Cracked blocks

[makaveli200369]

You're welcome. I'm going to torque mine down the way Morgan suggests. I had my entire engine heat and cryo treated I can only hope the grain realignment will hold up.

Stroker221 unfortunately these fools only threaded the bottom of bolt hole. The thread length in the block hole is only a tad longer then the thread length on ARP. The remaining material from the top deck down to where the thread starts in the hole is WIDER then the threads so you can't tap it to add additional threads. Bastards! If they just started tapping the towards top there would be more meat in the hole.

Does anyone have a picture of a block that is cracked?

 

[SEABEE08FX4]

For whats its worth we don't torque them to 275 either due to the issues with casting line cracks. They hold just fine at lower spec's.

 

[makaveli200369]

For whats its worth we don't torque them to 275 either due to the issues with casting line cracks. They hold just fine at lower spec's.

What are you torquing them at? All at 250? or 225 for the weak holes and 250 for the rest? Thanks

 

[SEABEE08FX4]

Depends 230-250 but same for all studs. Just depends on the shape of the block.

 

[makaveli200369]

Thanks for the info

 

[stroker221]

Ok thanks for clearing that up makaveli. Why did they think they needed to make the holes so deep!

 

[Morgan@Midwest Diesel & Auto]

250 max and if you need more sealing capacity use o-rings.


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[BigBluediesel08]

Truck is going in for head gaskets cause the 2nd time they retorqued them, it puked( maybe it needed a bit more torque).. I'm going to use new studs this time.. Should I be worried with the block cracking being that it'll be the 3rd time in?

 

[SEABEE08FX4]

250 max and if you need more sealing capacity use o-rings.


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Agreed, they're honestly a huge stud so I don't see them needing to go all the way to 275 to hold just as much at say 230.

 

[madman1234509]

Morgan, could torquing them to 250 be the reason you've seen puking over 70psi boost or back pressure like you mentioned in another thread? Which gave cause for you to feel heads should be o-ringed if the truck is planned to see more than that? I know several people probably see more than that at the instructed torque with No issues puking. Just curious if you think it all goes hand in hand.... Not that it's a bad thing. Probably less risky doing it your way with o rings and less torque, especially for a decent sized shop that pumps them out all the time, less chance of cracking a customers block.

 

[Morgan@Midwest Diesel & Auto]

Morgan, could torquing them to 250 be the reason you've seen puking over 70psi boost or back pressure like you mentioned in another thread? Which gave cause for you to feel heads should be o-ringed if the truck is planned to see more than that? I know several people probably see more than that at the instructed torque with No issues puking. Just curious if you think it all goes hand in hand.... Not that it's a bad thing. Probably less risky doing it your way with o rings and less torque, especially for a decent sized shop that pumps them out all the time, less chance of cracking a customers block.

I've done two here that were over 900 rwhp and high boost. Both were originally torqued to 275. Both pushed coolant. On we resealed and torqued with new H13 studs to their torque, it pushed again. Then we went to o-rings and 250 with arp's. No issue.

And also, these trucks have been pushed to full boost back to back 10 plus times in a row setting gates etc. We do our best to torture test things to make sure the customer doesn't leave and then come back in the next 2 days or 2 weeks because of an issue we missed.

I've had other trucks not puke. The pull truck is torqued to 250 with non factory head gaskets and I've never blown one. But I wouldn't do that to a customers.

In the end, for the cost difference and low chance of failure or cracked blocks, o-rings are a no brainer when your name and warranty are attached to the job.


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[madman1234509]

I hear ya there. I think I've been pretty lucky so far. I'm at 275 with no o rings here. And like you said when setting the gates I'd see back to back high boost numbers on some back roads, which I think attested that it was going to be ok as far as puking under normal conditions. When it comes apart to get built I think it'll definitely get o rings For what its worth. It may need them with the turbo set up I'm planning to put on it.

 

[B585Ford]

I hear ya there. I think I've been pretty lucky so far. I'm at 275 with no o rings here. And like you said when setting the gates I'd see back to back high boost numbers on some back roads, which I think attested that it was going to be ok as far as puking under normal conditions. When it comes apart to get built I think it'll definitely get o rings For what its worth. It may need them with the turbo set up I'm planning to put on it.

This is more of a theoretical question....but I assume you gates were pretty much closed initially when you started to dial them in and then you started opening them earlier as you were tuning it. Leaving timing out of the question....wouldn't high EBP be more likely to cause puking than high boost?

 

[madman1234509]

You're probably right. And I'm not sure where cylinder pressure comes into play with all of it, how how the combined boost/back pressure effect it and which one effects it more. When I started with the gates all the way closed, I'd peg my 100lb back pressure gauge and make about 60-65ish lbs of boost. Now I make about 70-75 and 85lbs of back pressure. I haven't messed with it much since then, and right now it's making that running off of 2 springs and no air.

But regardless, I would see high back pressure, and also high boost at certain times depending on how we had the gates set. I did one run with them set to open almost immediately and right away saw 50lbs out of the low pressure alone, not sure what total boost was.

 

[Sideswipe505]

Are we talking about O ringing the heads?

 

[B585Ford]

You're probably right. And I'm not sure where cylinder pressure comes into play with all of it, how how the combined boost/back pressure effect it and which one effects it more. When I started with the gates all the way closed, I'd peg my 100lb back pressure gauge and make about 60-65ish lbs of boost. Now I make about 70-75 and 85lbs of back pressure. I haven't messed with it much since then, and right now it's making that running off of 2 springs and no air.

But regardless, I would see high back pressure, and also high boost at certain times depending on how we had the gates set. I did one run with them set to open almost immediately and right away saw 50lbs out of the low pressure alone, not sure what total boost was.

Sounds like a pretty good torture test...glad they held.

 

[ckrueg]

I would think cylinder pressure is the biggest contributor in puking. Cylinder pressure is in the 1000s of psi while ebp/boost is under 100 most of the time. ebp is just a result of higher cylinder pressure, more pressure in the cylinder = more pressure out the exhaust

 

[B585Ford]

I would think cylinder pressure is the biggest contributor in puking. Cylinder pressure is in the 1000s of psi while ebp/boost is under 100 most of the time. ebp is just a result of higher cylinder pressure, more pressure in the cylinder = more pressure out the exhaust

Agreed...cylinder pressure is what ultimately leads to failures. Many variables contribute such as piston design, timing, amount of fuel, etc. I guess I should have stated that in this case, does EBP lead to higher cylinder pressures more than boost.

 

[ckrueg]

Agreed...cylinder pressure is what ultimately leads to failures. Many variables contribute such as piston design, timing, amount of fuel, etc. I guess I should have stated that in this case, does EBP lead to higher cylinder pressures more than boost.

I would actually say boost leads to higher cylinder pressure, more air going in would raise the pressure of combustion, where as back pressure is after the combustion happens ie after the cylinder pressure peaks.

 

[Sahrens0202]

Yeah but force is what lifts the head. So take your bore and get the area (3.86 squared=14.8996 X .7854= 11.702). So take 11.702 X the cylinder pressure and you get the force pushing up on the head per cylinder when it fires.