on your background?

Check your facts please. This didn't have to go this far, but your ego got in the way to prove everyone wrong.

 

[webb06]

Well thank you for your background and what it tells you. Wasn't trying to be a dick but since you told everyone how little we all know and how were wrong, I think it's best that you step out.

1: you only have a theory. So please tell me how many you have had cracked and in your possession for failure analysis?

2: during your failure analysis did you find that there were marks in the bottom of the stud hole causing your theory to be proved correct?

3: have you been able to see multiple cracked blocks with the same exact results to back your claim?

4: How much stress at what torque does an arp 2000 16mm stud place on the block? How much cylinder pressure will that clamping force hold back before that material of the studs yield given the surface area of the chamber forcing them to stretch?

5: how many engines have you studded since then? Did you pilot some new torque procedure on your own 6.4 making over 1000hp to see if it would work before telling the masses?

6: do you have multiples of proven trucks since then running that same sequence and torque to prove that it works?

I can say I have.

Soo...... are you really sure you want to call us a bunch of "internet experts"? What do you have to refute these FACTs I present, that I've lived and breathed. Or is it just a theory based on your background?

Check your facts please. This didn't have to go this far, but your ego got in the way to prove everyone wrong.

:rockon:

 

[TXAG07]

Drop the mic....

Well said Morgan.

 

[Dzchey21]

That's for ppl running ARPs, custom aged or H11?

anyone, but mostly arp and elite studs none h11

 

[drunk on diesel]

Well thank you for your background and what it tells you. Wasn't trying to be a dick but since you told everyone how little we all know and how were wrong, I think it's best that you step out.

1: you only have a theory. So please tell me how many you have had cracked and in your possession for failure analysis?

2: during your failure analysis did you find that there were marks in the bottom of the stud hole causing your theory to be proved correct?

3: have you been able to see multiple cracked blocks with the same exact results to back your claim?

4: How much stress at what torque does an arp 2000 16mm stud place on the block? How much cylinder pressure will that clamping force hold back before that material of the studs yield given the surface area of the chamber forcing them to stretch?

5: how many engines have you studded since then? Did you pilot some new torque procedure on your own 6.4 making over 1000hp to see if it would work before telling the masses?

6: do you have multiples of proven trucks since then running that same sequence and torque to prove that it works?

I can say I have.

Soo...... are you really sure you want to call us a bunch of "internet experts"? What do you have to refute these FACTs I present, that I've lived and breathed. Or is it just a theory based on your background?

Check your facts please. This didn't have to go this far, but your ego got in the way to prove everyone wrong.

 

[madman1234509]

Lol. All I know is my arp studs were torqued to spec with a brand new torque wrench and my block isn't cracked...... with a 911hp dyno graph.

I do believe caution should be taken with head stud jobs. Ensuring you have a properly calibrated torque wrench for the arp torque levels is very important. A lot of small shops don't deem it cost effective to buy a 500 dollar torque wrench for a build they may do once, could be an issue for this application. Esp for a block the has a stud hole in spot that has a huge risk for cracking into the lifter valley.

 

[forcefed6.4ford]

I shelled out 800.00 for good torque wrenches. 1 for the studs and a smaller on for everything else. 800.00 is cheap compared to the alternative.

 

[Crack85]

I shelled out 800.00 for good torque wrenches. 1 for the studs and a smaller on for everything else. 800.00 is cheap compared to the alternative.

Snap on?