Cracked Block

[SEABEE08FX4]

Of the thousands of studded 6.4s, a very very small handful have ever had this issue.

Not saying that this was the case with this one, just saying its a precaution that I personally take when I do them and I have not had an issue like this with any of the Fords or Dodges I have done.

 

[Morgan@Midwest Diesel & Auto]

Loosing coolant, lots of vapor out the ccv and the same greenish snot (pic) coming out the ccv.
[ATTACH=full]103678[/ATTACH]

I have had this same exact thing happen. Pulled the heads, changed gaskets (btw I use copper coat on all the gaskets, it seals the porosity on the top of the block that a lot of these have without pulling the engine to mill it) and it didn't come back. But the coolant was traveling up the stud and out on the top of the head. Made the nasty sludge you see here. Pasting the studs doesn't hurt and not bottoming studs out is highly recommended. This engine is currently down again for a complete build (for non coolant related issues) so the block is going to the machine shop for some cleaning, magna flux and resurfacing before being reused again.

 

[Morgan@Midwest Diesel & Auto]

first hand look at coolant that came out of a head stud bore. It had washed the oil away from that area and was losing a gallon of coolant every 500 miles or so. Made for some very nasty valve covers filled with oil pudding!

 

[golfer]

Here is a picture of a core 6.4L engine we use for mockup/measuring/etc..I had one of the guys in the shop pull the head so I could take a picture to let those, here interested, visualize what & where this 'casting' line is.

the casting line does intersect with the threaded bolt holes, but it is not anywhere near the bottom of the blind hole.

for what it's worth, we use the A1 studs exclusively for head fasteners,

installation for all applications is:
clean debris/fluid from the hole with brake clean & compressed air, install the new stud with a small amount of clean engine oil on (block side) threads, bottom it out in the block, and back off 1/4 turn prior to, installing, lube, nut, & torquing the nut.

 

[AllanB]

Here is a picture of a core 6.4L engine we use for mockup/measuring/etc..I had one of the guys in the shop pull the head so I could take a picture to let those, here interested, visualize what & where this 'casting' line is.

the casting line does intersect with the threaded bolt holes, but it is not anywhere near the bottom of the blind hole.

for what it's worth, we use the A1 studs exclusively for head fasteners,

installation for all applications is:
clean debris/fluid from the hole with brake clean & compressed air, install the new stud with a small amount of clean engine oil on (block side) threads, bottom it out in the block, and back off 1/4 turn prior to, installing, lube, nut, & torquing the nut.

Just curious why you would put a small amount of oil in the block side threads? It has no way to clear out of the hole. If it is put on the stud, when the stud is run in the hole, it will run all excess oil out of the hole, as apposed to putting oil in the hole and running any excess down to the bottom of the hole, with no way to exit. Not trying to second guess you. Maybe there is something I am not seeing here?

 

[golfer]

Just curious why you would put a small amount of oil in the block side threads? It has no way to clear out of the hole. If it is put on the stud, when the stud is run in the hole, it will run all excess oil out of the hole, as apposed to putting oil in the hole and running any excess down to the bottom of the hole, with no way to exit. Not trying to second guess you. Maybe there is something I am not seeing here?

brake cleaner + compressed air leaves the threaded hole dry as a bone...so a light coat of engine oil on the coarse side simply aids installation.

just good general practice for any engine fastener.

 

[white07psd]

Just thinking out loud but what about if you put a little bit of oil in the thread holes as a cushion for the stud against the block. Yes it wouldn't havent no where to go but could potentially keep the stud from bottoming out and cracking the block.

sent from the stool.

 

[SEABEE08FX4]

Just thinking out loud but what about if you put a little bit of oil in the thread holes as a cushion for the stud against the block. Yes it wouldn't havent no where to go but could potentially keep the stud from bottoming out and cracking the block.

sent from the stool.

It just gets squeezed out, if you turn the stud slowly you can hear it.

 

[tensixniner]

Just thinking out loud but what about if you put a little bit of oil in the thread holes as a cushion for the stud against the block. Yes it wouldn't havent no where to go but could potentially keep the stud from bottoming out and cracking the block.

sent from the stool.

It's just a thin film on the stud threads. Shouldn't be dripping off making a mess.
Head gaskets go on a clean dry surface.
Pretty sure it's explained in the head gasket write up in the west point section.

 

[Dustball8504]

If someone was going to build a motor from the ground up, what would you guys do from the start to help the block out?

 

[Fast-6.0]

the casting line does intersect with the threaded bolt holes, but it is not anywhere near the bottom of the blind hole.

The cracks we have seen aren't at the bottom of the hole. The crack is in the threads or worst case the crack goes into the lifter valley.

 

[White_monster]

Deck the block and have it cleaned at the machine shop. Run a tap through the bolt holes to make sure they are clean. Clean the stud holes out and I'd use a little bit of thread sealant on the studs just to be sure. I'd also tap the oil gallery ends for threaded plugs instead of pressed in frost plugs. My opinion though

 

[Dustball8504]

Deck the block and have it cleaned at the machine shop. Run a tap through the bolt holes to make sure they are clean. Clean the stud holes out and I'd use a little bit of thread sealant on the studs just to be sure. I'd also tap the oil gallery ends for threaded plugs instead of pressed in frost plugs. My opinion though

Good info, I'm saving this for future use

 

[Fast-6.0]

Who did the stud job? The proper way of installing the studs is to bottom them out and then back off half a turn. The put the washer and nut on and bottom the nut down hand tight without letting the stud turn, because when you go to torque the nuts the stud will turn. And if it doesn't have that buffer room to keep going deeper in the stud hole it will bottom out and crack the block.

Not saying what you are doing is wrong at all but I do have a little more insight based on your comments.

The ARP and A1 studs don't bottom out in the bottom of the blindhole, they stop at the top of the deck. So I don't see this issue as installer error. Nor do I see the 1/2 turn or 1/4 turn backed off doing anything to help or hurt this. The stud turns to bottom itself once torqued, and again it (both brands) stops when the threads at the top of the deck bottom out on the stud. A great distance from where the crack is occuring.

Just some thoughts.

 

[Morgan@Midwest Diesel & Auto]

If someone was going to build a motor from the ground up, what would you guys do from the start to help the block out?

Start with a new block for $2500. Save the $1200 or so you would have in machining the old block, have a better foundation and peice of mind.

 

[golfer]

If someone was going to build a motor from the ground up, what would you guys do from the start to help the block out?

I've been considering this all day...

We have been filling the 7.3L blocks (even for street use, above 550-600hp) using HardBlok for over 6 years. We also coat the dried/cured HardBlok with an epoxy sealer to prevent coolant circulation from picking up any 'cement' and passing it through the pump/cooler.

The 7.3L blocks have a casting line that radiates from the cam journals...which is where most 7.3L block failures occur...leaving the main caps and crank sitting in the oil pan as an assembly.

The only downside has been the added weight. For 5+ years, we wouldn't recommend building a 600+hp 7.3L withOUT filling the block, unless our bedplate were used.

We have engines with over 100k miles on them that are filled to @ 2" below the block deck...used daily..towing, etc.

Looking at the '08 core engine, and the relationship b/w the casting line and the threaded portion of the block...it appears that the fill would have to be pretttty high to get above the casting (parting) line to gain block rigidity, and minimize/eliminate casting breakage.

Unfortunately, a 4130 pre-hardened steel bedplate (like the one we designed for the 7.3L) wouldn't add any rigidity to THAT part of the 6.4L block.

I will probably end up filling my 6.4L block...and as long as there is @ 2" of coolant circulating in the top of the water jackets...I don't anticipate any cooling issues, even for daily use.

same chit..different day (different engine platform )...

 

[Fast-6.0]

Start with a new block for $2500. Save the $1200 or so you would have in machining the old block, have a better foundation and peice of mind.

What tells you a new block won't crack? International's machining tolerances are sub par. I would rather have used block that has never had studs and machine it to a tighter spec.

 

[SEABEE08FX4]

Not saying what you are doing is wrong at all but I do have a little more insight based on your comments.

The ARP and A1 studs don't bottom out in the bottom of the blindhole, they stop at the top of the deck. So I don't see this issue as installer error. Nor do I see the 1/2 turn or 1/4 turn backed off doing anything to help or hurt this. The stud turns to bottom itself once torqued, and again it (both brands) stops when the threads at the top of the deck bottom out on the stud. A great distance from where the crack is occuring.

Just some thoughts.

I hear what your saying however even if the threads on the stud bottom out before the stud its self bottoms out in the block, applying more force to it is going to make it want dig deeper into the block. And maybe thats where the crack is coming from, by wedging the stud hole in the block open ( or displacing it ) more. The studs are a lot harder than the block, forcing it more when there is no room to give will just find the next weakest link. I've personally never seen a cracked one myself so I'm not saying your wrong, just coming at it from a different angle.

 

[Lassie]

Is it possible the studs are being made too long for the 6.4 block????

 

[Morgan@Midwest Diesel & Auto]

What tells you a new block won't crack? International's machining tolerances are sub par. I would rather have used block that has never had studs and machine it to a tighter spec.

Nothing tells me it won't crack. What if you had a block with studs already? And why wouldn't having a Block that can accept standard pistons, standard deck height and has never had anyone else's mistakes done to it be bad? I was referring to if you had a cracked block or a previously studded block for this to be alternative since they are relatively cheap and easily attainable.

And for stock rebuilding purposes other than the obvious measuring clearances and checking bores etc, why wouldn't it be more than adequate?

For someone's 900hp drag truck no I would probably re machine with a torque plate and better deck surface and check the line hone.