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Thread: Riva cylinders

  1. #1
    cmherrera's Avatar
    Join Date
    Dec 2007

    Riva cylinders

    I have Riva ported cylinders and I'm thinking of having some work done to it. It has sleeves and ran flat top pistons. I dont want to run flat top pistons, and if it had alredy been ported, can it be redone? I want big bore.I keep hearing Lowell's name. He is the man for boring and porting.
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  2. #2
    Im sure Lowell can answer all your questions in detail. Clik on his link on my signature for contact info.. Ross

  3. #3

    Join Date
    May 2006
    Okinawa Japan
    Let us know what he tells you please. I'd think that since the cylinders have been decked for flat tops, you'll be stuck with using flat tops unless there is someone out there who is making shorter pistons that you can now use in these shorter cylinders.

    But I am curious to know for sure - I have a set of Riva/Farthing ported race gas cylinders collecting dust on my shelves cause race gas is too expensive for me in Japan. If they can be bored to BB, I might consider that and going BB on my SS GPR..

    Keep us posted please...thanks,


  4. #4

    Join Date
    Jan 2006
    Taylor, MI 48180


    How big are you looking to go?
    I PMed you to offer some help, but you didn't reply?
    Travis (TCR)

  5. #5
    You can buy Kawasaki Flattops all the way to 90mm - Fennec of Japan has 89-89.5-90mm in stock

    But you need to check which big bore flat top sleeves were used. I think Riva used the 90mm sleeves so the biggest would be around 85.4mm GroupK's
    Dont know anyone else making bigpin 86-88.5mm flattops.

    If you run the small pin rods you can get anything you want to 80-94mm

  6. #6
    cmherrera's Avatar
    Join Date
    Dec 2007
    the sleeves are only 87mm

  7. #7

    Join Date
    Aug 2007
    Rotterdam,NY & Moneta, VA
    why not try and trade them to someone looking for that setup

  8. #8
    In the 87mm sleeves I've run 82.7mm Kawasaki OEM SXR pistons and can go to Wiseco 84mm pistons Kawasaki

  9. #9
    cmherrera's Avatar
    Join Date
    Dec 2007
    I Have To Replace The Crankshaft, So What Pin Size Should I Go With? I ALSO WANT TO BORE IT OUT TO 84MM. DO I HAVE TO SEND THE CYLINDERS WITH THE GAS VALVES?
    Last edited by cmherrera; 01-03-2008 at 02:01 AM.

  10. #10
    Well if you go small pin you dont have the smaller size ranges of the big pin.
    Big Pin rebuilt crank will open the door for the available pistons on this site through 90mm.

    If you go small pin - Honda CR500 also can go way into the 90's in piston size but your going to have to resleeve or recylinder and figure out the right cylinder height based on the new pistons. (Miller Wiseco's bigbore XPL)

    Some of the fastest GPR's (CC racing) and most HP used CR500 rods and Kawasaki small pin oem and/or Wiseco pistons.

    Easiest and cheapest would be to rebuild the crank with existing or new GPR rods and get the Wiseco 84mm flat-tops. Make sure the person boring the sleeve gets it right because your getting real thin at .060" wall.
    You can go 83.5mm ProX SXR pistons.... and keep .080" wall

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