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bored .080 over. issues?

Discussion in 'The Garage' started by sled_dog, Feb 7, 2004.

  1. sled_dog

    sled_dog 1 ton status

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    Well would there be issues? I have a block with pistons in the back of the shop that is this way. 350 bored .080 over you get a 364. I'm thinking slap a 3.75 or 3.8" crank in there and make the biggest motor I can and really cheap at the sametime
    some vortecs on top for compression and a nice 4x4 cam for good all around power. yeah a 3.8 stroke with a bore of 4.08 would make a 397cui. That seems hard to ignore sleep time, now though so more dyno2000 runs in the morning
     
  2. big83chevy4x4

    big83chevy4x4 3/4 ton status

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    if you bore a 350 .060 over, the cylinder wall may be too thin if it is .080 over then they are deffinately to thin. you may have to have every cylinder sleeved to do it. or get an aftermafket block
     
  3. sled_dog

    sled_dog 1 ton status

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    to thin for what? getting into the waterjackets? how much you think it take to get them sleeved so I can run .080
     
  4. 87BrnRsd

    87BrnRsd 1/2 ton status

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    I wouldnt recommend boring an engine anything over .060 over. Yes, it is possible to bore an engine .080 over, and companies do make pistons this size, but at that high of a bore, cylinder wall thickness really becomes an issue. With all of those high performance mods you are planning on such a high bore, that motor will run awfully hot, and we all know what heat does to things. /forums/images/graemlins/angryfire.gif
    -Harrison
     
  5. big83chevy4x4

    big83chevy4x4 3/4 ton status

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    you need to have a certain thickness for it to hold the pressures and heat. never needed a block sleeved so i don't know how much about cost
     
  6. dustinellis

    dustinellis Registered Member

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    i wouldn't run a small block bored that much unless you filled the block,then it might run hot ,then you break it and the whole thing is trash.
     
  7. mojo-jojo

    mojo-jojo 1/2 ton status

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    I had a .060 over 350 in a 67 Nova, only had it done because that's what it took to clean up the cylinders. My machinist said that's as far as you can safely bore and that depends on the block. .080 would definetly require sleeves and block filler.
     
  8. tarussell

    tarussell 1/2 ton status

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    It would all depend on core shift and the material ( nickle content ) of the block if it would live at all . I would not run any factory SBC that much over w/o sleeving and possibly filling a portion of the block to retain cylinder wall integrity .
    I am going by memory but I think it runs around $100.00 or so to get each cylinder sleeved . You pay for what you get - not all machine shops can do a quality job of sleeving .

    Go for the extra stroke but leave the cyl. bore near 4" for longevity is my vote .
    Tom

    and remember the longer the stroke and shorter the rod the more side load is placed on the cylinder walls - don't let them get too thin or you will put an inspection hole in each cylinder . /forums/images/graemlins/eek.gif
     
  9. ntsqd

    ntsqd 1/2 ton status

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    If you're determined to do this, have the cylinders sonic mapped for core shift first. There is a minimum cyl wall thickness needed to keep the engine from running hot. Sleaves will cure hitting water, but are NOT usually thick enough for the hot running problem.

    Why not put the 3.8 crank in a 400 block ? Then you'd have a 406 on a stock bore.
     
  10. sled_dog

    sled_dog 1 ton status

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    nah I was just thinking of the best way to use what I have.
     
  11. 84_Chevy_K10

    84_Chevy_K10 Banned

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    [ QUOTE ]
    nah I was just thinking of the best way to use what I have.

    [/ QUOTE ]

    Scrap it, and use the money to buy another block. /forums/images/graemlins/thumb.gif
     
  12. bigburban383

    bigburban383 1/2 ton status

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    Screw the overbore, its not recommended. Just put your money into the heads, instead of wasting money on the overbore that may be a disaster.

    AIRFLOW = HORSEPOWER

    HEADS = AIRFLOW

    therefore

    HEADS = HORSEPOWER
     
  13. sled_dog

    sled_dog 1 ton status

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    yeah like I said in the small chamber thread, saving money for 64cc aluminum heads, preferably Edelbrock E-Tecs or standard Performers.
     

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