New Piston?

Discussion in 'Gun Building, Modifications & Repairs' started by joshkizz, Jul 18, 2012.

  1. joshkizz

    joshkizz New Member

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    Winneconne
    I currently have a jg m4 with a MOSFET and low resistance wiring installed. And I was thinking that I would like to try a li-po battery for more rof. Well I tried it and it was somewhere between 35-40 rps. I have a stock piston so it is plastic, and I was wondering if the rate of fire would strip the piston. I had a friend who tried it in a ARES g36k and it striped the piston, but he held the trigger for quite a while. So my question is this, Would a plastic piston be ok with this rps if I just shot a few rounds at a time? Or would I need to replace the piston with a metal toothed one?
     
  2. spazzticsmurff

    spazzticsmurff Member

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    phoenix
    i would buy a piston and be ready to replace it, but run it till it goes.
    what all has been done to this gun?
     

  3. Lefse

    Lefse Well-Known Member Supporting Member

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    A good plastic piston can easily handle around 35 rps if the AOE is perfect. It's also a good idea to swisscheese it and generally keep the pistons weight as low as possible, this will reduce the risk of pre-engagement and will also make life easier for your GB shell. Stock JG pistons are actually pretty strong, so if you correct the AOE and swisscheese it it should hold up well.
     
  4. joshkizz

    joshkizz New Member

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    What do you mean by "swisscheese it? I am just getting into modifications and am not familiar with all the terms.
     
  5. Lefse

    Lefse Well-Known Member Supporting Member

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    The name of the mod is pretty descriptive, you literally swisscheese the piston with a drill. You drill holes in it to remove material without reducing it's strength. You can find videos about it on youtube.
     
  6. M4Ever

    M4Ever New Member

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    Basically, swiss-cheesing a piston is the act of drilling holes in it in order to make it significantly lighter to increase the ROF. I have a buddy who's really good at doing it. I've never done it. I've HEARD ( again this is what I have heard and could be misinformation) that if improperly done, the piston will shatter and if you continue to shoot the gearbox, the shards will jam up everything and basically all goes wrong. But who knows. I do know it dramatically increase your ROF.

    Get a polycarbonate piston with a full metal teeth rack. That's what I did and it handles my 11.1 great!!
     
    Last edited: Jul 18, 2012
  7. RCV

    RCV New Member

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    I find nylon pistons to handle more stress easier. SHS to be exact. I used to swiss cheese all my pistons but I've found it doesn't do much if anything.
     
  8. M4Ever

    M4Ever New Member

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    San Antonio
    Really?! Interesting. Maybe that's with polycarbonate? Who knows. I just know its a cheap way to squeeze out a little more performance. I advise it of you can do it properly.
     
  9. RCV

    RCV New Member

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    You know those dark blue SHS pistons everybody recommends and uses are nylon right?

    I swear. This forum.
     
  10. M4Ever

    M4Ever New Member

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    San Antonio
    I'm missing what you're saying. What do you mean?
     
  11. Lefse

    Lefse Well-Known Member Supporting Member

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    In my experience, swiss cheesing is more of a reliability mod than a performance mod. It doesn't affect ROF much, but a lighter piston reduces the chance of pre-engagement, and will have a smaller impact when hitting the cylinder head, redusing the risk of cracking the fron of the gearbox. It makes sense to keep the weight down on moving parts really.

    You can actually remove a large amount of material without the piston failing, you just gotta keep enough material in critical areas and avoid making sharp corners, all the holes should have rounded edges.
     
  12. RCV

    RCV New Member

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    I completely agree but I just don't do it unless I'm passing 40 rps or maybe an m130.
     
  13. Lefse

    Lefse Well-Known Member Supporting Member

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    I have a kinda heavy trigger finger so I tend to "over-engineer" my gearboxes. Better safe than sorry you know. :D
     
  14. SilentVectorX

    SilentVectorX Member

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    San Angelo
    Possibly your best post yet. ;)

    I do agree with RCV though, swisscheesing really isn't neccesary until 35-40 RPS (if using an M120-type spring on a full stroke). I'm running at 40.3 right now, SHS M120 + SHS 15tooth Nylon + Lonex POM Piston Head, no Piston Head Bearings.
     
  15. joshkizz

    joshkizz New Member

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    Winneconne
    Thanks guys, This helps alot.