Beware of 4-08 Clevite V rod bearings

Discussion in 'PSI Superchargers Tech Questions' started by Will Hanna, Jul 20, 2009.

  1. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    Just got word of a racer who had 5 bearings out of the 4-08 batch of Clevite V rod bearings have severe delamination issues on a 200 foot pass. Reportedly, the back of the bearing looked brand new, so it apparently wasn't from excessive chatter.

    Just figured I'd pass it on to everyone to check your bearing batch numbers.
     
    #1
    Will Hanna, Jul 20, 2009
  2. blownapex

    blownapex Member

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    bearings

    chatter
    not trying to butt in but the back of my v bearings are
    transfering aluminum from the grp rods
    they are black /grey like polishing aluminum
    bearings measure good after 8 runs then they get
    changed
    brad 5 4.250x4.467 superman @38lbs 27 deg timing 1/8 mile only
    2700lb pro mod 4.10-4.15 1/8 mile
    any ideas
    thanks
    duane
     
    #2
    blownapex, Jul 22, 2009
  3. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    chatter

    it's not unusual to see this after 8 runs on a bearing, unless it's excessive.

    are you measuring the 'spread' across the top of the bearing? this is a commonly missed measurement. it should not be below 2.500. if it is, you can gently bend the bearing out, applying pressure at the base with the thumbs and then pushing outward, but if the bearing is less than 2.495 or so, it either has too many runs on it or it's a sign of detonation. If it's 2.48 or less, then it's got way too many runs on it or it's getting hammered. I've seen them hammer the bottom out one run then not on the next, but the spread generally shows this every time.

    Hope this helps.
     
    #3
    Will Hanna, Jul 23, 2009
  4. alkyholic

    alkyholic Jr. Dragster

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    I just went though my bearings and on #6,7,8 the surface is all bubbled. I've never seen this before but i'm assuming thats delamination. They measure out fine and nothing was transfered to the crank. The tune up was very safe. 400ft pass.

    04/08 v bearing

    Is this the same issue?
     
    #4
    alkyholic, Jul 24, 2009
  5. Blownalky

    Blownalky Top Sportsman

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    I know it's not delamination, but putting my engine together now an ran into a set of rod bearings, dated 10/08 that seem to have the dowel hole drilled offset. When you put the lower shell in the cap, it's shifted so the tang side is sitting up about .025. Anyone seen that before?

    Just grabbed another set and they fit right in normally.
     
    #5
    Blownalky, Jul 25, 2009
  6. alkyholic

    alkyholic Jr. Dragster

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    I just confirmed that this was the same issue as the racer in the first post. It is indeed delamination. Run these at your own risk.
     
    #6
    alkyholic, Jul 27, 2009

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