head studs too short??
11-22-2009, 11:16 PM
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head studs too short??
I'm in the middle of installing arp head studs to hold down my new oringed head. I got it all torqued up to 90 ft/lbs, but the short studs along the exhaust side seem too short. The nuts are only half threaded onto these studs while the others studs have a few threads sticking above the nut. I dont want to continue to increase the torque to the recommended 125 ft/lbs with only half the threads engaged. I might get another turn or two out of the nuts by the time I get to 125 then retorque a couple times, but that still wont fully engage the nuts. Anyone else had this problem???
I bottom tapped the 6 long studs that go through the rocker stands so they would clear the valve covers, and I ran a regular tap down the rest of the holes.
I bottom tapped the 6 long studs that go through the rocker stands so they would clear the valve covers, and I ran a regular tap down the rest of the holes.
11-23-2009, 01:39 AM
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are the studs bottomed out? if they are screw them out till there just flush with the nut or even a thread below the nut thats what i did and a few other guys i know also did that im hitting 60lbs of boost daily and havent had a single problem
11-23-2009, 11:17 AM
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Thanks for the suggestions. Thats what I was thinking about doing, but i didn't know if it would effect the clamping force. Sounds like it should be fine. thanks again!
11-23-2009, 02:10 PM
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When you put ARP studs in your truck you're supposed to have your valve pedestal machined down a little bit on that side so the nut goes all the way on to the stud.
11-23-2009, 07:24 PM
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11-23-2009, 07:38 PM
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I'm not being an Ace to you.. But DON'T DO IT!!!!!! Wrong studs. call ARP and tell them of your issue. Good folks. Most likely they will send you the correct ones and pic the postage up both ways.
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11-23-2009, 09:01 PM
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. The rule of thumb I learned from being a machinist for a thousand years is a fastner must engage one bolt diameter to be OK and two bolt diameters to be safer. When a threaded fastner is torqued to proper stretch, the top three threads take 75% of the load and the remainder threads spread the remaining load between them. As time goes on the load eventually spreads out to the rest of the hole but not evenly. Of course it is just a rule of thumb and the material that you are using has a lot to do with the integrity of the threads. In cast iron I would want two diameters of stud engagement as a minimum. The nuts are a heat treated alloy and one diameter of engagement is good.
11-23-2009, 09:14 PM
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Good advice. The rule of thumb I learned from being a machinist for a thousand years is a fastner must engage one bolt diameter to be OK and two bolt diameters to be safer. When a threaded fastner is torqued to proper stretch, the top three threads take 75% of the load and the remainder threads spread the remaining load between them. As time goes on the load eventually spreads out to the rest of the hole but not evenly. Of course it is just a rule of thumb and the material that you are using has a lot to do with the integrity of the threads. In cast iron I would want two diameters of stud engagement as a minimum. The nuts are a heat treated alloy and one diameter of engagement is good.
. The rule of thumb I learned from being a machinist for a thousand years is a fastner must engage one bolt diameter to be OK and two bolt diameters to be safer. When a threaded fastner is torqued to proper stretch, the top three threads take 75% of the load and the remainder threads spread the remaining load between them. As time goes on the load eventually spreads out to the rest of the hole but not evenly. Of course it is just a rule of thumb and the material that you are using has a lot to do with the integrity of the threads. In cast iron I would want two diameters of stud engagement as a minimum. The nuts are a heat treated alloy and one diameter of engagement is good.
11-23-2009, 11:56 PM
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yet he was talking about the short exaust side studs????
With the studs seated in the bottom of the hole in the block there are easily 2 full stud diameters of thread engaged. I only need to bring the stud up half of the diameter to get the nut flush with the top of the stud. I think I should still have very close to the "magic" 2 diameters of thread left engaged if I back it out that much. Then I will also have the full nut's worth of threads engaged up top. As far as calling up ARP... I don't think it would be of much worth. If several other people have run into the same problem, then I don't think that I have the wrong studs.
Thanks for the great info!
11-24-2009, 08:17 PM
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You give up too easy. If I paid hard earned cash for a product, I'd darn sure be on the phone. If ARP has become so lax with customer serive. Then its time for the general public to go some where else. And there are other place's to get head studs from.. Hailsey... Sorry I had to cough..
11-28-2009, 03:27 PM
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Well, i called up arp... kind of got what i expected. The first guy I talked to said they weren't aware of any kits getting sent out with the wrong studs. He gave me another number to call, and that guy had the same story. He said it should be ok to back them out a bit for a better fit. I did that and the truck is up and running again, but I don't think I'll be buying from arp again.
