how many times can you reuse stock head bolts?

Discussion in 'Fox 5.0 Mustang' started by 90blue5.0, Jan 15, 2004.

  1. 90blue5.0 Founding Member

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    I have a '90 GT and this is the second time that the heads have been off, can I still use the same bolts?
  2. lxsteed Founding Member

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    I'm not 100% sure, but I think the head bolts are "Torque to yeild." which means if you torque them down once, thats all you can use them. I'd buy a new set anyway. Cheap insurance.
  3. Gearbanger 101 SuperMod

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    I'm on my third time with mine (that I know of) and they're fine. I'd say if you were building an engine with a lot of compression, boost, nitrous, or high dollar aluminium heads, I'd upgrade to head studs, but for a basic rebuild with Iron heads, the stock bolts can be used again. Some people will replace them, regardless, but they're not torque to yield, so I don't see any real problem.
  4. 5LugFoxFanatic LOVE AND PEACE!

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    Spend the 30-40 on ARP head bolts. Don't be a cheapass.
  5. cleanLX Founding Member

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    You sure about that?
    I went with ARP studs, necessary for a stocker no, but I definatly can use them over and over(and have), and you do get a more accurate tq on them... well, from what I've been told...
  6. 90blue5.0 Founding Member

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    If they are re-usable then I will re-ruse them. There is no point buying new ones if the old ones will work just as good.
  7. Gearbanger 101 SuperMod

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    Stock head bolts are definitely not torque to yield. Just make sure to run a tap down the bolt-holes in the block, make sure the threads are clean before installing them. Also don’t forget to oil the threads and just under the head of the bolts as well as use some thread sealer on the lower bolts, as they run into the water jackets on the block.

    I’ve reused stock bolts dozens of times as have many people. Like I said before, unless there are any drastic parameters like forced induction, high compression, nitrous, or aluminium heads, I wouldn’t worry too much about the stock bolts. You’ll be able to torque them accurately enough for iron heads. :nice:
  8. 90blue5.0 Founding Member

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    should I oil the head gaskets before installing them?
  9. Gearbanger 101 SuperMod

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    No, the gaskets and block should be clean and dry before you lay them on. And remember, they only go on one way. But I like to use a thick bead of RVT Black silicone in place of the end gaskets on the lower intake manifold when I put it back on. You use the end gaskets that come with it, but I find that the silicone seals better. If you’re going to use the gaskets, just make sure to give them an ample dab in each corner.....as well as a thin layer around the intake and water jacket ports of the heads before I lay on the manifold gaskets.
  10. Maryland Stang Active Member

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    V-6 head bolts can not be reused. V-8 bolts can be reused. Just do what Gearbanger 101 told you.
  11. gaslight Founding Member

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    whoever tells you that you can reuse those TORQUE TO YIELD bolts is a meathead. You can't reuse them. They stretch after the first use. Get a manual for your car. In the manual it will tell you not to reuse those bolts and it will tell you the correct way to do things. Take my advice and get the book.
  12. RydeOn Licensed to Chill

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    we should do a poll on this since there are so many conflicting answers :D

    can you reuse the ARPs?
  13. Michael Yount New Member

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    ARP does not make torque to yield fasteners - ARP are NOT torque to yield. Provided they're not overtorqued, they can be reused.

    My understanding is that the factory switched to torque to yield head bolts at some point - I have a vague recollection that the SN95 cars (94/95) have torque to yield head bolts, but don't hold me to it. Torque to yield bolts can only be "torqued to yield" one time - can't be reused.
  14. 90blue5.0 Founding Member

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    There were two different style of bolts the flanged style and non-flanged, the flanged are to yield the other is not.
  15. retro50 New Member

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    90 blue5.0 has the correct answer. Ford used torque to yield head bolts on 93 and up 5.0L engines and they have flanges under the heads of the bolts. You can replace them with the earlier head bolt design and use the early torque spec.
  16. 85GTKid Founding Member

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    I reused my 85s headbolts once with no trouble but only had the heads on for 5 months before swapping heads and using new bolts.
  17. ashford Member

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    i think in the 90's somewhere they went to torque to yield. well anyway the non torqu to yield can be use a few time but not indefinetly. i had a machinist put hardened valve seats in my 289. he screwed up the seat alignment i think because 5 seperate times i got a stuck exhaust valve after the engine got warmed up and had to pull the heads off 5 different times. about the 4th time when installing one of the head bolts didn't feel quite right and snapped off at about 60 foot pounds. not a big deal the bolt came right out with a screw driver, but ruined a gasket. ive ran across 2 other head bolts on other engine that didn't feel right so pulled them out stuck em in a vise and bent them and threw em away.
    an easy way to tell if the head bolts are torqu to yield is to go your local parts store and if they have them in stock more than likely their torque to yeild.
  18. Maryland Stang Active Member

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    gaslight wrote:

    whoever tells you that you can reuse those TORQUE TO YIELD bolts is a meathead.

    I used my Haynes manual as a reference before I posted. When it said to make sure the head bolts went back into the same locations that they came out of I was sure they were reusable.

    Ref: Haynes Ford Mustang & Mecury Capri - Section 2D-12 #9
  19. Gearbanger 101 SuperMod

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    Nobody said anything about reuseing torque to yield bolts.....meathead. ;)
  20. YardSpecial New Member

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    1990 and up are TTY bolts and have a washer under the bolt head.

    Should not be used more then 3 times.

    prior 90 bolts should only be used once.

    Page 214 in the Ford Mustang 5.0 book

    So that the info I go by.

    Intake torque is also important, to tight and U could blow the head gasket ! (common)

    The Meathead !

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