Cam bearing movement.

Discussion in 'Race 400/430/455' started by Billy, Jun 6, 2022.

  1. Billy

    Billy Well-Known Member

    Ever see this happen.
    TA dual groove cam bearings.
    Tried to send it to Jim in a conversation.
    Motor still had good oil pressure.
    Pulled it down to replace a leaking rear main seal and found this.
    Rod & main bearings look good.
     

    Attached Files:

    Last edited: Jun 6, 2022
  2. hwprouty

    hwprouty Platinum Level Contributor

    Wow!
    Those moved quite a bit...
    Following.
     
  3. Billy

    Billy Well-Known Member

    It's the second cam bearing back from the front of the block.
    All other bearings are good.
    All the cam bearings and journals on the camshaft look good & clean with minimal wear.
     
  4. sean Buick 76

    sean Buick 76 Buick Nut

    Tear it down to a bare block and start over. I’m not sure how to fix a block if the bearing bores are worn over sized
     
  5. philbquick

    philbquick Founders Club Member

    Loctite 648. Don't get it in the oil groove.
     
    sean Buick 76 likes this.
  6. Thumper (aka greatscat)

    Thumper (aka greatscat) Well-Known Member

    If they are oversize and no crush,get V6 cam bearings and align hone.
     
    nickbuickgs and Marv Marksberry like this.
  7. dan zepnick

    dan zepnick Well-Known Member

    Yikes,at least it doesn't look burnt or scored. Yet anyway. I have one better...ta grooved cam bearings that were in a shortblock I bought. No oil to the drivers side. Will be pulling it down this week. Dam the bad luck!
     
  8. Marv Marksberry

    Marv Marksberry Well-Known Member

    The only oversized Buick Cam Bearings that I have ever seen is .020 oversized for the Buick V6, as Thumper suggests.
    I have a set put back for one of my 445’s that needs to be line bored. I can post the part number tomorrow.
     
    Dano likes this.
  9. Billy

    Billy Well-Known Member

    The camshaft is a GS-105, all journal's look good.
    I will measure all my cam bores and compare them.
    Also all the cam bearings still look good.
    I will reinstall the old cam bearing just to see how tight it is.
     
  10. Stevem

    Stevem Well-Known Member

    Boy, you need a thrust Bearing on that Cam, lol!
     
  11. hugger

    hugger Well-Known Member

    Undoubtedly a bearing spun in that bore at somepoint,...got a mess there tho
     
  12. Thumper (aka greatscat)

    Thumper (aka greatscat) Well-Known Member

    Removing and reinstalling cam bearings you will lose some crush so may be more likely to walk or spin. If all the other bearings but the one is stable try replacing the one that moved and hopefully it installs with interference,
     
  13. Billy

    Billy Well-Known Member

    Well here's the thing, the bearing never spun, oil holes were still at the 3 & 7 o'clock position before I removed it.
    Cam bore is clean with no signs of wear or scuffing.
    I do have a new set of TA bearings to install, I will not reuse the old bearings.
    I will measure the cam tunnel bores and compare them, then go from there.
     
  14. Billy

    Billy Well-Known Member

    Also luckily the cam bearing never touched the lifter.
    Motor still had good oil pressure.
    I pulled the motor to repair a leaking rear main seal and this is what I found.
    Pulled the crank and all bearings look good with some slight wear, but clean, including the crank journals.
     
  15. Billy

    Billy Well-Known Member

    I did not build this motor.
    But wonder if that one cam bearing was tapped in a little to far upon assembly.
     
  16. hugger

    hugger Well-Known Member

    Would have been hard not to notice that tho
     
  17. Jim Weise

    Jim Weise EFI/DIS 482

    Billy, As I said in my PM, you must carefully inspect that main bulkhead for cracks. I have seen this only once in my years, that was my own race motor, that started to flash the low oil pressure pro light at us one day.. popped the intake off, and it was out just a little farther than yours. That one was number 3, and there was a hairline crack from the main, all the way to the cam tunnel.

    If you find no crack, then your going to have to measure that hole to see what size it is. Something is funky there.. I don't suspect any kind of installation error.

    My money is on the block is broken..

    JW
     
    patwhac, TrunkMonkey and Dano like this.
  18. Billy

    Billy Well-Known Member

    OK will do.
     
  19. Billy

    Billy Well-Known Member

    Jim hits the nail on the head.
     

    Attached Files:

    patwhac likes this.
  20. Billy

    Billy Well-Known Member

    Has a crack on both sides from the main oil feed hole down to the tunnel.
    I have extra blocks waiting.
     
    TrunkMonkey likes this.

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