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Valvetrain Nightmare

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Old 03-18-2015, 09:54 PM
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My friend has a 2004 ZO6 with a LS6. He determined a lifter had failed and began to tear down the motor. An inspection of the lifters revealed that 13 of them had severe wear/deep scoring of the rollers. Peeking through the lifter pockets at the cam lobes showed similar damage.

He is going to replace all damaged components, but I am curious about the cause of the scoring so it can be rectified.

The cam was installed before he purchased the ZO6 so I'm wondering if the supporting valvetrain components were adequate to support the new cam?

Any ideas from some valvetrain experts will be be greatly appreciated and taken into consideration in the planning and research for the re-build.
Old 03-18-2015, 11:33 PM
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I am also going to swap my stock cam in my 2011 CTS-V for a custom grind positive displacement blower cam from Brian Tooley.

To support the new cam I am also installing BTR's .660 lift platinum dual spring kit with titanium retainers,locators, and seals, 5/16 LS chromoly pushrods, BTR's LS rocker arm trunion upgrade, an IWIS timing chain, and a LS2 dampner to replace my probably broken LS3/LSA tensioner.

ARH long tube headers, larger crank pulley and FIC 1000 injectors will round out the build.

I'm hoping all bases are covered cuz pulling out lifter after destroyed lifter was pretty horrific and something I would like to avoid.
Old 03-19-2015, 07:48 PM
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Does anybody know why a C5 LS6 has scoring on 80% of lifter rollers with a cam swap being the only change from stock?
Old 03-19-2015, 08:55 PM
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Run low on oil, got dirt or debri on the oil during the cam swap or soon after... I'm sure there are many reasons.
Old 03-21-2015, 09:17 PM
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oil pump O-ring not properly seated....sucking air....aerated oil=bad for all internal engine parts
Old 03-29-2015, 11:05 PM
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Originally Posted by A.R. Shale Targa
oil pump O-ring not properly seated....sucking air....aerated oil=bad for all internal engine parts
Posible however if thats true than you also wont get oil pressure either.
I always disassenble oil pump and make sure it seated right than out back rotor abd oil pump cover torwue the bolts. I use comp red valve train lube on oil o-ring.

Once i asked comp cam why lifters get scoring ...his answer oil related either low or dirty or valve train not stable or even wrong oil.
Since i did supercharge since than i always use rotella 15w40 abd change frequently about 2k.

I have since change heads twice and 3 cams....lifters and cam looked great. Si i will stay with rotella.
Old 03-29-2015, 11:07 PM
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Dang too many typo mistakes...not good on smart phone keyboard.
Old 05-08-2015, 10:32 AM
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check the pushrod length and valvetrain geometry and lifter preload

me thinks somebody stuffed the wrong lenth (too long) push rods in or the cam wasn't properly surface hardened (soft cam)

roller cams don't wipe very often so something is amiss (master of the obvious)

hope this helps!
Old 05-08-2015, 02:17 PM
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with all that worn metal going thru the motor, he could have some serious wear on the bearings too. Just food for thought.

Sorry for the bad luck



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