headbolts keep breaking in a cumminms 400 big cam

Discussion in 'Peterbilt Forum' started by black smoke, Dec 30, 2011.

  1. black smoke

    black smoke Bobtail Member

    3
    0
    Dec 30, 2011
    Cedar Grove, IN
    0
    The headbolts in the rear head keep breaking in my cummins 400 big cam. What causes this? Does anyone know why or have the same problem?
     
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  3. 1988pete379

    1988pete379 Light Load Member

    193
    75
    Feb 28, 2009
    North East TX
    0
    What yr model is the engine got to be old
     
  4. black smoke

    black smoke Bobtail Member

    3
    0
    Dec 30, 2011
    Cedar Grove, IN
    0
  5. black smoke

    black smoke Bobtail Member

    3
    0
    Dec 30, 2011
    Cedar Grove, IN
    0
  6. bender

    bender Road Train Member

    2,105
    1,347
    Jul 20, 2010
    Don't Kid Yourself
    0
    The head bolts get corroded and pitted from moisture intrusion. This weakens them and they pop from the high torque value put on them when installed.
     
  7. companyman

    companyman Heavy Load Member

    747
    122
    Nov 17, 2011
    0
    Get used to it. I used to breakbone every few months. Expensive buggers too.

    One thing that may help. The big cam is not a modern engine. It likes to run higher rpm. They humm right along at 2300rpm. If you run it low rpm like a modern engine it breaks even more head bolts.

    They are fun engines for a toy, miserable engines for working every day
     
  8. CondoCruiser

    CondoCruiser The Legend

    19,726
    18,731
    Apr 18, 2010
    Tennessee
    0
    How are you torquing?
     
  9. Prairie Boy

    Prairie Boy Road Train Member

    3,258
    1,911
    Nov 18, 2010
    Edmonton, AB
    0
    Big Cam 400's were not meant to be jaking at high RPM's.
     
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.