Need to retorque the head with used ARP's?

IwantMKIII

WVU MAEngineering
Jun 12, 2007
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Perkasie, PA
Just what the title says. I know new ARP head studs will elongate the first time around, but given these are used, would a re-torque be advised or just unnecessary?

'Rebuld' Update: Car just started for the first time tonight. Full flow oil system took awhile to get all the kinks (fitment issues and a leaky line) worked out; scary how much oil is leaked through the system so quickly. Ran into some electrical issues as well, so far turned out to be battery terminals not quite as tight as I thought they were. Experiencing ultra low idle as well, not solved, possible ISC related. No codes even after first start.
 

Beefy_Heafy

Toyota Love
Nov 9, 2009
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South East Qld
As far as i know they don't need to be re-torqued at all. Mine have been used twice also due to engine failure for unrelated reasons on first build. And I have been boosting the engine pretty hard with no issues. I thought re-torquing head bolts/studs was more dependent on the gasket used not the fasteners?
 

ForcedTorque

Join the 92 Owners Group
Jul 11, 2005
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I don't think it could hurt anything to break open a cam cover and check the torque on a couple of them. If they aren't where you want them, torque them properly. I suspect they'll be fine, but would be interested to see if they weren't.
 

empera

Authorized Vendor
Mar 30, 2005
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didnt have to do it in my old engine, havent done it in my new one......both are good.
 

adampecush

Regular Supramaniac
May 11, 2006
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Edmonton
Unless the studs are torque to yield, they will not elongate unless you have tightened them excessively. Re-torque is essentially required for loss of stud/bolt preload due to the settling and compression of the gasket/fastener contact surfaces. Re-torque as you would when installing new studs.
 

JimR

Supramania Contributor
Mar 30, 2005
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ARP hardware should never be permanently elongated after use. If a bolt or stud is more than 0.001" longer than original, it may have been overloaded and weakened. However, you can't tell this unless you measure the hardware with a micrometer before installation.

My personal recommendation is that if you see a 0.01" difference in-between bolt sizes while comparing them to eachother, this would be cause for concern. I have recorded up to a 0.005" difference in lengths on my new rod bolts before installation.

Source: http://arp-bolts.com/Tech/TechInstall.html
 

shaeff

Kurt is FTMFW x2!!!!
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Mar 30, 2005
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I would retorque. It takes less than a half hour with a stock manifold. Even less if you have a FFIM.
 

IJ.

Grumpy Old Man
Mar 30, 2005
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The "official" word I got from Cometic way back was any time NEW hardware is used it needs to be retorqued, my take on this after many 7M builds/rebuilds is that it needs to be done EVERYTIME no matter what as a few studs in the middle of the head are always looser than the ends.
 

JimR

Supramania Contributor
Mar 30, 2005
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I also agree a re-torque is a good idea, for the reasons adampecush has listed.