Beating Out Main Bearing

Discussion in 'PSI Superchargers Tech Questions' started by Mike Canter, Sep 5, 2006.

  1. Mike Canter

    Mike Canter Top Dragster
    Staff Member

    Joined:
    Mar 10, 2004
    Messages:
    4,630
    Likes Received:
    189
    On a blower motor is it a common thing to beat up number 2 lower main bearing after several races? I use a front bearing support but it still happens. It is not what I consider bad but it is the only main bearing I really ever have to check and change.

    It there anything that can be done to stop it?

    Thanks
     
    #1
    Mike Canter, Sep 5, 2006
  2. Randy G.

    Randy G. Top Alcohol

    Joined:
    Jun 9, 2003
    Messages:
    1,902
    Likes Received:
    38
    Number 2 main bearing cap half even with a crank support is the first to show some "wear" followed closely by number 4 if you're leaning on it. Ours shows sympathy pains whenever we get after it or whenever the rev limiter gets smacked.

    We drop ours ever few runs depending on what happened on those runs. To say "after several races" sounds pretty good to me.
     
    #2
    Randy G., Sep 5, 2006
  3. Mike Canter

    Mike Canter Top Dragster
    Staff Member

    Joined:
    Mar 10, 2004
    Messages:
    4,630
    Likes Received:
    189
    We are only running in the 1/8 mile and shift at 8600 rpm (Ford Hemi Motor). My number four is the thrust bearing it it never shows wear. Well it makes me feel better to know that is not unusual.....thanks.
     
    #3
    Mike Canter, Sep 5, 2006
  4. T.Howell

    T.Howell Member

    Joined:
    May 21, 2003
    Messages:
    172
    Likes Received:
    0
    Mike, other than the rear main, #2 usually shows some distress before the others as Randy has mentioned. In older blocks or if left in for a length of time #2 lower will start showing some twist. I have seen this on three different teams. My guess is this bearing is moving and twisting every run and shows up as excessive wear and getting into the radius. A double tanged bottom half often cures this.

    edit: these were all blown hemis. TFX and BAE.
     
    #4
    T.Howell, Sep 5, 2006
  5. Randy G.

    Randy G. Top Alcohol

    Joined:
    Jun 9, 2003
    Messages:
    1,902
    Likes Received:
    38
    Problem got slightly better when we switched from cast to forged blocks several years ago.
     
    #5
    Randy G., Sep 5, 2006
  6. Mike Canter

    Mike Canter Top Dragster
    Staff Member

    Joined:
    Mar 10, 2004
    Messages:
    4,630
    Likes Received:
    189
    So does that indicate that it is a block twisting or moving or flexing problem? Is the crankshaft and front bearing support the same?
     
    #6
    Mike Canter, Sep 5, 2006
  7. Dave Germain

    Dave Germain New Member

    Joined:
    Aug 1, 2003
    Messages:
    896
    Likes Received:
    0
    I wonder if you are getting wear to #2 main due to crank flex from the blower belt. The front of the crank pivots on #1 and it lands on #2. The crank supports are supposed to stop that but many aren't really beefy enough. Dave Germain
     
    #7
    Dave Germain, Sep 6, 2006
  8. ITS IN MY BLOOD

    ITS IN MY BLOOD TAFC

    Joined:
    Dec 2, 2004
    Messages:
    1,093
    Likes Received:
    2
    try checking this..
    with mtr on stand and main caps off, put a dial indacator
    on the mains of the crank and rotate it around, i have began assembly on
    some blown mtrs before and have found the crank itself to be
    out of round ,..just a thought,.. you might check it.
     
    #8
    ITS IN MY BLOOD, Sep 6, 2006
  9. Mike Canter

    Mike Canter Top Dragster
    Staff Member

    Joined:
    Mar 10, 2004
    Messages:
    4,630
    Likes Received:
    189
    Checked that it is perfectly round and no bend. Thanks
     
    #9
    Mike Canter, Sep 7, 2006
  10. Randy G.

    Randy G. Top Alcohol

    Joined:
    Jun 9, 2003
    Messages:
    1,902
    Likes Received:
    38
    The only known cure is to switch to golfing.
     
    #10
    Randy G., Sep 7, 2006
  11. Mike Canter

    Mike Canter Top Dragster
    Staff Member

    Joined:
    Mar 10, 2004
    Messages:
    4,630
    Likes Received:
    189
    That costs more money and is boring.....Thanks Randy

    Also it doesn't look right at a posh country club to have grease under your nails.
     
    #11
    Mike Canter, Sep 7, 2006
  12. Dave Germain

    Dave Germain New Member

    Joined:
    Aug 1, 2003
    Messages:
    896
    Likes Received:
    0
    Golf- a perfectly good walk spoiled by a little white ball.
     
    #12
    Dave Germain, Sep 10, 2006

Share This Page





XenPorta 2 PRO © Jason Axelrod from 8WAYRUN.COM