V8 SHO Catastrophic Shim Failure

Discussion in 'V8 - Emergency Issues' started by Qshiplvr, Jan 6, 2019.

  1. Qshiplvr

    Qshiplvr Member

    Joined:
    May 28, 2016
    Messages:
    78
    Likes Received:
    22
    Occupation:
    Fin Svcs
    Location:
    P Springs
    Well, it happened. It started with a soft ticking, which turned into a definite clicking. I knew something was up, so decided to turn into a shopping mall driveway to check it out. By the time I found a parking space, the clicking was now a clacking. I shut it off, opened the hood, and asked my husband to fire up the engine while I listened. The engine now clanking and sounding like it was missing a cylinder, so I said shut it off, and called AAA to tow it home (I was on the way to pick up some meds at pharmacy, so not too far away).

    I called my buddy John The SHO guy, and had him talk me through what to do next. It took a few weeks for me to gather up the courage to open up the valve cover, and this is the carnage I saw.

    It appears that the shim sitting in the bucket disintegrated. It may have been an occlusion or fracture that eventually led to the shim bifurcating in half and the cam rubbing the pieces against the camshaft tower support that broke one half into shrapnel, and possibly caused shavings to become deposited on the inside of the valve cover.

    In a couple of weeks I'll have the SHO towed to John The SHO guy's place and he'll try to assess the damage, replace the shims and hopefully get her back on the road. While we are in there, I think I'll replace the plastic "Y" connector that distributes the coolant between both heads in the valley of the V.

    Wish us luck.
     

    Attached Files:

  2. bpd1151

    bpd1151 Lurking Around

    Joined:
    Feb 21, 2010
    Messages:
    1,790
    Likes Received:
    3,237
    Gender:
    Male
    Occupation:
    LEO 23+yrs
    Location:
    SHOcago 'Burbs
    Good luck and much success with all the repairs looming.

    Video is must when it's back up and running like the champ that it is!

    Sent from my SM-N950U using Tapatalk
     
  3. luigisho

    luigisho SHO Member

    Joined:
    Nov 2, 2001
    Messages:
    8,429
    Likes Received:
    1,504
    Location:
    va beach,va
    Home Page:
    If there is considerable damage I saw paul Nimz on the v8sho email list was parting/selling a v8. If you need a replacement head that might be the way to go. His user name on this forum is SHOZ123 if you want to drop him a line or you can join the v8 mailing list
    https://groups.google.com/forum/#!topic/v8sho/i3rYypEDCCY

    not sure of mileage or condition
     
    SHOZ123, Qshiplvr and bpd1151 like this.
  4. shoftw

    shoftw SHO Member

    Joined:
    May 30, 2009
    Messages:
    178
    Likes Received:
    24
    Gender:
    Male
    Location:
    Illinois
    Wow this makes me really want to do the 100k inspection on my shims now.
     
    gamefanatic likes this.
  5. E1

    E1 Crash Tested

    Joined:
    Jan 24, 2003
    Messages:
    464
    Likes Received:
    166
    Occupation:
    Printing mechanic/engineer
    Location:
    Chicago area
    Home Page:
    Wild!

    I have seen a couple shims shoot out over the years, but never one break up.

    Have you been able to find all of the pieces of it? This would be my biggest worry if this were my engine. That shim is freakin rock hard and even a small bit of it will chew the bajeezus out of anything it gets up against.
    You should be able to clean up that head sufficiently to accept a new bucket and shim.

    I too have a 'few' parts laying around if you have trouble finding something.
     
    GEN 3 SHO FAN and bpd1151 like this.
  6. Qshiplvr

    Qshiplvr Member

    Joined:
    May 28, 2016
    Messages:
    78
    Likes Received:
    22
    Occupation:
    Fin Svcs
    Location:
    P Springs
    Everyone: Thank you all for the replies. I am REALLY hoping that the head is useable as is, and all I need to do is find another bucket and a shim that fits, plus redo all the rest of the shims, whilst cleaning out the oil and screen for the shrapnel that happened when the shim failed.

    Will let you know in a few weeks. John thinks he has all the spare parts we need to get this on the road again. Won't know until we dig deeper into the engine.
     
  7. luigisho

    luigisho SHO Member

    Joined:
    Nov 2, 2001
    Messages:
    8,429
    Likes Received:
    1,504
    Location:
    va beach,va
    Home Page:
    No damage to the camshaft lobe on that shim?
     
  8. 99sho-time

    99sho-time SHO Member

    Joined:
    Dec 15, 2015
    Messages:
    249
    Likes Received:
    36
    Gender:
    Male
    wow ugly and scary I wonder why. Measure the rest of the clearences? My impression based on the observation of other great sho members and my own is that these engines dont wear shims out. which is why this odd to me. that engine doesn't look dirty either.
     
  9. SHOVNST

    SHOVNST Blood type: SHO+

    Joined:
    Jan 24, 2004
    Messages:
    736
    Likes Received:
    341
    Location:
    Niwot, CO
     
  10. GEN 3 SHO FAN

    GEN 3 SHO FAN SHO Member

    Joined:
    Jan 31, 2015
    Messages:
    613
    Likes Received:
    165
    Occupation:
    Records manager
    Location:
    Canada
    I never rode a thing like this before too. Can it be caused by the beginning of the desynchronization of the cam ? The piston starts to touch the valve enough to create more friction on the shim... (Just asking.)

    We have some cam welding failures reported over time.
     
  11. luigisho

    luigisho SHO Member

    Joined:
    Nov 2, 2001
    Messages:
    8,429
    Likes Received:
    1,504
    Location:
    va beach,va
    Home Page:
    I was thinking that to myself as well. More cam weld failures relative to active members last few years.
     
  12. GEN 3 SHO FAN

    GEN 3 SHO FAN SHO Member

    Joined:
    Jan 31, 2015
    Messages:
    613
    Likes Received:
    165
    Occupation:
    Records manager
    Location:
    Canada
    Welding seems good on the photos however.

    Can the main sprocket could be desynchronised ? IIRC, the main sprocket is also pressed onto the camshaft and cams/lobes seem also pressed onto the camshaft... If too much resistance was applied on the cam, this one may have possibly moved, no? (Watch if you see small grinding traces under the lobe on the camshaft.)

    index.jpg

    If it's the case, the best way to secure the motor could be to change this camshaft sadly. According to another picture, isn't the case. Seems in the same possition as his sister.

    Good luck,
     
  13. Stan Phillips

    Stan Phillips New Member

    Joined:
    Jan 7, 2019
    Messages:
    2
    Likes Received:
    0
    Gender:
    Male
    Location:
    Jefferson Twp, Pa
     
  14. stephen newberg

    stephen newberg Moderator Staff Member

    Joined:
    Jan 15, 2001
    Messages:
    3,205
    Likes Received:
    290
    Occupation:
    No Idea
    Location:
    Ladysmith, BC, Canada
    Yes, best of luck with it, Stan.

    pax, smn
     
  15. Stan Phillips

    Stan Phillips New Member

    Joined:
    Jan 7, 2019
    Messages:
    2
    Likes Received:
    0
    Gender:
    Male
    Location:
    Jefferson Twp, Pa
    Sorry...could not type a response to the last comment.
    I had the shim failure also.
    I got the shim out, but it looks like the top edges of the "bucket" took a pounding.
    Is it possible to pull the bucket out without pulling the cam off ??
    If so, any advise on how to pull the bucket out ?

    I have a spare head that I can salvage parts.
     
  16. gamefanatic

    gamefanatic SHO Member

    Joined:
    Feb 20, 2005
    Messages:
    301
    Likes Received:
    90
    Location:
    Barstow, CA
    Not possible to get the bucket. It needs to come up almost 2".
     

Share This Page

If you wish to help keep SHOforum running, please click the donation button below