Rounded of hex bolt in engine cylinder head
Results 1 to 4 of 4
  1. #1
    R/C Apprentice
    Join Date
    Feb 2009
    Location
    Adelaide SA
    Posts
    163
    Rep Power
    11

    Rounded of hex bolt in engine cylinder head

    Hi

    i have a .30 Nosram and one of the 4 hex bolts in the cylinder head has rounded itself off. I can get the other 3 out, but the 4th one has rounded off and just doesnt move

    Any ideas or options? other than a new engine

  2. Remove Advertisements
    AUSRC.COM
    Advertisements
     

  3. #2
    R/C Guru eXraycer's Avatar
    Join Date
    May 2009
    Posts
    848
    Rep Power
    11
    A torx bit can usually get some purchase where a hex won't. Pick a size which is nice and tight and use some heat on the area too. If that fails then you have to drill the bolt head and use a very small ezy-out.
    Rok RC - large scale tuning parts.

  4. #3
    R/C Newbie
    Join Date
    May 2010
    Posts
    8
    Rep Power
    0
    Quote Originally Posted by Bruce Campbell View Post
    Hi

    i have a .30 Nosram and one of the 4 hex bolts in the cylinder head has rounded itself off. I can get the other 3 out, but the 4th one has rounded off and just doesnt move

    Any ideas or options? other than a new engine
    I just bought a bulk lot of engines and needed to drill out about 20 of the bolts, quite easy, if it's a 3mm bolt just hold it flat and square in a vertical drill and use a nice sharp 1/8th (3.2mm) drill bit and carefully drill the head off, it will break loose and stay on the drill bit, then lift the head off and undo the 'stud'.
    BB

  5. Remove Advertisements
    AUSRC.COM
    Advertisements
     

  6. #4
    R/C Apprentice
    Join Date
    Aug 2010
    Posts
    111
    Rep Power
    10
    I had this happen on one of my OS engines, I just grabbed a cobalt drill bit and could use a cordless drill to take off the tops of the screws. These screws were sunken also.

    I could then take the cooling heard off and unscrew the stub with some pliers.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •