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can't spell shazam w/o it
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Discussion Starter · #1 ·
Hey, I searched... Couldn't find any benefits to using studs over bolts, or the other way around.

I put in ARP Bolts after I changed my headgasket, and even after using a 14mm 12-point socket, 3 of the ARP bolts have stripped and the socket spins freely over them. It'll hold to a point... then just spins around the bolt. Sweet, and with less than 3,000 miles on them :rolleyes: .

I'm not worried about it, the machine shop can take it out and ditch the head.

I have to get new bolts, or even studs, either way, I'm not putting these back in.

Do you guys reccomend studs or bolts? How do you go about torquing the studs into the block? Do they torque themselves in after you put the head on, along with the nuts?

Thanks for any help.
 

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Both are good. People say that the studs torque more evenly, and they are right. You don't have to worry about false torque readings the stud will already be threaded in the block when you torque it down. But some say they are a pain because it's near impossible to take the head off with them. However I think the new studs have a hex pattern on the top to thread them in with the head in place solving this problem, maybe some one who knows for sure will chime in. Never heard of them stripping.
 

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Yah my new head stud kit is capable of being unscrewed with an allen tool. Much easier to take the head off in the car this way :bigthumb:

And yah the only difference bolt vs stud is torque read quality...they are the same thing otherwise
 

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I've been here forever.
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I have studs on my motor. You have to undo the transmission mount and tip the motor forward in order to take the head off but it can be done. Also, if you do it the right way the first time...dont worry about taking the head off again!
 

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Madd Tyte JDM yo ®
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studs ARE far superior to bolts... there is no 2 ways about it.

bolts put stress on the threads as they turn into the block. the more you tighten the bolts, the more they put torsional and vertical stress on the block threads. not to mention that not all the block threads are engaged when you begin to torque down the bolts. so when you tighten down the bolts, you may have 10 threads engaged, but when you have studs, every single thread in the block is engaged before you ever start to torque down the nut onto the stud.

i hope i was clear enough w/ all that to get my point across.

not to mention, the new studs use a 4mm or 5mm allan key to install, no double-nuttery required. if you plan on doing studs, get a deep socket for the 3/8" drive, not 1/2". every single time someone installs studs for the first time, they buy the socket for the 1/2" drive, then they find out that socket wont fit down between the valve springs. then they have to make another trip to get the right socket.
 
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Sometimes I see dead ppl
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flubyux2 said:
studs ARE far superior to bolts... there is no 2 ways about it.

bolts put stress on the threads as they turn into the block. the more you tighten the bolts, the more they put torsional and vertical stress on the block threads. not to mention that not all the block threads are engaged when you begin to torque down the bolts. so when you tighten down the bolts, you may have 10 threads engaged, but when you have studs, every single thread in the block is engaged before you ever start to torque down the nut onto the stud.

i hope i was clear enough w/ all that to get my point across.

not to mention, the new studs use a 4mm or 5mm allan key to install, no double-nuttery required. if you plan on doing studs, get a deep socket for the 3/8" drive, not 1/2". every single time someone installs studs for the first time, they buy the socket for the 1/2" drive, then they find out that socket wont fit down between the valve springs. then they have to make another trip to get the right socket.
Agreed. I have the experience of have ran both. I bought my 1st mk3 with bolts. needless to say, the bolts will require re-torquing a few hundred miles after installing-I didn't know this, and about 500 miles into a rebuild, I was changing the headgasket.

As far as the studs go. 75ft lbs of torque on a stud is comparable to over 100 I believe. Studs are far superior. go with the studs.
 

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can't spell shazam w/o it
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Discussion Starter · #7 ·
Alright, thanks alot guys. I will definetely be going with ARP Studs then. As for why I'm taking my head off so soon, I'm going NA-T, with all built internals. But again, thanks all.
 

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Studs are better but not really needed. It makes taking the head off with the motor in the car a PITA. Good headgasket on a straight head and arp bolts will suffice.
 

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I wish they had designed the studs so a allen key could be used from the beginning....had to pull head (cracked) with studs already in and spent 8 hours grinding a nut to almost nothing so could place over a regular nut & pull the studs...took care of that by grinding a groove in the top of the studs for a screwdriver for future needs but what a PITA...ok I'm done :)
 

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Matthew 6:33
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jz_killa_t68 said:
Agreed. I have the experience of have ran both. I bought my 1st mk3 with bolts. needless to say, the bolts will require re-torquing a few hundred miles after installing-I didn't know this, and about 500 miles into a rebuild, I was changing the headgasket.
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So the studs do not require a re-torque at all?
 

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from what I have experienced, no. it's harder for them to vibrate loose like the bolts do. I also threadlocked mine with the blue stuff to be safe.
 

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Be careful with the allen fittings on the studs, they are not very good if you happen to set your studs in loctite... LOL, and my using a slightly worn allen socket was a bad idea to start with.
Ended up pulling the stud with a bolt removal tool. (Reverse thread deal that is used to remove stripped or broken bolts after you drill out a hole.. Use the allen wrench hole, and your fine. The stud can still be used again, no worries.)

I just switched over to studs for the mains, and I've used studs for the head for years. The mains require two bolts in the location where the oil pump inlet pipe is, and where the inlet pipe support is. (So you end up with two caps that have one stud, and one bolt.) Tourqe is 85lbs for the mains, and I'm going to 105 on the head side. Pauter rods were tourqed to 65lbs. (ARP type cap bolts that thread into the rods, lubed with ARP moly lube etc. They don't say ARP, but are rated to 220k psi. The studs are all 190k psi rated.) Should never have a fastener fail on this motor I hope.
 

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eh, i'd start to worry about bumping the plastic region of the bolts at elevated operating temperatures with the 105 lb-ft torque I could be wrong however, what are the installation specs for the studs?

adam
 

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Madd Tyte JDM yo ®
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greg, i did my ARP studs to 105 ft/lb WITH the moly lube. i was putting so much torque on the studs w/ the moly lube, it felt like i was about to break them. ARP specifies somethng like 75 ft/lb for studs with the use of moly lube. and their torque ratings are based off fastener stretch for that specific diameter and material... not per application. a 10mm stud is a 10mm stud to them, regardless of application. i think next time, ill torque the studs to 90 ft/lb.

studs are necessary if you want to do anything more than stock.

i would recommend agaisnt loc-tite on when installing the studs into the block... cuz itll take more torque to remove than a 4mm allen key can withstand... as many unfortunate owners have experneinced.

ive actually had someone tell me that they stripped out the allan key trying to undo the "bolts" and that they couldnt get the Head off...
 

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flubyux2 said:
greg, i did my ARP studs to 105 ft/lb WITH the moly lube. i was putting so much torque on the studs w/ the moly lube, it felt like i was about to break them. ARP specifies somethng like 75 ft/lb for studs with the use of moly lube. and their torque ratings are based off fastener stretch for that specific diameter and material... not per application. a 10mm stud is a 10mm stud to them, regardless of application. i think next time, ill torque the studs to 90 ft/lb.

studs are necessary if you want to do anything more than stock.

i would recommend agaisnt loc-tite on when installing the studs into the block... cuz itll take more torque to remove than a 4mm allen key can withstand... as many unfortunate owners have experneinced.

ive actually had someone tell me that they stripped out the allan key trying to undo the "bolts" and that they couldnt get the Head off...

it even says on the arps website and on the instructions for installing the studs... HAND FUCKING TIGHT...well maybe not the fucking part... ;) but hand tight are most definitley there....

studs win....bolts suck...the end
 

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flubyux2 said:
greg, i did my ARP studs to 105 ft/lb WITH the moly lube. i was putting so much torque on the studs w/ the moly lube, it felt like i was about to break them. ARP specifies somethng like 75 ft/lb for studs with the use of moly lube. and their torque ratings are based off fastener stretch for that specific diameter and material... not per application. a 10mm stud is a 10mm stud to them, regardless of application. i think next time, ill torque the studs to 90 ft/lb.

studs are necessary if you want to do anything more than stock.

i would recommend agaisnt loc-tite on when installing the studs into the block... cuz itll take more torque to remove than a 4mm allen key can withstand... as many unfortunate owners have experneinced.

ive actually had someone tell me that they stripped out the allan key trying to undo the "bolts" and that they couldnt get the Head off...
Whoa, 105ft lbs?? If they specify 75ft/lbs why wouldn't you use that? They sheet that comes with the studs has different specs for aluminum and iron heads. They give you a specific torque rating so you dont stretch the bolt too far and make it useless. If you torque it to 105lbs, you may be getting the same clamping load as you would with 75-90lbs, but you may have permently strechted the bolt or stud. I think a lot of people assume by cranking extra torque on the bolt or stud, that it will give more clamping load, and this is not true at all.
 

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Madd Tyte JDM yo ®
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cuz im crazy like dat... they call me Rubba neck!
 

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flubyux2 said:
studs ARE far superior to bolts

not to mention that not all the block threads are engaged when you begin to torque down the bolts. so when you tighten down the bolts, you may have 10 threads engaged, but when you have studs, every single thread in the block is engaged before you ever start to torque down the nut onto the stud.
Studs might be better than bolts but not for this reason. This is incorrect.
If the thread on the bolt is lets say 20mm long (i dont remember the exact number) , the hole in the block for the bolt is slightly longer than that (lets say 25mm), and when you begin tightening the bolt, it's thread sits approximately in the middle of the hole in the block, being a few mm from the top and a few mm from the bottom of the hole. This would mean that when you tighten a head bolt, ALL of it's threads are engaged all of the time.

Dennis

Edit: Can someone please explain to me what would make a head bolt "vibrate out of the thread in the block" and lose it's torque during the first 500miles on the engine, that wouldnt make it "unbolt" AFTER the 500miles. I had a nice discussion about this with my engine builder and we came to a conclusion that this is BS also, and the reason why you need to retorque the bolts is that the head gasket gets slightly compressed overtime with so much pressure from the head, and the bolts will loose a little torque. This concept also applies to studs, so in theory you'd need to retorque them also. In reality the MHG compression factor is minimal after you torque it down for the first time, and most of the time you can get away with just torqueing the bolts/studs 3-5 pounds more than you want the value to be, to compensate for the possible torque loss do to MHG compression. Composite HG's is a different story.

To sum this up, the only REAL reason why studs are better than bolts (as far as im concerned) is what was mentioned above - torque readings will be SLIGHTLY more accurate with the studs. Should this be a concern for 99.9% of Supra owners out there? No...

Feel free to correct me if im wrong.
 
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