Speed Master Head studs
Joined: Aug 2007
Posts: 24,241
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From: Turnin' Wrenches Infractions: 005
I pulled the threads out of an LS1 head bolt hole presumably from some coolant left in the hole. Had to timesert the hole, which is fine but was a pain. I do headstuds only if for nothing else that reason alone.
Guys have gone 4’s at at 50ish lbs of boost on S500 frame turbos with the cheap studs in a 5.3. That’s like 1400+hp in a 3000lb chassis.
Most that have problems when they over torque them on install and snap them. It’s the quality control from fastener to fastener that make the china studs a crap shoot. One may torque to 70ftlbs fine and another may break there. IMO if you use them buy 2 sets. That way if one breaks you aren’t waiting weeks on another set. Also treat them as a TTY fastener and don’t reuse them. Especially if you go over 65ftlbs on the final assembly torque like most do. Which they aren’t rated for. Over torqueing a fastener and over stretching it will lessen the clamping force. So you aren’t doing yourself any favors torqueing these to 75-80ftlbs like many do, even if they don’t snap. I ran 25-26 lbs on them torqued to 65ft lbs. Pushing roughly 900hp.
Most that have problems when they over torque them on install and snap them. It’s the quality control from fastener to fastener that make the china studs a crap shoot. One may torque to 70ftlbs fine and another may break there. IMO if you use them buy 2 sets. That way if one breaks you aren’t waiting weeks on another set. Also treat them as a TTY fastener and don’t reuse them. Especially if you go over 65ftlbs on the final assembly torque like most do. Which they aren’t rated for. Over torqueing a fastener and over stretching it will lessen the clamping force. So you aren’t doing yourself any favors torqueing these to 75-80ftlbs like many do, even if they don’t snap. I ran 25-26 lbs on them torqued to 65ft lbs. Pushing roughly 900hp.
Am I missing something here?
TECH Senior Member
Joined: Jun 2016
Posts: 22,308
Likes: 3,624
From: Central Cal.
There was a post recently (don't remember where it is) where someone tested the tensile strength of OEM TTY bolts, chinese bolts, ARP bolts and ARP studs.
The OEM TTY bolts had a higher tensile strength than the chinese studs did.
I like the studs for many reasons, but it's been proven many times that the OEM style will take a lot more than most think they will.
The OEM TTY bolts had a higher tensile strength than the chinese studs did.
I like the studs for many reasons, but it's been proven many times that the OEM style will take a lot more than most think they will.
Thought I don’t claim to be an expert in anyway, I’ve personally pulled apart 10-20 LS engines and have never seen threads pulled out of a block. Not that it can’t happen, but I don’t believe it happens “very often” as we would see/read about it on here if it was common.
IMO. If others have pushed the OEM bolt to “X” HP successfully, you can’t argue that fastener is not suitable for an application making less than half that HP?
Experience trumps all theory/opinion.
We have seen the same set of used TTY bolt used 3-4 times in a row on the same block making over 900-1000whp. This engine was pulled apart multiple times due to failures/issues not related to head gaskets. There was never an issue with the head gasket seal. All was documented and filmed, including the tear down, rebuilds, and torque procedure. And that’s only once instance. The same person has built and tuned multiple 500-700 whp turbo LS setups reusing OEM bolts with no reports of head sealing issues.
Look at the sloppy mechanics wiki page and you tube page. It beyond a doubt proves the OEM bolt is more than enough for 99% of the NA builds out there IMO. The cylinder pressure just isn’t there to need more clamping load than the OEM bolt provides in a typical NA application, or mild boosted application. Hell, even in pretty radical boosted applications they appear to hold up fine.
IMO. If others have pushed the OEM bolt to “X” HP successfully, you can’t argue that fastener is not suitable for an application making less than half that HP?
Experience trumps all theory/opinion.
We have seen the same set of used TTY bolt used 3-4 times in a row on the same block making over 900-1000whp. This engine was pulled apart multiple times due to failures/issues not related to head gaskets. There was never an issue with the head gasket seal. All was documented and filmed, including the tear down, rebuilds, and torque procedure. And that’s only once instance. The same person has built and tuned multiple 500-700 whp turbo LS setups reusing OEM bolts with no reports of head sealing issues.
Look at the sloppy mechanics wiki page and you tube page. It beyond a doubt proves the OEM bolt is more than enough for 99% of the NA builds out there IMO. The cylinder pressure just isn’t there to need more clamping load than the OEM bolt provides in a typical NA application, or mild boosted application. Hell, even in pretty radical boosted applications they appear to hold up fine.
And like I posted above, your position on the OEM TTY bolts has been proven with tensile strength tests, they are stronger than the chinese studs and very close to the ARP bolt.
However, they are TTY so I would never recommend reusing them, it is interesting what they are capable of though, even when re used.
Here is one of the test threads but it's not the one I was mentioning that tested the ARP bolts, here they tested the ARP studs
https://ls1tech.com/forums/generatio...ngth-test.html
TECH Senior Member
Joined: Jun 2016
Posts: 22,308
Likes: 3,624
From: Central Cal.
Yeah, I don't have a problem with TTY bolt's quality, it's just that they are not SUPPOSED to be used more than once. I guess it's my Dutch thriftiness rearing its head. To me, quality reusable trumps quality disposable.
Depends. I think the fact that the OEM bolt is tightened to an angle value instead of a torque value is of significance. There's a better chance that the bolts will be will all apply a more consistent load using an angle value compared to a torque value used by ARP.
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Verdad Gallardo TECH Senior Member
Joined: Jun 2016
Posts: 22,308
Likes: 3,624
From: Central Cal.
Good points, but could using tightening to angle be applied to reusable hardware? I like your reasoning on the torque to angle method, but still also like to be able to reuse the bolts. Forgive me if too much ignorance is showing here lol.
But by then, you've probably spent enough time and money to justify a couple sets of OEM bolts instead anyways.
I wonder, since ARP isn't stretching the bolt, does it need to be pushed on a little (slight head lift) to get into the strength of the bolt that is stronger than the OEM bolt. In other words, I wonder if the initial clamp force of the OEM is higher than the clamp of the ARP since the bolt is tightened right into "yeild". This may sound real strange, i'm not very far into my first cup of coffee.
We see that the ARP has higher tensile strength, but being that you pointed out that the OEM is likely to have a more consistent load and I agree, it made me think of the initial sealing of the gasket and if the ARP is better at anything than just resisting stretch. Which if the cards fall the way they I think they may, we may theorize that the OEM will actually stave off initial gasket failure a little better but the ARP may keep it from lifting as far...? I've gone way too far with this now.
Restricted User
Joined: Mar 2014
Posts: 7,192
Likes: 109
From: Ohio
I've used re-used stock head bolts or Chinese studs on everything from Single turbo, twin turbo, quad turbo, small N/A cam, big N/A cam, nitrous, iron or aluminum block, and whatever other crap I've done.
I've still never so much a stripped a thread or blown an OEM headgasket.
I've still never so much a stripped a thread or blown an OEM headgasket.
Restricted User
Joined: Mar 2014
Posts: 7,192
Likes: 109
From: Ohio
If you want, I can show you pictures of snapped ARP studs, or ARP nuts that were never machined or threaded. To say that they're going to be perfect is a pipe dream. ARP studs break too, and it wouldn't take anyone long to find proof.
I have a few of those broken ARP's as well, one bolt and one stud. I will say ARP was very good about replacing them. But its all china for me now, I ordered and extra set to have on hand to steal a stud from if I break one.
ARP Stud Tech 101 Hi Floader, I bought 20 ARP studs with nuts for a Ford Coyote, a PERFECT fit for an my customers 5.7 SC Toyota engine assembly.
I have a Hardinge "collet" lathe that I used to "under-cut" the ARP's for correct stretch.
WHAT I FOUND : Ten studs ran "true" with ten Out of Round.
My conclusion was that these studs where not "American MADE" quality.
It WAS REQUIRED to "clean" the stud threads on three as the NUTS would NOT hand tighten, then NOT even in a Vice.
THUS My REPORT of ARP quality.
Lance
I have a Hardinge "collet" lathe that I used to "under-cut" the ARP's for correct stretch.
WHAT I FOUND : Ten studs ran "true" with ten Out of Round.
My conclusion was that these studs where not "American MADE" quality.
It WAS REQUIRED to "clean" the stud threads on three as the NUTS would NOT hand tighten, then NOT even in a Vice.
THUS My REPORT of ARP quality.
Lance
I wonder if ARP has changed manufacturers over the years, I haven't put a set of ARP studs in in many years, the recent motors I have done were ARP bolts or OEM (customer choice not mine, not that I have a problem with it but I prefer studs), but many years ago I put several sets of studs in and all threaded very nicely and everything looked perfect. I didn't measure for out of round or anything, just noting I had zero threading issues.
ARP manufacturers their products in-house in California.
While I've never checked any ARP bolt for runout, I've never had a problem with any of their stuff. Threads have always been perfect and clean, nuts spin on freely.
While I've never checked any ARP bolt for runout, I've never had a problem with any of their stuff. Threads have always been perfect and clean, nuts spin on freely.