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  1. #1

    Big Bore questions

    First -
    what are the biggest cast size pistons you can buy ?
    Who what brand ??

    Second -
    Is the Group K 87mm kit Flat top ? (my guess is Kawasaki design pistons)
    Riva's 86 and 86.5mm kits look like Kawasaki style cut.

    I have a set of cylinders I'm going to be boring to port then plate.

    thanks,


  2. #2
    OCFZR's Avatar
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    Hi,

    I have the 91 oct GK 1390 kit. The pistons are very close to being flat. This is an excellent kit to say the least!

  3. #3
    ABBOTT's Avatar
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    You have a Private Message.

  4. #4
    87mm is the way to go if you go big bore those pistons would come from GroupK.
    84mm would be a factory OEM or Pro-X Piston

    When going BB keep in mind that you can not go back to a smaller size unless you sleeve the cylinder. Make sure that those larger aftermarket pistons are available for years to come.

    GroupK or Lowell Horning can point you in the right direction.

  5. #5
    All hail the Chief! fullboogie's Avatar
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    There's also port timing issues when you overbore, so make sure your engine guy knows his stuff about how to compensate for this with porting.

  6. #6

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    I herd rumors of bigger pistons than the 87 mm ones

  7. #7
    All hail the Chief! fullboogie's Avatar
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    Quote Originally Posted by 05GP1400R
    I herd rumors of bigger pistons than the 87 mm ones
    Well, just ask Abbott. Maybe he can PM you some info.

  8. #8
    just GOT TO DO IT! great lakes gpr 1200's Avatar
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    Talking

    Quote Originally Posted by Fercho
    87mm is the way to go if you go big bore those pistons would come from GroupK.
    84mm would be a factory OEM or Pro-X Piston

    When going BB keep in mind that you can not go back to a smaller size unless you sleeve the cylinder. Make sure that those larger aftermarket pistons are available for years to come.

    GroupK or Lowell Horning can point you in the right direction.
    HE SAID IT !

  9. #9
    Thanks to all that Pm'd me.

  10. #10

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    big big bb question

    Iwould like to make a very bigbig bore some where around 1600 cc or 91 mm seedoo piston can this happen and does anyone here know if the 1200 cylinder will work or are 1300 cylinder better does any have a link to group k...

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