What boost pressures will Arp studs hold with out O-ringing the head for now?

[ASTAR]

Man, I am in the same boat! I can't afford the o-ring right now but I could do the studs. I push my boost psi up to 55ish from time to time (short bursts) and I have the stock HG so it worries me a lot. I also would LOVE to know if the studs would help till I could o-ring.

 

[Hohn]

OK, some explain to me how a 160KSI factory bolt holds "just as well" as a 220KSI ARP stud

Clamping force doesn't matter?

Anyone? Beuhler?

 

[rivercat]

ASTAR I would run what you got now just be real careful with the water. what are m3s like?

 

[Turbo Thom]

My point is, a stock head gasket with a stock head is just that. Stock. No 0 ring, and the bolts will hold what the stock gasket will take. 125 lbs torque on the bolts, is all the same, no matter what you have in the block for retainers. Bolts, studs, c-clamps, whetever you use. We have had boost is the 40lb range blow gaskets, but the timing, a flat head, and torque is the issue here. The stock bolts have proved to hold up to high boost when torque properly. I just wasted the head gasket on my 3500. I replaced it with the stock one. Boost never gets over 36 lbs. Timing blew that one. I have the HX 35 with a 14 housing. EGT's are never an issue, the timing was to great for the constant torque the engine is under towing 15K lbs.



Let me ask you this. When you have the head O ringed, do you install the stock head gasket? Why, and what would work better? What I'm asking also, is when you say something, is it what you "know" to be, or something you read or was told? Just because the studs are installed, does not mean the head gasket issue is over.



The old saying goes here, "it ain't what I know that concerns me, it's what I know that just ain't so".



I guess I need to bow out and let you folks have a good time.



C' y'all



. . Preston. .

 

[RoadGoesOnForever]

125 lbs torque on the bolts, is all the same, no matter what you have in the block for retainers. Bolts, studs, c-clamps, whetever you use.

I disagree with this statement. The stock bolts will deform a little bit more than the studs each time the cylinder fires. If the cylinder pressure is high enough, the head lifts off the block and the gasket blows. Since the studs have much more tensile strength, they do a better job of keeping the head firmly affixed to the block.

 

[Jetpilot]

Its not boost pressure that blows headgaskets, its cylinder pressure. There are numerous components that go into cylinder pressure and boost is just a small percentage of it. Why do you think the 12v trucks blow headgaskets with advanced timing and no additional boost? Turbo's, cams, pistons, wastegates, cams, injection events all have an effect on cylinder pressure.....



I have seen HG's blown trucks with low boost while others have run very high levels of boost on the OEM gasket with bolts or studs and done fine. It is more important to setup the engine correct for the mods than be concerned about boost pressure. A truck running an HY35 and 40 psi boost is in more danger of popping a HG than the same truck running something like a SPS66 @ 50 psi.



Also remember more boost does not mean more HP, the shop truck makes 600 RWHP @ 45 psi boost.



Doug Smith

 

[Turbo Thom]

Thanks Doug... ... ..... you saved me.



And while the studs are higher tensile strength than the bolts, what caused a block to seperate about 2 inches below the top of the block? Boost? The studs were still in place, as was the head. They were just in the wrong place. When Shelly Keating ran at IRP, he was still on head bolts. Head gaskets were not his problem.



Like I said before, do you say what you hear, or what you know to be so?



. . Preston. .

 

[Hohn]

600hp @ only 45psi is impressive. It points to a good-breathing rig with a good turbo setup.

I think Turbo Thom is overlooking the influence of clamping on HG holding. If you have more clamp on the oem HG, it holds more, plain and simple.

I'm becoming more convinced by the day that the SPS66 is the charger for me.

jh

 

[Fishin Guide]

My point is, a stock head gasket with a stock head is just that. Stock. No 0 ring, and the bolts will hold what the stock gasket will take. 125 lbs torque on the bolts, is all the same, no matter what you have in the block for retainers. Bolts, studs, c-clamps, whetever you use. We have had boost is the 40lb range blow gaskets, but the timing, a flat head, and torque is the issue here. The stock bolts have proved to hold up to high boost when torque properly. I just wasted the head gasket on my 3500. I replaced it with the stock one. Boost never gets over 36 lbs. Timing blew that one. I have the HX 35 with a 14 housing. EGT's are never an issue, the timing was to great for the constant torque the engine is under towing 15K lbs.



Let me ask you this. When you have the head O ringed, do you install the stock head gasket? Why, and what would work better? What I'm asking also, is when you say something, is it what you "know" to be, or something you read or was told? Just because the studs are installed, does not mean the head gasket issue is over.



The old saying goes here, "it ain't what I know that concerns me, it's what I know that just ain't so".



I guess I need to bow out and let you folks have a good time.



C' y'all



. . Preston. .

Interesting thoughts. But I feel you are wrong.



Jetpilot hit the nail on the head. It's cylinder pressure taking out the gaskets. And of course one has to factor drive pressure in that one as well.



Bottom line is stock bolts are easier to stretch further than ARPs. Period. So, all things being equal, adding 10lbs boost to a stock headbolt that may result in failure would most likely hold with ARPs. As these bolts have a higher ability to control the lifying of the head. Also, studs will carry a more accurate torque and you reduce the twisting force over the length of the fastener. That's like a spring by the way.



BTW, mine is holding just fine to well over 60PSI.



Dave

 

[driverno8]

I have a question. And if it sounds stupid I'm sorry. Here goes.



What's worse. That quick spike to 60psi or holding it steady at say 40psi for a few minutes. I would think it would be holding it steady. Am I wrong? Just another thought that I don't know the answer too.

 

[RoadGoesOnForever]

I have a question. And if it sounds stupid I'm sorry. Here goes.



What's worse. That quick spike to 60psi or holding it steady at say 40psi for a few minutes. I would think it would be holding it steady. Am I wrong? Just another thought that I don't know the answer too.

As has been said already, the cylinder pressure is what really matters, not boost, so it depends how close 60 psi was to limits of the head to block joint, but generally a sustained load is worse than a short spike, so I would guess the sustained 40 psi would be worse than a spike to 60 psi all other things being equal (EGT, timing, injection pressure, etc. )

 

[JaMan]

Now this is getting interesting... So would it be better to spend the 4 bills on an o-ring job and gasket and use the stock headbolts for now and replace them with studs later, or studs now and o-ring later?



Jared

 

[Jetpilot]

Now this is getting interesting... So would it be better to spend the 4 bills on an o-ring job and gasket and use the stock headbolts for now and replace them with studs later, or studs now and o-ring later?

O-rings will hold more than studs. I held over 750 RWHP using OEM bolts and O-rings.....

 

[JaMan]

Ok that sounds good...

 

[ASTAR]

O-rings will hold more than studs. I held over 750 RWHP using OEM bolts and O-rings.....

Figures, I just bought studs!

 

[zstroken]

O-rings will hold more than studs. I held over 750 RWHP using OEM bolts and O-rings.....

Not discounting what you said because, but maybe it was because you made sure everything was true(deck the head/block) before it was put back together. So many of the cummins have quite a few miles on them that the head may have a little warp on it, and I am unaware of the specs the factory uses.

 

[Turbo Thom]

Doug... ... ... ... . that's been my point. If you don't 0 ring the head, why waste the money on studs. Anybody that thinks you're going to hold more with a stock head gasket, just because you clamp harder with studs, is a , well, they're just not thinking straight. Now that's not excatly true. More torque on the bolts will hold more. My point is, if you think studs is the cure all for blow headgaskets, without O ringing the head, you are wrong. But that's what make this so interesting. Everybody has their opinion and that causes critical thought. I love it.



What works for me, does just that. May not for you, or your mechanic says I'm full of, but it works for me.



Keep the mind working.



. . Preston. .

 

[Forrest Nearing]

studs will absolutely hold more... not only can you torque them higher, but they will not stretch as much as stock bolts.



I would just do both and be done with it, but it would be easier to just drop studs in... if your'e going to o-ring the head, you might as well just get studs and be done with it

 

[Turbo Thom]

You are right. Studs will hold more. But the gasket has a lower thresehold of pain. The gasket will hold most everything the bolts will, it will not the studs. And you're right again. Do them both, rings and studs and be done with it.



I quit. :-{}



. . Preston. .

 

[Jetpilot]

Guys when I said O-ring's will hold more I didn't want to make anyone think studs are inferior..... Back when we first started doing o-rings in head on our diesel the studs were not available. Hence the reason for the high HP #'s with bolts. The combination of a good o-ring job and studs will hold about anything we can throw at our engines. xstaoken is correct all o-ringed heads I have done start with a good surface so a better seal is apparent.



I have installed studs on trucks and seen the HG blow at relative low boost or cylinder pressure. Personally I feel that o-rings are a great way to ensure reliability, so if its one or the other I would go with o-rings, but again the best is to do both.



Doug