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QLD WTB - FZR250R 3LN1 - 3LN3 engine

Discussion in 'WANTED' started by fnq_fzr, Nov 18, 2020.

  1. fnq_fzr

    fnq_fzr Active Member

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    Hi All,

    Chasing a FZR250R 3LN1 - 3LN3 engine to replace the track bike engine. Require head, barrels and bottom end. Everything else will come from the track bike. Australia only please. Queensland would be great. Prepared to buy complete bike at right price.
    Turn 3 Morgan Park.jpg
     
  2. ruckusman

    ruckusman White Mans Magic Master Premium Member Dirty Wheel Club

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    Out of interest, what went wrong?

    I know both @gregt and @Mike Green have some advanced insights on preparing the cranks in their various threads
     
  3. Andych

    Andych Moderator Staff Member Premium Member Contributing Member Dirty Wheel Club

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    I have a Zeal that you can have.... all you would need to do is pay for the transport from Sydney.....not sure how the engines differ though.
    It does have 100,000 km on it though :)
     
  4. fnq_fzr

    fnq_fzr Active Member

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    Bottom end let go 'again'!! I will take a look at the threads you mention. I have also been told of some other 'tricks' to ensure better oil delivery..

    Thanks @ruckusman.
     
  5. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

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    *Kawasaki ZXR250C *Yamaha FZR250R 3LN1 *Yamaha FZR400 *Triumph Bonneville 750 T140V *Triumph Daytona 675 *Triumph Tiger 800XC
  6. ruckusman

    ruckusman White Mans Magic Master Premium Member Dirty Wheel Club

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    Yes, I'm not certain where the information lives - @Mike Green also has a large thread on Kiwi bikers I think it is about his turbo half and I know both Mike and @gregt have discussed radiusing the oil feeds to the mains and big ends to improve flow - but I don't want to misquote them and steer you wrong

    There's a really serious depth of knowledge between those two

    Now one thing which I cannot find the original source for is putting a shim in the oil pressure bypass - it was related to FZR400's because the oil pressure bypass is very close to the oil pressure at high RPM

    Wow I just found it, I was searching for oil pressure bypass, the correct search term was oil pressure relief

    Mentions the oil pressure at peak RPM being close to the relief valve working pressure
    https://bdkraceeng.co.uk/tc/products.php?357&sid=5ekskbctc0oqduumtsep0unk66

    Mention of using the shim in an FZR400
    https://www.gtamotorcycle.com/xf/threads/fzr400-winter-overhaul.178050/page-4
     
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  7. 19pJoshrulz

    19pJoshrulz Active Member

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    i have a recently blown engine that i don't need, crank would need a linish on one journal, barrel is good, head has oil starved cam journals, cases are good.
     
  8. gregt

    gregt Well-Known Member Premium Member

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    I've come to the opinion that there's not too much wrong with the oil pressure in these engines.
    Where they and a lot of others too fall down is the finishing of the cranks.

    Production times don't permit inspection and rectification of poor oil hole finishing IMO.
    I now routinely radius the oil holes in all crank journals - mains and big ends.
    I doubt if it improves flow to any significant extent - but it avoids the shearing of the oil film which
    occurs when there is a sharp edge left on the hole.

    Shear the oil film and it results in metal to metal contact - and bang!
     
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  9. driftwood

    driftwood Well-Known Member

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    Just scored a pair of 3LN3 engines, 1 in bits & has no valves. Looks OK.
    Know anyone in Melb who'd check it out to see if any good to you?
     

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