ARP head bolt tq Question
05-27-2003, 12:44 PM
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ARP head bolt tq Question I was told by ARP that if I use 30 weight oil instead of their lube on the head bolts they need to be torqued at 85ft/lb instead of 70ft/lb for the 10 15mm bolts and 29ft/lb instead of 22 ft/lb for the 5 small bolts that run up top by the lifter valley cover. Is this what you guys do? Or do you guys follow the 70/22 like factory even with 30weight oil on the bolts? I just wanna make sure I get the proper tq on the bolts so I don't blow a head gasket. I was also wondering if I torque a head down but don't start the car up and then remove the head since the car was never started can I reuse the head gasket?
thanks!
Rick
thanks!
Rick
05-27-2003, 01:48 PM
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Re: ARP head bolt tq Question I've always heard that once a head gasket is squished, it can not be re-used if the head is subsequently removed.... it has nothing to do with whether the gasket gets hot...
...I could be wrong, however...
I have friend that used to drag race in the 70's. He ran straight copper gaskets on his top fuel hemi and he claimed he could adjust compression by using two or more copper gaskets...he re-used all the dodge stock head bolts.
He now uses a stock non-copper head gasket (metal/graphite) and does not re-use head bolts for his recently re-built street motor (also a Dodge but, unfortunatly, not a hemi)...
He only bought new head bolts for his set up because he says, "the factory recommends it"....
...I could be wrong, however...
I have friend that used to drag race in the 70's. He ran straight copper gaskets on his top fuel hemi and he claimed he could adjust compression by using two or more copper gaskets...he re-used all the dodge stock head bolts.
He now uses a stock non-copper head gasket (metal/graphite) and does not re-use head bolts for his recently re-built street motor (also a Dodge but, unfortunatly, not a hemi)...
He only bought new head bolts for his set up because he says, "the factory recommends it"....
05-27-2003, 08:33 PM
#6
Re: ARP head bolt tq Question You can torque like ARP recommends, or you can torque them to what to OEM specs. Either way it doesn't really matter, if you are running on the street. I personally would go with ARP's advice. It is after all their fasteners, they would know what's best. OEM bolts have varying strengths, depending on who made them.
05-27-2003, 08:36 PM
#7
Re: ARP head bolt tq Question
I've always heard that once a head gasket is squished, it can not be re-used if the head is subsequently removed.... it has nothing to do with whether the gasket gets hot...
...I could be wrong, however...
I have friend that used to drag race in the 70's. He ran straight copper gaskets on his top fuel hemi and he claimed he could adjust compression by using two or more copper gaskets...he re-used all the dodge stock head bolts.
He now uses a stock non-copper head gasket (metal/graphite) and does not re-use head bolts for his recently re-built street motor (also a Dodge but, unfortunatly, not a hemi)...
He only bought new head bolts for his set up because he says, "the factory recommends it"....
...I could be wrong, however...
I have friend that used to drag race in the 70's. He ran straight copper gaskets on his top fuel hemi and he claimed he could adjust compression by using two or more copper gaskets...he re-used all the dodge stock head bolts.
He now uses a stock non-copper head gasket (metal/graphite) and does not re-use head bolts for his recently re-built street motor (also a Dodge but, unfortunatly, not a hemi)...
He only bought new head bolts for his set up because he says, "the factory recommends it"....
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05-28-2003, 11:25 AM
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Re: ARP head bolt tq Question Torque wrench ratings on bolts is an approximation: the harder the bolt is to turn the more it stretches. It is really the stretch of the bolt that is important. ARP has measured the bolt stretch using their lubricant and concluded that 70 lb/ft of torque will generate approximately the correct amount of bolt stretch. What they are telling you now is that 30 wt motor oil will generate more thread and bolt head seat friction and will need more torque to generate the same amount of stretch of the bolt.
I'd go with what ARP is telling you. They know their bolts.
John Parsons
I'd go with what ARP is telling you. They know their bolts.
John Parsons
05-28-2003, 12:48 PM
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Re: ARP head bolt tq Question I allready have em at like 70-75...should I do one more pass at 85ft/lbs then? I am scared to break a bolt. I allready had one of the small ones break and I am scared to add more tq to the big bolts. Is it worth it going from 70-75 to the arp suggested 85? Can I just add a fourth pass at 85 or do I need to loosen the bolts and start from scratch?
05-28-2003, 12:54 PM
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Re: ARP head bolt tq Question You want to torque them in sequence and in steps. So a final step from 75 to 85 lb/ft is the way I'd do it.
Now about the small bolt: are you saying that you broke an ARP bolt using their recommended torque rating? I'd be on the phone with them instantly if that's true.
Good luck.
jp
Now about the small bolt: are you saying that you broke an ARP bolt using their recommended torque rating? I'd be on the phone with them instantly if that's true.
Good luck.
jp
05-28-2003, 01:25 PM
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Re: ARP head bolt tq Question yep I did, they sent me ten small new ones and want the small one I broke sent to them, they are gonna test it and if it proves to have been a bad bolt since it broke at 22 ft/lbs when it was supposed to be tq at 29 since I was using 30 weight oil they would pay for the cost of having the broken bolt taken out of the block and for a new head gasket....so basically just add one more pass at 85?...that would be a total of 4 passes on the 15mm bolts.thanks for your help!
Rick
Rick
05-28-2003, 01:43 PM
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Re: ARP head bolt tq Question
so basically just add one more pass at 85?
Ordinarily ARP recommends torque ratings at 75% of yield strength. So you shouldn't have any bolts that yield until past 105 lb/ft or so ...
That's why ARP is so interested in your broken bolt. They take this sort of stuff seriously, at least in my experience. How well calibrated is your torque wrench? How accurate is it at 22 lb/ft? How accurate is it at 85 lb/ft? You might want to check ...
jp
05-28-2003, 01:48 PM
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Re: ARP head bolt tq Question I am afraid that those will break...arent ARP bolts supposed to handle quite a bit more than normal before they break or strip the threads before the bolts break? I am just being paranoid I guess....breaking a head bolt wasn't a very pleasant experience 
anyways thanks JP, your advice has been VERY helpful!!!!
anyways thanks JP, your advice has been VERY helpful!!!!
05-28-2003, 01:52 PM
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Re: ARP head bolt tq Question brand new wrench...and all the other bolts on both the heads tq down fine no prob after checking them like 4 times or so...this was the last damn bolt too...#15 on the sequence...god Hates me 
