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1 piston ring or 2 piston ring whats better ?

Discussion in 'Chainsaw' started by glock37, Nov 3, 2011.

  1. glock37

    glock37 Addicted to ArboristSite

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    I,ve been looking around on e-bay and there a few makers of pistons going to 1 ring pistons compared to 2 ring pistons saying

    it makes more compression ?

    whats the story here ?

    Mike
     
  2. blsnelling

    blsnelling Site Sponsor

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    Makes very little difference in compression.
     
  3. Andyshine77

    Andyshine77 Addicted to ArboristSite

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    Haven't seen any compression or durability issues whatsoever. Some say two rings are better for heat dissipation, and they keep compression up over the long haul, but I haven't seen this. Some of the most durable old saws only had one ring. This question has come up many times on the site, and my conclusion is it doesn't make a noticeable difference in a normal stock work saw.
     
    Last edited: Nov 3, 2011
  4. hamish

    hamish Addicted to ArboristSite

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    Basically i boils down to the fact that 1 piston ring is better than 2, as you will only need to buy one ring when you freshen your saw up!
     
  5. Andyshine77

    Andyshine77 Addicted to ArboristSite

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    Well true, but most chainsaw rings are very, very cheap.
     
  6. glock37

    glock37 Addicted to ArboristSite

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    wouldnt 2 rings help center the piston in cyl. better than 1 ?

    theres a 041 piston with 1 ring on ebay its a earlier type but why are all later versions 2 rings ?

    im just asking to make sense of things
     
  7. Log Hogger

    Log Hogger ArboristSite Operative

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    Less friction with one ring. I don't know what the practical implications are for the slight difference in friction between one or two rings.
     
  8. nandoz

    nandoz 15 men on a dead mans chest

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    Manufacturers like to sell parts.
     
  9. blsnelling

    blsnelling Site Sponsor

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    It's significant.
     
  10. Andyshine77

    Andyshine77 Addicted to ArboristSite

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    With chainsaw pistons as small as they are no, the centering is done mostly by the piston skirt anyway. If the deal is good buy the saw and don't worry about the ring thing. One benefit to having one ring or thin rings is less friction and normally a little better performance. Really it's not a big deal.
     
  11. JimmyT

    JimmyT AboristSite Guru

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    I would rather have a German made mahle piston with one ring than a Chinese made piston with 2 rings. It all gets down to the the manufacturers machining precision and close tolerances.
     
  12. MCW

    MCW Somebody's talking crap here & it ain't the tree!

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    Looking at it without any real practical experience or proper information many would assume that two rings will seal better than one. As mentioned some of the better saw compressions off the factory floor are coming from single ring pistons and the same saws have proven to be very reliable.
    I even had a guy (car experienced) ask me whether chainsaws have an oil control ring. When I told him about why they don't he went red and was very apologetic :D
     
  13. RandyMac

    RandyMac Stiff Member

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    Get a grip, you need three rings and a domed piston.

    [​IMG]
     
  14. gmax

    gmax Addicted to ArboristSite

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