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Gsr overbore

Discussion in 'Engine Building' started by Goldberg, Apr 19, 2004.

  1. Goldberg

    Goldberg Member

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    Ok so i plan on a gsr engine and what i want to know is since i want to keep it as reliable as possbile, but still build it the way i want. Is a 85 mm decent could i run a little more? Cause i was looking at the over bore thread and he has it all the way to 87. So basically is 85mm good enough could i run more or would it be unreliable?
     
  2. 97CTR

    97CTR Senior Member

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    Do you plan on sleeving the block? Because that is the only way you can bore the cylinder to 85mm. On a stock block the most that you would want to go would be 82mm.
     
  3. D See 2

    D See 2 Senior Member

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    honda only recommends a maximum overbore of .25mm, but do as you wish.

    [​IMG]
     
  4. handlebarsfsr

    handlebarsfsr Senior Member

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    the b20 runs an 84mm bore on stock block sleeves, so i dont think that would be an unreasonable overbore. pushing beyond that is gonna start weakening cylinder walls, and probably isnt a good idea without a sleeved block. but if your planning on spending the $ to rebuild the whole bottom end, the 800 bucks it costs to get a good sleeving and boring job is definitely worth it.
     
  5. D See 2

    D See 2 Senior Member

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    ummm, the b20 has completely different sleeves than the gsr does. try taking a stock gsr sleeve to 84mm and see how much material, if any, is left.
     
  6. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    :withstupid:

    Good luck going to 84mm on a stock GSR sleeve.

    On the original question- if you resleeve your block, you can go to 85mm with no problems on the street. 85.5mm is as far as I would go on a street build- 84.5mm max if you're boosting.
     
  7. Goldberg

    Goldberg Member

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    Ok yes i am planning on spending the money to resleeve it, and rods pistions everything. I am building and all motor gsr. So 85 takes it then.
     
  8. D See 2

    D See 2 Senior Member

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    sounds awesome. be sure to get us some pics of the build.
     
  9. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    Cool. Good luck!
     
  10. 97CTR

    97CTR Senior Member

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    Yes you can go with an 85mm bore. But do you want to be able to rebuild it if you have some damage? I would go with an 84 or 84.5 that way if you have some cylinder wall damage you have the material to work with to bore it out again.
     
  11. D See 2

    D See 2 Senior Member

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    exactly, its called planning ahead.
     
  12. Goldberg

    Goldberg Member

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    ok cool thanks guys when i get the block redone i will hopefullly get some pics up.
     
  13. Goldberg

    Goldberg Member

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    Now for another Q, i am reading all these post about using ls rods and stuff etc. Would it be better to keep it aftermarket gsr spec or something different?
     
  14. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    Using LS rods in a longer stroke application or using LS rods to be stronger? If you're reading about using LS rods in a slightly stroked application, you have to use the LS crank with them. The GSR pistons won't mount up exactly on the LS rods- the rods are different thicknesses. You'll have to go to custom pistons for that, if you don't want to modify the stock LS rods.

    If you're talking about more strength, go aftermarket. The people swapping in LS rods for more block strength are the D block guys. LS rods just happen to be the same length as the D16 rods, and have the same journal size on the crank as the D16, so lots of budget D series turbo guys like to drop them in. This doesn't work for your B block. Go aftermarket for stronger rods on your GSR.
     
  15. Goldberg

    Goldberg Member

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    Ok so just go all after market gsr everything? Aight cooo. Cant wait to run when i eventually get finished. See what kinda numbers i can get outa a all motor gsr.
     
  16. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    You can make 200whp+ easy with all aftermarket internals on a GSR block.
     
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