Is Line Boring An Engine Block Necessary Or Should You Just Replace The Bearings

Posted in Internal Engine Parts

I recently got a engine block that looks great, 60k on it but I bought a new crankshaft, and upgraded engine parts. MY friend is telling me I don’t have to get the block line bored, but to just replace the bearings…is that going to be a problem? new pistons, rings, seals, and crankshaft…used block. Of course I will get the cylinders done but is the main bearing re-bore necessary????thx

There are 6 Answers for "Is Line Boring An Engine Block Necessary Or Should You Just Replace The Bearings"

    1. bungee says:


    2. towbusiness says:

      I would get it done just to be on the safe side and to make sure everything is true. An once of prevention…..

    3. justme23005 says:

      if you are going to use it for racing, or a extremely high rpm application, then i would line bore it, if its just going in a street vehicle, then i wouldn’t bother..

    4. chevy_man_rob says:

      just me is dead on…..
      extreme rpm…do it.
      standard build…$ wasted unless there was a prob

    5. beth says:

      A good machinist can check the crank bearing bore for alignment with a straight edge. You can also tell when disassembling an engine by looking at the existing bearings and their wear pattern. If the block is straight line boring is a waste of money and a possible new source of problems if it is done incorrectly.

      If you still have the bearings marked, line them up and look at the wear, if not have the block checked by an experienced machinist who already has plenty of work.

      Not always but many times line boring is an upsale for shops looking for more profits. It isn’t needed very often.

    6. turkey says:

      if its in specs i wouldnt get it line honed. a machnist once told me that the only time the is really necissary is either A. it is out of tolerances, or B. You have new main caps installed