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| maccamillion |
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Age: 32 Posts: 69 Joined: 11th May 2012 Ride: 94 tickford enhanced xg ute Location: devonport |
here is the deal. approximately 15mths ago i replaced the head gasket in my xg tickford ute. when i did it, i accidentally did the first bolt up 90° more than the written torque spec
 . i then decided to continue with the rest all with the extra 90°. to my suprise, it has actually lasted till just 2 days ago. i honestly expected it to blow ages ago considering i do alot of heavy towing and i absolutely love the limiter bash......i really love the limiter!!!!!  .Has anyone else tried to over torque their head bolts? and if so, by how much and how long did it last? i am considering trying for 180° over but only if someone else has done it successfully. otherwise its 90° again 
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| Shortshift |
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Ummm....you do realise that these bolts are designed to stretch and that the torque specs are determined by the manufacturers after testing them? Overtightening the head bolts can lead to them snapping off or stripping thread.
_________________ AU2 XR8 with Raptor VL, ported Yella Terra GT40P heads, Scorpion 1.6 RRs, XE264HR-14 Comp Cam, ceramic coated Hurricane Headers, 60lb injectors, Walbro 255, 200cfi cats, 3" exhaust & Snow Performance water methanol injection |
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| Jonathan Kakousidis |
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there is 2 ways of doing the head bolts.
depending on which gasket specs your using. EA-EL Graphite Gasket Finger tighten the bolts, then torque them to 40nm, t hen turn 90 degrees. AU MLS Finger tighten, torque to 30nm, then turn 90 degrees, then undo them, tighten to 30nm , then turn 120 degrees.
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| maccamillion |
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Age: 32 Posts: 69 Joined: 11th May 2012 Ride: 94 tickford enhanced xg ute Location: devonport |
yes i have done both types of gasket. this is for graphite atm. MLS will be going on my new engine when its built. i had no issue with undoing, stripping or snapping head bolts. has anyone actually done this before? even as an experiment?
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| Jonathan Kakousidis |
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i don't think anyone has played games with head bolts for a good reason.
i is a pain in the a*** to redo, (new gasket, bolts, time and should have the head at least check for squareness or machined) specially when the recommended specs work quite well. but in saying that if you do try it, keep some detailed info on what you did and how it went.
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| TROYMAN |
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over tightening the head bolts cause them to stretch and loose the torque prematurely , that's probably why its failing now, a properly done head gasket should last in excess of 5 years. much much longer if you use the mls gasket..
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| cjh |
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TROYMAN wrote: over tightening the head bolts cause them to stretch and loose the torque prematurely , that's probably why its failing now, a properly done head gasket should last in excess of 5 years. much much longer if you use the mls gasket.. I replaced the head gasket on my ED back in 2008, using a std type composite head gasket. I change the coolant every 2 years, Repco brand, and haven't had a problem. I have 180-185 psi compression, dry test. The problems I have seen with head gasket failure, is people don't change their coolant.....just like they don't change their brake fluid. My 2 cents.
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| cjh |
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Have a look at the coolant tank....2008 and 2013 the pics were taken.........
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