77 350 engine gasket issue

Discussion in 'Small Block Tech' started by JStov, Sep 21, 2019.

  1. JStov

    JStov Well-Known Member

    I’m in a crazy mess and I need help, last month I had a mishap with my bone stock 77 Buick 350 with 60,000 miles some how a little screw fell into the intake and landing in cylinder #1, we couldn’t fish out using the magnet method so we ended up having to tear into it removing the intake manifold and head and exhaust manifold. Well I hadn’t Any leaks or signs of head problems but we did have the head checked and it was good, so we bolted everything back together using stock bolts and fel-pro 8462pt1 gasket. Well the problem it leaked like crazy bottom center between 3-5 so we ended up redoing it again thinking maybe we but it on the wrong side up, but it wasn’t so I went back to grab another of the same gasket and redid it over again, being this time I asked him what are you torquing the bolts too, he said 90lbs and I them went and got my manual and it stated for 77 100lbs and then 130lbs. We did that today and it’s still leaking. I’m so confused and pissed and the same time cause 1st this wouldn’t have happened if the screw thingy never happed btw it doesn’t look like it did any damage so far. But my for anyone what are we missing could it be that this is a bad replacement head gasket, or maybe I need new bolts I took them up to some of the summit old heads here in Arlington TX and they said they look very good and reusable. So I just don’t know please any advise would be appreciated thanks in advance
     
  2. flynbuick

    flynbuick Guest

    We moved your thread to small block tech.
     
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  3. JStov

    JStov Well-Known Member

    Thank you
     
  4. Dr. Roger

    Dr. Roger Stock enthusiast

    Is it leaking coolant?

    Years ago I rebuilt one and put the head gaskets in upside down (wasn't paying attention that day). Went to fill up the radiator and it all ran out on the floor. Had to break it all down again (including new intake gasket), and now I pay close attention to the the head gasket warning "this side up."

    Could be a bad head gasket. Somewhere in the Buick service manual it says to put "perfect seal" on the head bolts prior to installing or you will damage the threads. Also have to make sure they are clean (hit em with a wire wheel). Assume you are following the correct torque sequence.
     
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  5. Dr. Roger

    Dr. Roger Stock enthusiast

    I also run a tap into the block to clean up the old threads before I install the head.
     
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  6. JStov

    JStov Well-Known Member

    Yes that’s what I thought as well as far as the direction and placement but it was on right we even hit it with the tacky copper spray and gonna go at it again tomorrow, as far as the bolts go yes we clean and oil them up pretty well so still scratching my head I’m just wondering if there us a thicker one on the market for stock motors that’s preferred over the felpro 8264pt1
     
  7. JStov

    JStov Well-Known Member

    Ok will try that and hope the 3rd time is a charm would you go with the same brand of gasket or do you recommend one over the one I used felpro 8264pt1
     
  8. Dr. Roger

    Dr. Roger Stock enthusiast

    Yeah, you don't want to oil the head bolts. Clean them up with some solvent and put thread seal on them. With oil, a bolt gets way tighter than what it is supposed to be at the same torque reading. Can't recall number of the gasket I use, Fel Pro from Autozone is all I remember. Don't recall the final torque on a 77 350, but on a 71-72, final head bolt torque is 75 on a 350 and 100 on a 455. You could be putting too much torque on them. Hopefully, someone else here knows if a 77 350 differs in torque specs. I also like to let them sit for a day for the sealer to set up before i put in water and fire up.
     
  9. JStov

    JStov Well-Known Member

    These were from the manual
     

    Attached Files:

  10. Dr. Roger

    Dr. Roger Stock enthusiast

    Ok, your torque should be good. Guess the later models lubed the threads with oil, so you're good there also. If it didn't leak before, it's probably not anything warped. Try taping out the block and maybe some new bolts. Might also try a different brand of head gasket. I know how much it stinks taking these apart and putting them back together multiple times, especially with those ridiculously heavy intakes. Enough to drive you crazy.
     
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  11. sean Buick 76

    sean Buick 76 Buick Nut

    Yes I never use thread sealer on Buick 350 heads. I’ve never had an issue with those Felpro gaskets either. The stock bolts are fine.

    It sucks but I would just try again. I do re torque the bolts after one heat cycle.

    I would avoid any sealants or sprays. Those gaskets are meant to be used dry.

    Is your torque wrench verified? Try another one or have it calibrated.
     
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  12. JStov

    JStov Well-Known Member

    Yes indeed plus I’ve got the old heavy beastly intake manifold dreading this
     
  13. JStov

    JStov Well-Known Member

    Yes I’m gonna purchase one tomorrow, I used his and his a Chevy guy so he was not following the pattern, is it to late to go back and start over on the torquing sequence
     
  14. sean Buick 76

    sean Buick 76 Buick Nut

    No if you haven’t fired it up it’s not to late to follow the pattern. If it’s already been started up and leaked then buy a new gasket or at least remove and fully inspect the gasket. You MUST follow the right sequence, otherwise it will leak.

    If it’s been installed and torqued in the wrong pattern then just loosen all the bolts and re do it properly.
     
  15. JStov

    JStov Well-Known Member

    Ok thanks Sean, I will do that but you that 130lb torque really scares me Just being honest
     
  16. alec296

    alec296 i need another buick

    100 and 130 is too tight. . 75 max.
    Still sounds like you have gasket on wrong. . Check your freeze plugs .
    I have reused fel pro gaskets. I don’t see what you have happening. You should probably post pictures of block, block with gasket on.
     
  17. JStov

    JStov Well-Known Member

    Ok will do when I get it off
     
  18. alec296

    alec296 i need another buick

    Spray head bolt threads with wd 40. They torque better with alittle lube.
     
  19. 1973gs

    1973gs Well-Known Member

    Do you have an Olds 350 or a Buick 350? I believe that you're in the wrong section of the manual. What is the 5th digit of the vin? X,L,K,H, or R? Your picture looks like an Olds engine. X is Buick. If you have a Buick and torqued them using Olds specs, replace the bolts and check the head for warpage. Buick head bolts only torqued to 80.
     
    Last edited: Sep 22, 2019
  20. alec296

    alec296 i need another buick

    is the distributer in the front or rear?
     

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