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ARP stud stripped my block threads

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LeeRichmond

20+ Year Contributor
45
0
Nov 1, 2002
Kelowna, B.C._Canada
well while installing my cometic headgasket and arp head studs one of the studs stripped my block threads and I didnt even have an extension on my 1/2" drive socket probably about 60ftlbs worth of pressure. Why would this have happend? whats the easiest fix? thanks guys.
 
threaded all the way in to a clean threaded hole 3/16th allen key to tighten it.
 
I never tighten my studs. Hand tight to the clean bottom is what is suggested.
 
TimG said:
I never tighten my studs. Hand tight to the clean bottom is what is suggested.


That's how I did mine as well, just hand tight with some lock tite.
 
so you think by snugging up the stud it caused what sort of problem?
 
snugging up the stud would make no difference as it is being pulled in the opposite direction. Would a helicoil hold up to 80ftlbs?
 
That's how I did mine as well, just hand tight with some lock tite.

just to add, if using loctite you must torque them before it cures.

60ftlbs worth of pressure

im having trouble believing that it was actually 60FT lbs, either the threads were damaged and/or not cleaned/preped properly or your torque wrench is wayyyy off..

either way that really sucks.. have you tried running a tap thru the threads to see if it clears it up at all? or is it completely ruined? i dont think i would trust a helicoil.
 
Im not sure about people with ARP head studs, but I pulled my head off a few times, and everytime I just sprung for new OEM head bolts so I could have piece of mind that they were'nt comprimized, this is just how I do things I would rather spend the little bit more to save in the long run. Also make sure not dirt or any junk gets inside the threads so I used brake clean, then a small hose hooked up a shop vac to get anything that built up at the bottom. Also as for the ARPs TQ specs. ARP recommends TQing them down to 75ft/lb with their moly lube, and according to Dan(project tsi) if you use reg. oil as a lube TQ them to 90ft/lb. What you should do after putting them in hand tight it set the TQ wrench at 30ft/lbs, then tighten, then set to 60ft/lbs, then tighten, then set to 90ft/lbs. You can set the max from anywhere from 75ft/lbs to 90ft/lbs. Make sure you check the TQ specs and re-tighten them after the first heat cycle. The pic shows the route of properly tightening head studs.

Dustin
 

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actually the threads are in ok shape and still snug up the stud but slip when enough torque is applied. I am helicoiling the block this is going to be strong enough and Im now going with a stock headgasket since they seal better and dont have to worry about it. and it did shock me when it partially stripped because I wasnt torquing that hard.
 
According to the shop manual:

For Bolt Installation:
1) When installing the cylinder head-bolts, the length below the head of the bolts should be within the limit. If it is outside the limit, replace the bolts. Limit (A): 99.4 mm (3.91 in.)
2) Apply engine oil to the bolt thread and the washer.

For Tightening the bolts:
1) Tighten to 58 ft. lbs. In the order as shown in the diagram
2) Loosen Fully. In reverse order as shown in the diagram
3) Tighten to 15 ft. lbs. In the order as shown in the diagram
4) Tighten 90 degrees of a turn. In the order as shown in the diagram. Mark the head of the cylinder head bolt and cyclinder head with paint to show your angle.
5) Tighten 90 degrees of a turn. In the order as shown in the diagram. Check that the painted mark of the head bolt is lined up 180 degrees of the painted mark on cylinder head.

And it cautions:
1) Always make a tightening angle just 90 degrees. If it is less than 90 degrees, the head bolt will be loosened.
2) If it is more than 90 degrees, remove the head bold and repeat the procedure from step 1.
 

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Splitpi said:
According to the shop manual:

For Bolt Installation:
1) When installing the cylinder head-bolts, the length below the head of the bolts should be within the limit. If it is outside the limit, replace the bolts. Limit (A): 99.4 mm (3.91 in.)
2) Apply engine oil to the bolt thread and the washer.

For Tightening the bolts:
1) Tighten to 58 ft. lbs. In the order as shown in the diagram
2) Loosen Fully. In reverse order as shown in the diagram
3) Tighten to 15 ft. lbs. In the order as shown in the diagram
4) Tighten 90 degrees of a turn. In the order as shown in the diagram. Mark the head of the cylinder head bolt and cyclinder head with paint to show your angle.
5) Tighten 90 degrees of a turn. In the order as shown in the diagram. Check that the painted mark of the head bolt is lined up 180 degrees of the painted mark on cylinder head.

And it cautions:
1) Always make a tightening angle just 90 degrees. If it is less than 90 degrees, the head bolt will be loosened.
2) If it is more than 90 degrees, remove the head bold and repeat the procedure from step 1.

ARP specifically states, while you do follow the factory torque sequence DO NOT use the factory torque specs, use ARP's. Are you 100% sure the block is stripped? When I was torqueing mine I had one nut that wouldn't torque when I got to my last torque reading, it would just start to spin. When I installed the studs I bottomed them out with an allen key then backed them off 1/8" or so. With this method I tried twice with the same result, so I tried a third time and didn't back the stud off quite as much and it torqued fine.
 
the threads loooked to be in good shape but I tried a different bolt before moving the head and it slipped when torqued as well so I didnt want to risk it and helicoiled it and it fit much more snug to the stud then the original threads.
 
arp studs didnt fit properly. not sure why but anyways the stock head bolts worked 100000x better.
 
You might've had the wrong studs, as aero said. The 6-bolt and 7-bolt ones are different sized. And to add to what daren was saying, ARP suggests doing a 3-stage torquing spec-ing, not like the stock bolt specs. I did mine in the stock sequence, first to 30ft/lbs, then started at the beginning doing 60, then I finished off with 90. Then about 1000 miles later, I rechecked torque, and only 2 or 3 turned at all. The rest were still at 90ft/lbs.

When putting the studs in the block, after the holes were thoroughly cleaned, I hand tightened them with the allen. I then backed it up about a full turn. I used Permatex high temp. thread sealer for the studs. Then, once I put the head on, the nuts all went on fine and torqued down fine.

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I stripped the same bolts and i even retapped them once... i hit a bump really hard and the top bolts from the exhaust manifold connecting to the head just ripped the bolts out. Is it possible the aluminum head is just to old and soft or something? I thihnk ill try that thread sealant stuff
 
We're talking about the ARP head studs that hold the head to the block. The exhaust manifold studs are very brittle, and it's a common occurance to break them. The thread sealant is necessary for the studs that hold the head to the block because the bottom of some of the studs protrude into the oil galley. When doing exhaust manifold studs, don't use thread sealer. Instead, use anti-seize.
 
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