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Thread: Headstud comparison

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Posts: 41-50 of 215
2008-03-28 20:02:28
#41
Originally Posted by Katana200sx
if studs are not meant to bottom out, why do the AEBS and greddy have a "dowel" tip that touches the bottom?


The short answer is: Because they assume the people installing them will know not to bottom them out, but they'd like to have as much thread as possible in the block. ARP makes sure you won't bottom them out, and decided less thread in the block was a good trade-off.
2008-03-28 20:07:50
#42
pesonally i am running the ARP with no problems, i think that there is too much hype ovr ARP being ''flawed'' i know im no the only one running ap and i know there are others running arp with even more power than me with no problems. like ben said so much misinformed info going around naming arp as a flawed headstud Mfg
2008-03-28 20:16:17
#43
Originally Posted by GT2871RBLUBIRD
pesonally i am running the ARP with no problems, i think that there is too much hype ovr ARP being ''flawed'' i know im no the only one running ap and i know there are others running arp with even more power than me with no problems. like ben said so much misinformed info going around naming arp as a flawed headstud Mfg


^I was thinking the same thing........I was like, dang there are TONS of people making over 400WHP running these headstuds with NO PROBLEMS....Some of this may be human error.......
2008-03-28 21:23:08
#44
When you bottom out a stud you've pre-loaded the top of the threads in the block with stress. You then tighten the nut at the top, producing even more stress on the top of the threads in the block.


do you notice how much thread the greddy has over the arp? do you understand that the opposite of what you described above is happeneing? we are lifting heads because there is only like three threads in the block that are under the "stress" factor that you talk about. why? becasue that damn buldge at the top on the threads will not it let go down anyfarther. what they should have done was under cut the shank of the stud, and leghtened the threads..... which is what exactly cosworth, greddy, and tomei has done.

we are lifting heads at around 500whp. no melted pistons, no blown headgaskets. just lifted heads.

o.k. hears a clarification. if you are going to stay under lets say 420whp, then do arp. if you go above then get something better. just my opinion.
2008-03-28 21:34:14
#45
Originally Posted by LANCESR20
do you notice how much thread the greddy has over the arp? do you understand that the opposite of what you described above is happeneing? we are lifting heads because there is only like three threads in the block that are under the "stress" factor that you talk about. why? becasue that damn buldge at the top on the threads will not it let go down anyfarther. what they should have done was under cut the shank of the stud, and leghtened the threads..... which is what exactly cosworth, greddy, and tomei has done.

we are lifting heads at around 500whp. no melted pistons, no blown headgaskets. just lifted heads.

o.k. hears a clarification. if you are going to stay under lets say 420whp, then do arp. if you go above then get something better. just my opinion.



Dam Lance you beat me to it. The buldge you talk of is on the top of the stud not the bottom. With the better studs you don't tighten the stud hard in the block just like the arps. The greddy's also are made of better material then the arps are also.

Just as Lance say head lift with ARPs happens around 500hp. You can run arps that high but sooner or later you will lift the head and maybe rip the threads out of the block maybe. So you have to pay to play is all I have to say.

Matt
2008-03-29 02:35:47
#46
Yeah, you have to pay to play, but you also have to cause yourself undue stress trying to find a set of headstuds that's IN STOCK, on the shelf.
2008-03-29 04:30:48
#47
Originally Posted by MR-4Door-SR20DE
^I was thinking the same thing........I was like, dang there are TONS of people making over 400WHP running these headstuds with NO PROBLEMS....Some of this may be human error.......


exactly, there is human rror is everything and IF there are cases of stud problems that are human related and then directly corralated to the studs failing, its a quick way to come to a faulty conclusion. i dont care im running arp, there are like you said a ton of ppl making more than 400whp more than 500whp more than 600 with them.. too many variables to take into consideration
2008-03-29 05:44:47
#48
How about this... BOOST is the issue here, not WHP. Sure, the whp is derived from BOOST, but a car can push 30+ psi of boost and still only make 380whp.

Would you feel comfortable forcing say...32PSI of boost into the motor, even though you're only making 450whp? KNOWING that the ARP headstuds have been proven to fail from fatigue?

Again, I'm not knocking ARP here, they make a good product. I just don't want to throw high levels of boost and have the head lift like some VE owners have had happen. It just doesn't make sense to ignore their documentation, and continue to use ARP headstuds that haven't been redesigned.

Now, please show me the TON of people making more than 400whp, 500whp, etc. that are using ARP headstuds, and at boost higher than say 20psi.
2008-03-29 08:26:02
#49
Originally Posted by LANCESR20
we are lifting heads because there is only like three threads in the block that are under the "stress" factor that you talk about.



Are the heads lifting and returning (as the BMW guys get with stock head bolts) with no damage other than water/oil everywhere? Or are the heads lifting off, and the head studs ripping out of the block?
Once again, I've come into this conversation very late, and with limited background information, which is why I have these questions.
If the heads are lifting and returning, you have a problem with tensile strength of the stud (obviously) and not a problem with threaded depth as you state.

If the head studs are ripping out of the block, you've certainly got a point about the thread depth being a problem.
2008-03-29 10:14:32
#50
Originally Posted by BenFenner
Are the heads lifting and returning (as the BMW guys get with stock head bolts) with no damage other than water/oil everywhere? Or are the heads lifting off, and the head studs ripping out of the block?
Once again, I've come into this conversation very late, and with limited background information, which is why I have these questions.
If the heads are lifting and returning, you have a problem with tensile strength of the stud (obviously) and not a problem with threaded depth as you state.

If the head studs are ripping out of the block, you've certainly got a point about the thread depth being a problem.



i believe over the years i have read accounts of both. someone correct me please if i am wrong.
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