Cracked blocks

[powerstroked08]

My wife's truck has the 625's in it. We just ran the stud till it bottomed, then backed it out 3/4 turn. She put a strip of dye-chem on a stud edge, then torqued them down in 4 steps. The studs all turned about 1/2 turn back in, so no bottomed out studs. Did both my motors! And both of hers this way. No problems so far.

As for when the blocks are going bad, the ones that crack while torquing I could see. But, the ones letting go later down the road have me thinking, is it the clamping force plus heating/cooling cycles causing it, or could there be some very high cylinder pressures finding a weak spot?

A little off topic but your wife sounds pretty bad a$$. Not too many women have tuned up 6.4's. And now back on topic, I was curious if the ones that cracked later on so to speak, if they cracked maybe a little bit initially and then like you said with heat cycles opened up more over time.

 

[kdogg85]

She got to liking my truck, traded the TL off for hers. All downhill after that, not that I had to twist her arm or anything.

Anywho, that very well may be it. I was just thinking an explosion tries to find the easiest way out it can.

BTW, earlier in the thread someone mentioned a billet block, talk with LSM machine, they only advertise 7.3 and 6.0 blocks, but can make whatever you want. Paying dearly doesn't begin to describe it though. The left nut alone won't cut it. Iirc, a 6.0 block was around 25k.

 

[01PSD]

She got to liking my truck, traded the TL off for hers. All downhill after that, not that I had to twist her arm or anything.

Anywho, that very well may be it. I was just thinking an explosion tries to find the easiest way out it can.

BTW, earlier in the thread someone mentioned a billet block, talk with LSM machine, they only advertise 7.3 and 6.0 blocks, but can make whatever you want. Paying dearly doesn't begin to describe it though. The left nut alone won't cut it. Iirc, a 6.0 block was around 25k.

Holy dumb *** :jawdrop: I'll flint stone my $hit around LOL

 

[B585Ford]

Holy dumb *** :jawdrop: I'll flint stone my $hit around LOL

LOL

 

[powerstroked08]

Oh only 25K! Ok well here's both my nuts as well as my sack! Holy crap thats insane! I just dont understand why somebody just doesn't make either a siamese cylinder deal for the 6.4 or just thicken up the casting around the head bolt area. Don't get me wrong i'd love to have a billet block, but i'm also realistic!

 

[kdogg85]

Well if you look at it by the pound compared to some of the other mods we all do. Probably right in line. With that said, imagine a 500+ cubic inch motor under the hood. Wouldn't that be a real split slicker upper.

You may want to throw in a urethra for bargaining on free shipping?

Back to something topic related, didn't certain shops sonic check blocks at one time. It used to be used to check main webbing and such.

 

[Meniacal_Mark]

She got to liking my truck, traded the TL off for hers. All downhill after that, not that I had to twist her arm or anything.

Anywho, that very well may be it. I was just thinking an explosion tries to find the easiest way out it can.

BTW, earlier in the thread someone mentioned a billet block, talk with LSM machine, they only advertise 7.3 and 6.0 blocks, but can make whatever you want. Paying dearly doesn't begin to describe it though. The left nut alone won't cut it. Iirc, a 6.0 block was around 25k.

NGM said they can make a billet aluminum 6.4 block for $15k

 

[Fordtrucks]

NGM said they can make a billet aluminum 6.4 block for $15k

That right there would be bad ass!!

 

[Meniacal_Mark]

They said that price includes the engineering and design.

 

[SVTDanny]

Just wanted to bump this with some insight.

I just finished cleaning out the head bolt holes in my block. After 3 rounds of brake clean and air, I'm still blowing a ton of oil and garbage out of them. Failing to clean these out REALLY WELL will cause a cracked block.

Also, the lube packet that ARP supplies is never enough. The top threads, washer, and nut need to be smothered in lube or you will turn the stud into a bolt and drive it down into the block, cracking it.


Just my 2 cents.

 

[forcefed6.4ford]

When I did mine I blew them out then sucked them out with a ship vac until the holes were dry.

 

[duddy]

I used 4 cans of brake clean, to get to clean, and one more after for good measure.

 

[Morgan@Midwest Diesel & Auto]

Just wanted to bump this with some insight.

I just finished cleaning out the head bolt holes in my block. After 3 rounds of brake clean and air, I'm still blowing a ton of oil and garbage out of them. Failing to clean these out REALLY WELL will cause a cracked block.

Also, the lube packet that ARP supplies is never enough. The top threads, washer, and nut need to be smothered in lube or you will turn the stud into a bolt and drive it down into the block, cracking it.


Just my 2 cents.

Not saying your wrong but the reason they crack is because they have a weak area around 2 holes in each side of the block. They NEVER crack at the bottom of the hole. It's always at the side in the this area of the lifter valley. I've got 4 blocks here from various shops to prove it. All cracked in the same spot.

 

[duddy]

Not saying your wrong but the reason they crack is because they have a weak area around 2 holes in each side of the block. They NEVER crack at the bottom of the hole. It's always at the side in the this area of the lifter valley. I've got 4 blocks here from various shops to prove it. All cracked in the same spot.

DO you think there is a way to avoid cracking the holes, or is it just going to be a nature of the beast situation?

 

[SVTDanny]

Not saying your wrong but the reason they crack is because they have a weak area around 2 holes in each side of the block. They NEVER crack at the bottom of the hole. It's always at the side in the this area of the lifter valley. I've got 4 blocks here from various shops to prove it. All cracked in the same spot.

When the stud turns to a bolt and bottoms out, it will want to drive the threads up out of the block, and crack it at the weakest point. Tons of lube up top is key to proper stud installation, across all applications - not just these.

 

[Fast-6.0]

When the stud turns to a bolt and bottoms out, it will want to drive the threads up out of the block, and crack it at the weakest point. Tons of lube up top is key to proper stud installation, across all applications - not just these.

Totally agree with you that excess lube on the top threads is essential. And in some applications what you are referencing could in fact crack a block but in this application, the 6.4L Powerstroke, you are incorrect. Just like Morgan said, the crack is not at the bottom of the hole. Another tidbit of info that debunks what you are saying is that on an ARP stud, the threads bottom out on the deck before they even get close to the bottom of the hole. Checked into this along time ago. Not wanting be come across as a dick but you a stating something as a fact that many other people know to be untrue.

 

[Morgan@Midwest Diesel & Auto]

Totally agree with you that excess lube on the top threads is essential. And in some applications what you are referencing could in fact crack a block but in this application, the 6.4L Powerstroke, you are incorrect. Just like Morgan said, the crack is not at the bottom of the hole. Another tidbit of info that debunks what you are saying is that on an ARP stud, the threads bottom out on the deck before they even get close to the bottom of the hole. Checked into this along time ago. Not wanting be come across as a dick but you a stating something as a fact that many other people know to be untrue.

Agreed, it only has to with more force being applied to the block that it can take without cracking. 90% of the time it has to do with operator error, whether that be uncalibrated torque wrench or someone thinking that 300# with new lube is better than 275# ... Etc. We torque arp's to 250 and have zero issues.

 

[SVTDanny]

Totally agree with you that excess lube on the top threads is essential. And in some applications what you are referencing could in fact crack a block but in this application, the 6.4L Powerstroke, you are incorrect. Just like Morgan said, the crack is not at the bottom of the hole. Another tidbit of info that debunks what you are saying is that on an ARP stud, the threads bottom out on the deck before they even get close to the bottom of the hole. Checked into this along time ago. Not wanting be come across as a dick but you a stating something as a fact that many other people know to be untrue.

Trying to drive the stud into the hole when it's bottomed out on the deck or at the bottom or the hole will try and pull the threads out, causing a crack in the weakest spot. Again, just my 2 cents. I see cracked blocks of all sorts every single day from people not using enough lube.

 

[webb06]

Trying to drive the stud into the hole when it's bottomed out on the deck or at the bottom or the hole will try and pull the threads out, causing a crack in the weakest spot. Again, just my 2 cents. I see cracked blocks of all sorts every single day from people not using enough lube.

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

 

[powerstroked08]

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

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