Question on nitro bore sleeves 4.187 bore

Discussion in 'PSI Superchargers Tech Questions' started by John byob, Dec 12, 2021.

  1. John byob

    John byob Member

    Joined:
    Apr 13, 2019
    Messages:
    226
    Likes Received:
    2
    hi first what is the largest u can over bore a 4.187 sleeve? Next is what is the most compression you can make with a piston that is in a bore size with buying custom pistons. Stroke is 3.750 bore 4.187 bae fuel heads 180cc and not sure what rod lenght yet. Thx guys
     
    #1
  2. John byob

    John byob Member

    Joined:
    Apr 13, 2019
    Messages:
    226
    Likes Received:
    2
    . Ohh ok have t check rob, but what about the compression question? Thx
     
    #2
  3. John byob

    John byob Member

    Joined:
    Apr 13, 2019
    Messages:
    226
    Likes Received:
    2
    I have 4.490 OD sleeve. In a 4.187 bore, what can it be bored out to? If at all thx rob
     
    #3
  4. John byob

    John byob Member

    Joined:
    Apr 13, 2019
    Messages:
    226
    Likes Received:
    2
    on the sleeves I took that measurement. Can that sleeve be bored? If yes what’s the max? I need min 4:250! PS the newer top fuel blocks do they all come with 4.550 sleeves? Say a John force block?
     
    #4
  5. John byob

    John byob Member

    Joined:
    Apr 13, 2019
    Messages:
    226
    Likes Received:
    2
    PS not sure what block the 4.90 sleeves came frm?
     
    #5
  6. John byob

    John byob Member

    Joined:
    Apr 13, 2019
    Messages:
    226
    Likes Received:
    2
    have older KB dry and newer KB wet
    But have two older 2000 Brad billet too. But will measure the registers after work thx rob
     
    #6
  7. Mike Kern

    Mike Kern Member

    Joined:
    Aug 17, 2010
    Messages:
    51
    Likes Received:
    10
    Go to the Darton website and check their sleeve sizes. There are all sorts of different sleeve sizes available, so it depends on your block and ultimately what wall thickness you will be left with. You'll most likely be better served buying new sleeves if the wall thickness is getting too thin. Lastly, you can always overbore the block to run a thicker wall sleeve. Structurally this is the more sound way to go if weight is not of concern.
     
    #7
  8. John byob

    John byob Member

    Joined:
    Apr 13, 2019
    Messages:
    226
    Likes Received:
    2
    oh fr sure, but I got a lot of 4.187 sleeves. And can get 4.250 bore high compression pistons fr my needs. If I can get away with that over bore? Thx
     
    #8
  9. Dave Koehler

    Dave Koehler Member

    Joined:
    Sep 10, 2004
    Messages:
    443
    Likes Received:
    14
    You are only talking about .063 over or .0315 per side.
     
    #9
  10. Mike Kern

    Mike Kern Member

    Joined:
    Aug 17, 2010
    Messages:
    51
    Likes Received:
    10
    Per my calcs, even with the thinnest wall 4.187 bore sleeve, you will be at .120" wall at 4.250 bore. That's as thin as Darton goes on a sleeve except for their big bore, short deck alcohol stuff where they go down to .104" wall. You can probably get away with it if you keep everything squared up. You just can cry about it if one fails.
     
    #10
  11. John byob

    John byob Member

    Joined:
    Apr 13, 2019
    Messages:
    226
    Likes Received:
    2
    . Thx dave
     
    #11
  12. John byob

    John byob Member

    Joined:
    Apr 13, 2019
    Messages:
    226
    Likes Received:
    2
    it will only be fr injection only, and small stroke. Non boosted.
     
    #12
  13. John byob

    John byob Member

    Joined:
    Apr 13, 2019
    Messages:
    226
    Likes Received:
    2
    and that’s on their blown short deck alcohol engine?
     
    #13
  14. John byob

    John byob Member

    Joined:
    Apr 13, 2019
    Messages:
    226
    Likes Received:
    2
    My sleeve thickness is .150 and need to bore them to 4.250, so I am left with .083 thick? Not sure if that’s good enough to run a injection motor?
     
    #14
  15. John byob

    John byob Member

    Joined:
    Apr 13, 2019
    Messages:
    226
    Likes Received:
    2
    yes that’s sound advice but not making a ton of hp. Un blown 900, blown if possible 1200?
     
    #15

Share This Page