buick oil modification drill bit

Discussion in 'Parts for sale' started by FLAME ORANGE GS, Sep 9, 2021.


    FLAME ORANGE GS Founders Club Member

    i have a 9/16 drill bit to drill out the oil passage on a buick block. also i had a machinist friend make a cutter with a 3/8 guide so you can get the hole stated correctly. it cant wander because you can get the hole about half way following the original hole. this really worked great and i didnt worry about the bit wandering off and putting a hole in my original block.

    i have no use for it now so if someone wants it i'll do $50 shipped anywhere in the 48 states.

    Attached Files:

  2. rus

    rus Well-Known Member


    FLAME ORANGE GS Founders Club Member

    this bit drilled one hole only , still sharp.
    knucklebusted likes this.
  4. bigdavesstg1

    bigdavesstg1 Well-Known Member

    Next inline

    FLAME ORANGE GS Founders Club Member

    you guys might want to pass this around. you should only need it once!
  6. 12lives

    12lives You die once. You live every day.

    Can you find out where he got the starter bit?
  7. stagedgs

    stagedgs 1967 GS400

    The pilot bit is a good idea for this application, but I wonder if he should be considering talking to a lawyer about patenting this. Your machinist friend may be sorry he didn't down the road. A piloted drill bit is not a new idea, but for this application it may be.

    I used to work with a guy that that years ago looked at Harley's Big Twin 5speed transmission and figured out a way to add an additional (overdrive) gear. As far as I know he didn't patent the idea and of course everyone copied it. Even Harley finally added a sixth gear to their Big Twin product line. At the time Bert opened up his own successful motorcycle transmission business, but the money he could have made off of royalties alone....
    .....just sayin'.
  8. TheEternalDance

    TheEternalDance Well-Known Member

    Like that idea quite a bit, actually! I have two blocks I'd like to 'borrow' this for (I'll buy it, but then would likely be selling it, like this) - count me inline if it makes it to me.
  9. 12lives

    12lives You die once. You live every day.

  10. Jesse Tackett

    Jesse Tackett Well-Known Member

    I'd like to get in line on this as well. jess in ky
  11. Bens99gtp

    Bens99gtp Well-Known Member

    Should.....till you put the extra sight glass that never seals up in one......lol
    Dano likes this.

    FLAME ORANGE GS Founders Club Member


    FLAME ORANGE GS Founders Club Member

    i think he just modified a commercially available tool. it has markings on it. i will post them tomorrow.
    Dano likes this.
  14. Dano

    Dano Platinum Level Contributor

    Not sure patenting it is really necessary in this case but would your machinist friend be interested in making some of the pilots? I'd buy one. Maybe make them in 5/8" too.

    I'm not sure but is enlargement to 5/8" not possible or just not deemed necessary on the 350?

    FLAME ORANGE GS Founders Club Member

    heres whats stamped on the tool.
    putnam tool co.
    3/8 x 9/16
    cs24 m-2

    dano - it just looked really scary to go to 5/8 . ta says they do it but to me it wasnt worth the risk on my original 350 block.

    i will reach out to my friend and see if he can get more or you guys can try the internet?
  16. Dano

    Dano Platinum Level Contributor

    Thanks! I searched that # & didn't come up w/anything but probably could find it in a tooling catalog.

    I coukd probably even do the mod myself but was thinking if it was something he modified maybe he'd want to set up and make a bunch to sell on here. Doubt anyone is getting rich off it but...

    I agree on the orig. block. I have the 2 orig. 350's for my GS's which I'm planning on m/l stock builds but would go 9/16" on them & then 5/8" on the subsequent higher HP builds so if your friend wants to make them, I'd take one of each.
    knucklebusted likes this.
  17. bigdavesstg1

    bigdavesstg1 Well-Known Member

    Did you sell the drill bits???

    FLAME ORANGE GS Founders Club Member

    no, the big bit i bought from TA i believe.
  19. knucklebusted

    knucklebusted Well-Known Member

    Back in the day, they told me 9/16" was as big as you wanted to go a 455 block with the small passage. It was still much better than the old passage.

    On my original 71 350, I drilled mine from 7/16" to 1/2" and it worried me. You might get 9/16" if you are really lucky but I'd bet going 5/8" on a 350 will be a very risky event. TA sells a 1/2" pickup for the 350.

    If you try, please document it for future readers to duplicate.
  20. Mart

    Mart Gold level member

    Guys, I don't think anything over 9/16" is needed. I have all the o/p I want at 9/16" up to 7k+ using 5/8" pickup.
    Don't re-invent the wheel....
    knucklebusted likes this.

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