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  1. #1

    riva .020 piston specs

    hey guys just turning to your advice again i bought some riva .020" for a stock boost set up ...the cylinders had been previously bored i'm just bouncing some things off you guys ...the riva end gaps are a little tighter then stock on the top right and looser then stock on the 2nd ring... top ring is .016-.018" (compared to .012-.020" stock) ....and .020-.022" (compared to .006-.012" stock ).....the stock wear limit is .06"

    what i'm getting with feeler gauges is a loose 18 thou top 19 will not fit and 18 thou 2ND ring and it doent seam to matter if i move the rings to another bore in the block

    what are your previous experiences ?

    also the riva installation sheet says the top ring is silver....and the 2ND ring is dark gray
    both rings are a dark gray with the exception of the ring to cylinder wall matting surface on one is a steel gray/silver colour ..... i have had the block along with the pistons at a machine to deglaze the block and hone the block to match the pistons and everything is within spec but the end gaps seem to be backwards according to the colour identification....any input would be helpful

    thanks JUSTIN


  2. #2
    Nothin' better than Doo'in it! BigDaddyRXP's Avatar
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    You just need to worry about riva's piston ring specs... not the stock ring specs! Riva's rings are generally a file fit ring. Fit them to there specs, or larger depending on the amount of boost you plan to run. The colors your speaking of are the sealing surface of the rings, also if you notice.... the thickness of the rings are different. The bottom ring will not fit into the top slot on the piston.

  3. #3
    ohh.......ok yes i did notice the size of the ring ...although i did not try to fit it into the ring land ....thanks for clearing that up for me

  4. #4
    just an update i measured both rings and they are both .046 thou ...so they could be interchanged ....by mistake ....
    would it be safe to leave the 2ND ring .002 tighter then spec seeing as it is still looser then stock ...i'm just nervious about takeing too much off the ring or not fileing it square

    thanks again JUSTIN

  5. #5
    West Texas RXP skoepp's Avatar
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    Most reports that i have seen is that the 2nd ring (middle) gap has been tight on the riva's.
    Mine were .012 to .014" and seen some reports of .008"

    The rings are different thickness and need to be placed according to instructions.
    Use the ring gap range below.
    RING GAPSTOP-TOP.016 ~ .018"2ND.020 ~ .022"

    Top ring (silver)b2nd ring (dark grey)NOTE: Install rings with writing side up towards top of piston.cOil ring rails (2)1Piston trust side axis2Piston pin bore axisNOTE: Do not align ring gap with 1 or 2.

  6. #6
    Nothin' better than Doo'in it! BigDaddyRXP's Avatar
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    Quote Originally Posted by jtrudel90 View Post
    just an update i measured both rings and they are both .046 thou ...so they could be interchanged ....by mistake ....
    would it be safe to leave the 2ND ring .002 tighter then spec seeing as it is still looser then stock ...i'm just nervious about takeing too much off the ring or not fileing it square

    thanks again JUSTIN
    Both of your rings are the same thickness I've got a set of .010" overs, and the lower ring is thicker than the top ring. I don't have any exact numbers at the moment.... but I know it wouldnt fit in the top piston grove

  7. #7
    Mine were ordered from Jerry back in October and they are the 20 thou over and none of the rings have writing on them the dark gray one 2nd ring does have a little divit similar to a punch mark on it though... so I assumed that faced up and it is a little wider then the first ring (silver) I have a set of 3 and they are all the same from one bore to the next and look identical

  8. #8
    I am also squaring up the ring with the piston being slid into the bore

  9. #9
    Quote Originally Posted by skoepp View Post
    Most reports that i have seen is that the 2nd ring (middle) gap has been tight on the riva's.
    Mine were .012 to .014" and seen some reports of .008"

    The rings are different thickness and need to be placed according to instructions.
    Use the ring gap range below.
    RING GAPSTOP-TOP.016 ~ .018"2ND.020 ~ .022"

    Top ring (silver)b2nd ring (dark grey)NOTE: Install rings with writing side up towards top of piston.cOil ring rails (2)1Piston trust side axis2Piston pin bore axisNOTE: Do not align ring gap with 1 or 2.
    Is that how yours came from RIVA and if so what did you set the end gap to on the 2nd ring ....? Or did you leave it like that

  10. #10
    West Texas RXP skoepp's Avatar
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    Quote Originally Posted by jtrudel90 View Post
    Is that how yours came from RIVA and if so what did you set the end gap to on the 2nd ring ....? Or did you leave it like that
    Top rings were .018 just like yours and specs.
    Took 2nd rings to .020"

    If your 2nd rings are .020 to .022 like your stated then you should be good.

    I need to clarify that mine are 1st size over pistons and the others i have heard of the 2nd ring gap being tight were also first size over.
    Its possible that the 2nd size over rivas are good to go.

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