Cracked blocks

[webb06]

And you might be the fastest. You built 3 motors in like 4 hours

Haha I doubt that. Looking back now I wouldn't trade the experience I gained for the money I spent. It was a major headache but it was fun and I leaned a lot

 

[SVTDanny]

Two of the most educated 6.4 mechanics are giving you insight on the ACTUAL reason why the blocks crack and you're still trying to prove them wrong? Goodluck. From personal experience.....twice.....they cracked exactly where Morgan and Tadd said they do. Not because the stud bottomed out

If you want to turn this into a pissing match, go right ahead. I've said what I had to say to try and help people out.

 

[Wayne]

SVTDANNY: you really need to understand where these guys are coming from. I've cracked a couple blocks myself, one being my own. Threads are perfectly clean prior, engine oil applied to block side threads, top of studs marked to ensure they don't thread in further, and enough assy lube to where it squishes out of the bottom and top of threads as well as top and bottom of the washers. Torqued to 210 lb/ft knowing for a fact that studs did not bottom out, and still got small cracks. Cooling system sealer stopped mine, but the customers' block had to be replaced. Both of the guys you're arguing with are well known performance shop owners and engine builders. I can't say how many engines Morgan has built, but just as a reference, Tadd (fast6.0) designed the first 6.4 studs, and has built dozens of 6.4 race engines.

 

[4.0l sahara]

Anybody ever torque just the studs in the crack prone holes to a lesser torque? Thought I read that posted somewhere?

 

[SVTDanny]

SVTDANNY: you really need to understand where these guys are coming from. I've cracked a couple blocks myself, one being my own. Threads are perfectly clean prior, engine oil applied to block side threads, top of studs marked to ensure they don't thread in further, and enough assy lube to where it squishes out of the bottom and top of threads as well as top and bottom of the washers. Torqued to 210 lb/ft knowing for a fact that studs did not bottom out, and still got small cracks. Cooling system sealer stopped mine, but the customers' block had to be replaced. Both of the guys you're arguing with are well known performance shop owners and engine builders. I can't say how many engines Morgan has built, but just as a reference, Tadd (fast6.0) designed the first 6.4 studs, and has built dozens of 6.4 race engines.

I'm not looking for a pissing match. Just offering my input. I have plenty of experience of my own and see people screwing up stud installs all the time.

You aren't supposed to oil the block threads on ARP studs.

 

[smokinstroker]

Anybody ever torque just the studs in the crack prone holes to a lesser torque? Thought I read that posted somewhere?

I think it has been discussed before. I would believe this would cause an un-even clamping load on the head across the surface. Someone with more of a physics or engineering background can probably confirm.

 

[Crack85]

I think it has been discussed before. I would believe this would cause an un-even clamping load on the head across the surface. Someone with more of a physics or engineering background can probably confirm.

It will definitely be uneven clamping....from an engineering background, if u are dropping the torque I would do it across the board so that clamping force is the same.

 

[forcefed6.4ford]

I lowered my torque by 10ftlbs on the problematic holes. No issues (knock on wood) 1200miles since studding.

 

[Morgan@Midwest Diesel & Auto]

We lower the weak hole to 225. The rest go to 250. No issues on every 6.4 done like that for over a year now. Currently have 3 6.4's and two 6.0's in here doing engine builds. Nothing abnormal for us. The difference in the two torques does not affect the head. Not gonna warp a 6.4 head especially with it only being within 10% of each other. It would be a different story if it was an aluminum head.

 

[Morgan@Midwest Diesel & Auto]

Tell me which two holes have less material around them?

 

[Wayne]

You aren't supposed to oil the block threads on ARP studs.

#1: I was not using arp's in the example I gave.

#2: can you give me one legitimate reason why oil on the block side threads is not acceptable? How about red loctite, Teflon thread sealant or even a thin coat of gear oil? I have used all of these.

I realize you're trying to help here, but coming off as a know-it-all, telling experts what is, and is not acceptable is not doing you any favors.

 

[Breaking Habits]

Tell me which two holes have less material around them?

The one 3rd to the left of the 2nd one to the right ..

 

[Crack85]

Does he get a cookie

 

[SVTDanny]

It will definitely be uneven clamping....from an engineering background, if u are dropping the torque I would do it across the board so that clamping force is the same.

Definitely would not use uneven torque values. Pull a head off a truck that has been run like that and run a dial indicator across it. I guarantee it is warped.

#1: I was not using arp's in the example I gave.

#2: can you give me one legitimate reason why oil on the block side threads is not acceptable? How about red loctite, Teflon thread sealant or even a thin coat of gear oil? I have used all of these.

I realize you're trying to help here, but coming off as a know-it-all, telling experts what is, and is not acceptable is not doing you any favors.

The idea is to not have the stud turn in the block, that's why generous amounts of lube up top is essential. Lubing the threads that go into the block and promoting turning the stud into a bolt, causing this problem. You also hydrolock the air below the stud by oiling the threads. ARP does not even instruct to lube the block threads, and they are the manufacturer of the stud. But hey, I'm no expert.

 

[Morgan@Midwest Diesel & Auto]

Definitely would not use uneven torque values.

So your blanket statement covers all engines? I've built plenty of engines that call for different torques on certain studs. And how perfect do you think a standard torque wrench is? 1%? Nope 3-5% more like it.

Lubing the threads that go into the block and promoting turning the stud into a bolt, causing this problem.

So once again blanket statement? Since you can blow the stud hole out the bottom on a sbc means it what is happening here too?


I can take 10 blocks and torque 10 of them to 345# and all ten will be cracked in the same spot. All of them will be half way up the side in the lifer valley. Not in the bottom.

 

[SVTDanny]

So your blanket statement covers all engines? I've built plenty of engines that call for different torques on certain studs. And how perfect do you think a standard torque wrench is? 1%? Nope 3-5% more like

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.

So once again blanket statement? Since you can blow the stud hole out the bottom on a sbc means it what is happening here too?


I can take 10 blocks and torque 10 of them to 345# and all ten will be cracked in the same spot. All of them will be half way up the side in the lifer valley. Not in the bottom.

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.

 

[Stroked777]

Again Danny, Wayne wasn't using arp studs in his examples

 

[SVTDanny]

Again Danny, Wayne wasn't using arp studs in his examples

If we are talking about H11 studs, then yes. A DROP of oil on the threads is used to prevent them from corroding once in the block. Not for lubrication.

 

[Wayne]

If we are talking about H11 studs, then yes. A DROP of oil on the threads is used to prevent them from corroding once in the block. Not for lubrication.

WOW. :stupid:

 

[SVTDanny]

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