Head Gasket Question

Discussion in 'Street/strip 400/430/455' started by Buickus Rex, Jul 19, 2003.

  1. Buickus Rex

    Buickus Rex '67 GS400 4-Speed

    Here's a question for you...do head gaskets have a shelf life?

    Here's what happened....

    About two weeks ago I decided to remove the left cylinder head to fix a leaking exhaust manifold - two bolts were broken off and it sounded like a sh*twagon. I had the usual difficult time and frustrations, but nothing that wasn't unexpected. I put it all back together but when I fired it up I had steam in the exhaust on the side I worked on and bubbles and foam in the radiator. OK, so it looks like the head gasket didn't seal. *!!#$%*!!*. A compression check showed about 180 psi on #1 and #3, about 150 on #5 and about 120 on #7. AHA!!! #7 and possibly #5 are leaking!! What's weird though is that it was pulling 20" of vacuum and idled like a rock. After taking it all apart again I could not find any visible evidence of leakage except that the #7 intake valve was nice and clean compared to the other ones (there with only about 1/2 hour of running time). But there was no smoking gun...no lump of crud between the head gasket and the head or the block...no obvious problems. (The motor was runing fine before I decided to "fix" it). Motor is basically stock '67 Buick 400" +.030".

    So I ask, do head gaskets have a shelf life? The gasket I used was a regular Fel-Pro 8494PT composition type, which was the same type that I had used previously and was still on there performing flawlessly when I decided to do this job. I bought the set about 12 yrs ago but never used them, until now...they've been in the package all this time. I've got this thing all cleaned up and ready to re-assemble, but I'm wondering if the reason for the failure was an old gasket?

    Thanks.

    Larry
     
  2. carcrazy455

    carcrazy455 Well-Known Member

    Larry, the old head gaskets should still work fine as long as they were kept flat, clean and dry. I would check the block deck and head for warpage. Sometimes some Barrs Stop Leak will help.

    Mike
     
  3. Buickus Rex

    Buickus Rex '67 GS400 4-Speed

    I didn't think the gaskets would be the problem - it was just wishful thinking.

    The thought of warpage did cross my mind, but I didn't check for it because it had been running for about 12 years without any problems. Well, I went and put a straight-edge on the head and as far as I can tell, the head is indeed warped...not end-to-end but cross-wise from intake side to exhaust side. I used the same straight edge on another Buick head and it was perfectly flat.

    Now at least I know what I have to do...

    Thanks Mike.

    Larry
     

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