Has anyone ever modified a 400/430/455 crank to install in a N/H?

Discussion in ''Da Nailhead' started by 300sbb_overkill, Feb 11, 2019.

  1. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA

    That would mean turning the mains down to fit in a N/H block and using 400/430/455 rods and a set of custom pistons.

    I'm thinking no one has done this because taking the mains down .750"(.375" per side) may run the oil holes into the cheeks of the main journals?

    There are bearings from an International engine that would work that are for a 2.750" journal size if the housing bore in the block is opened up so there would only need .500" taken off of the main journals on the crank to fit it in a N/H block.

    The sbb 350 crank has had .500" taken off the diameter to fit into a sbb 300 block and the oil holes still work so maybe the 400/430/455 crank might also be ok with only .500" taken off the diameter?

    Not sure how good a 482 N/H(with a 425 N/H block) would run even with fully ported heads? Probably wouldn't be able to spin very many RPM above 5,000 because the heads and intake wouldn't be able to feed that many cubes very well BUT torque would be tremendous, probably in the 550 to 600 + range!(depending on cam)
     
  2. gsgtx

    gsgtx Silver Level contributor

    kenne-bell put a nailhead crank into a 455.
     
    Last edited: Feb 11, 2019
  3. gsgtx

    gsgtx Silver Level contributor

    Derek, what would the stroke be using a 455 crank in a NH
     
  4. telriv

    telriv Well-Known Member

    Better off using the forged "Nail" crank & offset grinding to increase the stroke instead of going through all the trouble & expense of making a cast 455 crank work IMHO.
     
    300sbb_overkill likes this.
  5. gsgtx

    gsgtx Silver Level contributor

    not sure how he is getting 482 ci. with a 3.90 stroke 455 crank
     
  6. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA

    The same way a 455 would get to 482 cid, by stroking the crank to a 4.050" stroke with IIRC a 4.350" bore which would require using a good 425 N/H block. This is with the 2.100" rod journal size or the 5.4L Ford rods that are 2.086" journal size.

    Stroking a N/H crank would only get to 3.880" going to a 2.00" rod journal size. Of coarse I could use the 6.495" Mitsubishi rods that have a 1.850" rod journal size and stroke it to 4.030" but I'm not sure I would want to make the journals that small even if the crank is forged. Plus the oil holes might get pushed to far in towards the edges stroking it .3990" extra? I suppose I could probably get away with machining a trench so the oil would make it closer to the center.

    Then again there is those 4340 forged BBB cranks for the Tomahawk BBB blocks with the 3.00" mains that could be turned down to 2.750" diameter to use the International bearings with that is available in various strokes.;) Doesn't have to be the cast BBB 455 crank.:cool:

    I have heard of using the N/H crank in a BBB 455 but wanted to know if in anyone did it the opposite way around?
     
    dual-quadism likes this.
  7. dual-quadism

    dual-quadism Black on Black

    I like the idea of a stroker and I may do one myself, but I would never put a 455 crank in anything. It's garbage compared to a stock forged Nailhead crank. The way to go would be just to mini-stroke a stock crank and offset it with a 2.100 or 2.00 journal. I know GSGTX did one a while back, but do not remember the final dimensions. I think the real power is in the overall package, mini-stroke, small journal, modern rods, thin ring pistons. I have the build in my head, just need to get time to start.

    Edit: I just read your last post, sorry, was in the car. Moding a forged 455 crank is a different story, but it's a $2000+ proposition. I really think all the power gains in a Nailhead are in proper camming, valvetrain, airflow and reduced friction. I am having good results with my cam grinds, I have another forged metric 401 going together now that should be a runner.
     
    Last edited: Feb 12, 2019
  8. gsgtx

    gsgtx Silver Level contributor

    done one 425 with 2.10 rod journal with longer rods and 401 with 2.20 journal with longer rods. both with billet rods.
     
    dual-quadism and 300sbb_overkill like this.
  9. PGSS

    PGSS Well-Known Member

    How was that done with big 3.25 inch mains?
     
  10. gsgtx

    gsgtx Silver Level contributor

    don't ask me lol.
    i guess with bearing spacers and messing with the caps
     
    PGSS likes this.
  11. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA

    Main spacers for the block and billet caps with the smaller bore that would keep the spacers from spinning.

    OR weld the mains to make them 3.25", being that the crank is forged it would be easier to weld it than a cast crank. Spacers and new caps would probably be the better way though?
     
    PGSS likes this.
  12. Nailhead Ronnie

    Nailhead Ronnie Life's 2 Short. Live like it.

    What are you planning Derek
     
  13. PGSS

    PGSS Well-Known Member

    I kinda???, thought of maby???, what you guys saido_O LOL!! But wow I can imagine the work involved and possible oiling issues plus the original thin wall castings????
    Good stuff guy's:)
     
  14. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA

    Nothing right now, just one of the tornado of ideas I wanted to write down while it was at the surface of the vortex.
     
  15. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA

    Piece of cake with the right equipment and know how.;)
     
  16. gsgtx

    gsgtx Silver Level contributor

    with the nailhead crank 462 ci with the 455 crank 482. so we are talking 20 ci. not sure it's worth the money and trouble. Derek, am glad your thinking about ideals for the nailhead. :)
     
    300sbb_overkill likes this.
  17. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA


    If the N/H has the same cam to crank centerline as the BBB platform then it should handle the same 4.400" stroke the the factory block BBBs can?o_O

    If so, with the 425 bored to 4.350" and one of those forged cranks with a 4.400" stroke would be able to get a N/H to 523 cid! That's an extra 98 cubes, worth it yet?;)

    Of coarse with the best N/H ported heads I recall IIRC only flowed around 260 max intake CFM! Even @ that flow rate the RPM would probably be done under 5,000 with that many cubes, but imagine the torque that thing would make!:eek:

    Maybe Ken Betts will make some aluminum N/H race heads that flow over 300 intake CFM to feed a 523 cid N/H?:cool:
     
    Julian and gsgtx like this.
  18. gsgtx

    gsgtx Silver Level contributor

    now with 500 or more cid i would think about that. wonder if it would work.
     
    300sbb_overkill likes this.
  19. PGSS

    PGSS Well-Known Member

    523 cubic inches of NailHead torque..:D. What a fun 1000 ft ride that would be:)
    On another note when I posted yesterday I played 455 on the MA daily number... It came out today:( Always me:rolleyes:
     
    300sbb_overkill likes this.
  20. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA

    Ahhh man, so close yet so far away!
     

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