Lightening a stock 440 crank

Big Block A body Tech

  1. cnantz

    cnantz New Member

    Messages:
    4
    Likes Received:
    0
    Joined:
    Jan 29, 2011
    Location:
    western kentucky
    Local Time:
    3:51 PM
    I am planning to do some grinding and cleaning up on a stock crank. I don’t wanna remove so much that Mallory needs to be added but will do some weighing and comparing of stock vs the rods, pistons, rings, rod bearings, pins I’ll be running. Question..... when chamfering oil holes how aggressive should a person get? Length of chamfer? How much to chamfer the leading edge vs the trailing edge of the oil hole? What’s your experience?
     
  2. dukeboy_318

    dukeboy_318 Our Lives, Our Fortunes and Our Sacred Honor. FABO Gold Member

    Messages:
    31,203
    Likes Received:
    10452
    Joined:
    Jan 19, 2007
    Location:
    la la land
    Local Time:
    4:51 PM
    Just how are you going to be "grinding" on this thing? Are you doing this yourself or paying someone?
     
  3. cnantz

    cnantz New Member

    Messages:
    4
    Likes Received:
    0
    Joined:
    Jan 29, 2011
    Location:
    western kentucky
    Local Time:
    3:51 PM
    well I was planning on using a die grinder with a few carbide burrs, file and a 4 inch grinder. When chamfering the oiling holes I was gonna use a stone or maybe a sanding roll/tootsie roll. I’m not going to grind the mains nor rod journals. If that is what your thinking. Just going to remove a little excess material in uncrucial spots, radius and lighten the counter weights. I figure if the machine shop is going to have to balance it by drill holes deeper I might as well remove material before it gets to the machine shop. However I mainly am concerned with chamfering the oil holes. How “big” To make them?
     
  4. 72Dart6pack

    72Dart6pack Harder Better Faster Stronger.

    Messages:
    2,873
    Likes Received:
    1903
    Joined:
    Feb 1, 2016
    Location:
    Roseville Michigan
    Local Time:
    4:51 PM
    Get a aluminum crank. They are super light. :)
     
  5. cnantz

    cnantz New Member

    Messages:
    4
    Likes Received:
    0
    Joined:
    Jan 29, 2011
    Location:
    western kentucky
    Local Time:
    3:51 PM
    Now that would leave with nothing to do
     
  6. oldkimmer

    oldkimmer FABO Gold Member FABO Gold Member

    Messages:
    10,443
    Likes Received:
    1290
    Joined:
    Nov 11, 2006
    Location:
    Kindersley, Saskatchewan,
    Local Time:
    3:51 PM
    I had a guy with a laithe turn down the counter weights on my 440 crank.120 thou. If u don’t turn the weights down u will be drilling big holes in the crank. My thoughts were if I didn’t get enough metal taken off the weights that I would knife edge them some. My Molnar rods and Diamond pistons are a lot lighter. I would check with the guy turning ur crank how much to chamfer the oil holes or even if he recommends it. Kim
     
    • Like Like x 1
    • pishta

      pishta I know I'm right....

      Messages:
      14,037
      Likes Received:
      3721
      Joined:
      Oct 13, 2004
      Location:
      Tustin, CA
      Local Time:
      1:51 PM
      Chamfer is not critical dimensions, just knock the edges off the hole with a 45 countersink. you really need to get the rods and pistons weighed on a crank balancer to assay how much you can remove. AND all the weights are critically dimensioned from the throws. Its a balancing act on removing weight and then adding mallory in the end at $70 a slug. Id let the crank shop do it on their drill press as your going to get it balanced anyway.
       
      • Agree Agree x 1
      • qkcuda

        qkcuda Well-Known Member

        Messages:
        928
        Likes Received:
        493
        Joined:
        Mar 6, 2013
        Location:
        Jarvis, Ontario
        Local Time:
        4:51 PM
        My pistons were super light (500 grams) so we turned down the counterweights. They took too much off and had to add $300.00 of Mallory!
         
      • hangn0ut

        hangn0ut Well-Known Member

        Messages:
        744
        Likes Received:
        118
        Joined:
        Dec 3, 2012
        Location:
        rialto.ca.
        Local Time:
        1:51 PM
        Why not weld some nice beads on those undersize counterweights and save most of that mallory money?
         
      • EchoSixMike

        EchoSixMike Well-Known Member

        Messages:
        257
        Likes Received:
        81
        Joined:
        Nov 20, 2013
        Location:
        Chicago
        Local Time:
        3:51 PM
        Oil passages, just a light chamfer, gentle touch there. With the angle grinder, it's all knife edging and grinding out parting lines and sharp edges. Again, gentle touch unless you're sending it out to be turned, an "opps" gets expensive fast.

        Remember that bobweight is like torque; the greater the working radius, the more effective it is. Removing weight with a lathe is very effective, it's at maximum radius. Grinding and knife edging doesn't give as great a return, since you're working at reduced radius. So if you remove say 400gm of actual metal, it won't have nearly 400gm of bobweight reduction, depending on where the metal was taken from. S/F....Ken M
         
        • Like Like x 1
        1. This site uses cookies to help personalize content, tailor your experience and to keep you logged in if you register.
          By continuing to use this site, you are consenting to our use of cookies.