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Thread: JDM QR20 pistons in QR25DE

  1. #1

    JDM QR20 pistons in QR25DE

    Last night and into this morning Will from WRP and my self swapped the JDM QR20DE pistons into his 02 SE-R. they fit perfectly but ran into what we believe is a fuel delivery issue that he is working on today, it was 4am and I called it night when we coulnt get it stated last night.

    Stock QR25

    JDM QR20DE pistons installed

  2. #2
    So the engines share the same bore?

    Do you have an pics of the difference?
    Hers - 2K Maxima SE Auto - Satin Blue Pearl
    Theirs - 2k2 G20 Sport - Merlot Pearl
    His - 68 Plymouth Sport Fury
    Seek or not, God is there. - Carl Jung

  3. #3
    no pics of the differeace on my camera. but the are the same size. the QR20 has a shorter bore but everything fit well. just not sure why it was not getting fuel

  4. #4
    Ok, I go it. The QR family of variants share the same 89 mm bore. The QR20DD has a 80.3mm stroke
    QR25DE has a 100 mm stroke

    Longer stroke = more torque

    But my question is: Are there any differences in overall piston hight? What are the gains/benefits?

    Or are you just doing this because you can? :D
    Hers - 2K Maxima SE Auto - Satin Blue Pearl
    Theirs - 2k2 G20 Sport - Merlot Pearl
    His - 68 Plymouth Sport Fury
    Seek or not, God is there. - Carl Jung

  5. #5
    basicly doing from 9.5 to 1 to 12 to 1 compresion the piston it self is domed on the top but where the rod joins it creats an equal lenth stoke that the stock one had so it is still a 2.5. and yes basicly becasue we could

  6. #6
    OK, high-compression 2.5.... cool!

    Does it run yet?
    Hers - 2K Maxima SE Auto - Satin Blue Pearl
    Theirs - 2k2 G20 Sport - Merlot Pearl
    His - 68 Plymouth Sport Fury
    Seek or not, God is there. - Carl Jung

  7. #7
    as of right now no, was not a fuel issues aperntly his brand new block was a re man so it was slight overbore so need to re ring the pistons

  8. #8
    correct and the qr25 have the same bore, but the compression changes if you drop the 20 pistons in - it goes to a 12.1 compression, which is nice for some power -

    we are expecting to see over 230 whp in the setup
    Thanks!
    William Perdigon

  9. #9

    Question

    Where do you get the pistons? I have been reading about this and would like to try this as opposed to using f/i. I don't need much more power and think this would be perfect. Email me the specifics including prices if you have the time.

  10. #10
    Senior Administrator palmerwmd's Avatar
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    I think Will aka wrp has been possibly working on a kit.

    Don't know if its available yet, or if his testing is complete or if the ever intends ot market it (just imagine the complaints for something that needs to be tuned <perfect> and some folks start blowing engines...!)

    But he has a Black SPECV running the 12.x compression that he uses as a daily.


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  11. #11
    Quote Originally Posted by palmerwmd

    But he has a Black SPECV running the 12.x compression that he uses as a daily.
    don't forget it also has the meth injection, but overall, that thing is pretty quick, too...
    it's frez-nee....not frenzy

  12. #12

  13. #13
    these pistons are only available from japan, i got them directly from my source at nissan motorsports. if/when i do build a kit for this it will be a solution for the n.a setups a lot of people like over it-

    check out nissan sport magazine as well for an article on this, we are in the current issue for the diy section on it and about what we did to make it work
    Thanks!
    William Perdigon

  14. #14
    Thanks for the info. I have read the Nissan Sport article and watched your youtube video. Email me something on a resource for the pistons, my mechanic thinks this sounds like fun nad I have no problem being one of the first to try it when you get it tuned right. And thanks for the welcome, I am also on myspecv, nissanforums, and b15 sentra. This mod shouldn't scare anyone since the f/i folks have some tuning issues too. Please keep me updated. Thanks.

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