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If I pressurize the mains?

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  • If I pressurize the mains?

    I have been sorta developing a pressurizing for the main bearings that I have confidence will work. What I am wondering is, do I really need to drill the crank and pressure oil the rods?

    I know, I know, you are going to say, "why go half way?", well, on my extremely limited budget I can't pay for a drilled crank, nor can I do the job myself without the fixtures and mill the size needed.

    Now, since I am not above begging for charity, and there hasn't been a single donation to my FundMe account, I will take any and all gifts to my Paypal account at

    So, how about not dwelling on my poverty and answer the question, do I really need to drill the crank? I will only be running about 35# of pressure to the crank bearings, and the popoff will be in the valve chamber so all the extra oil will be going too the original path, so I doubt there will be a lack of oil anywhere else. I just need to know that the original oiling to the rods will be sufficient I guess.

    All the bearings will be babbit. No inserts.
    "We do not stop playing because we grow old;
    We grow old because we stop playing ...
    NEVER Be The First To Get Old!" Pilfered from the MAFC SA Newsletter


    Just how long a minute is, depends on which side of the bathroom door you are on!

    If you are not the lead dog, the view is always the same!

  • #2
    I wouldn't drill the crank. Dipper works fine.


    • #3
      Folks that were driving very early Model T's were pondering a similar situation. They were relying on only splash, drip, and mist to lube the mains and rods. Even though the system worked (mostly), they wanted to do more. "If only we could somehow 'dip' the rods too, then we could be certain the rods would be oiled sufficiently", they thought. So they worked and worked on the problem and...success, dippers worked!
      Last edited by Ayyy; 05-17-2018, 12:37 AM.


      • #4
        Wiz, you going to have 3 pop offs or just 1 in the valve chamber ? They can tend to malfunction or would you run through the filter after the mains with just a restriction device ? Don't listen to me I'm always wrong and since this Model AA has come into my life, I also need a fund me thing !! Pat


        • DaWizard
          DaWizard commented
          Editing a comment
          Pat, just one and I have already tested and made sure it was set for 35#

        • pAAt
          pAAt commented
          Editing a comment
          Could you give me a diagram of what you are planning to do Wiz ? Kinda like Ayyy, but I got plenty of room in my brain since nothing sticks anymore !!

        • DaWizard
          DaWizard commented
          Editing a comment
          Pat, I will go ya one better and post pictures of the way I am going at it. It will need to wait until after next week as I am pulling the current engine to change the tranny and tighten up the crank and rod bearings. Also do some painting of engine.

        • pAAt
          pAAt commented
          Editing a comment
          That would be awesome Wiz !! Kinda like this engine tinkering thing you do, but is hard to follow you sometimes.

      • #5
        I've never drilled a crank, forged or cast. Can a crank be drilled at home with basic tools? I know normally its done with precision machining, but does it need to be? Now this question is floating around in my head like a worn out song. Ain't got no more room in my head!
        Last edited by Ayyy; 05-17-2018, 12:49 AM.


        • DaWizard
          DaWizard commented
          Editing a comment
          Alex, it requires some pretty precision drilling. I believe the angle is 34º and I doubt you could do it at home with a hand drill, you also have to mill a flat because no matter what drill you use, they will not start on an angle, you need a flat spot to start a drill.

        • Ayyy
          Ayyy commented
          Editing a comment
          I'm sure you're right JC. I'm at a disadvantage since I don't have a crank available to look at. If you need to drill at such a specific angle, then doing it by hand would not be possible of course. I sympathize.

      • #6
        Could you build a guide that would hold the drill bit at the correct angle and location on the journal. Thinking something like the head bolt removal guide.....
        only more complicated

        "Beer is proof that God loves us and wants us to be happy." -Ben Franklin


        • DaWizard
          DaWizard commented
          Editing a comment
          Like I mentioned above, it is not hard to drill, it is hard to get the right angle and you MUST start the drill on a flat surface. Because a drill has an angled cutting surface it will just skip across and off the part.

          Try to drill a hole in a spare piece of pipe without first placing a flat on it. Now try to do the same thing on an angle.

      • #7
        I have done it both ways. My over head that I use at hill climbs has a drilled crank. But if you do it the wrong way it makes the crank weak at the rod journal.
        You really do not need a drilled crank for the rpm you will be running. Dippers work really good. Chev 6's used them for many years. I use to race them and never lost a rod.


        • #8
          I can't help J C on the crank oil subject, but this oiling the engine got me to thinking of a money maker for someone: you know those unloading stations, where the driver drove up on a ramp, and the ramp would turn a 180 degree, and dump their load, then right them again, and off they went? Well, before each Model A trip, one just drive to one of these stations, and do the loop-T-loo, and your fully oiled.


          • DaWizard
            DaWizard commented
            Editing a comment
            Sunny, if you look at the small return tube off the rear main cap, you will find some that have a ball bearing crimped into the end to stop the draining of the pan when the trucks were raised to dump a load. I don't think a twist would satisfy the need for oiling long term.

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