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Weird cam journal pattern

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Old Jun 24, 2018 | 11:05 PM
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Default Weird cam journal pattern

85k LQ4, pulled the cam to swap & saw this funky wear pattern on all of the cam journals. You can not feel it by hand, the front cam bearing is just starting to show copper. Rod & main bearings look very good. Any idea's what caused this, since the pattern is the same I'm actually thinking the grinder that finished the journals had a bad bearing.

Any better ideas?

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Old Jun 25, 2018 | 07:18 PM
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Could the springs be too week allowing the lifters to bounce?
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Old Jun 25, 2018 | 07:34 PM
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Originally Posted by cookseyb
Could the springs be too week allowing the lifters to bounce?
That's the bearing journals not the cam lobes.
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Old Jun 25, 2018 | 07:38 PM
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Originally Posted by 31coupe
85k LQ4, pulled the cam to swap & saw this funky wear pattern on all of the cam journals. You can not feel it by hand, the front cam bearing is just starting to show copper. Rod & main bearings look very good. Any idea's what caused this, since the pattern is the same I'm actually thinking the grinder that finished the journals had a bad bearing.

Any better ideas?
I agree with you, it was probably like that when installed.
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Old Jun 25, 2018 | 08:18 PM
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Are all of them like that?
Count the number of the marks, would not be surprised if its the same as the number of times the valves cycle per revolution of the cam.
Check your cam chain slack and make sure the cam bearing clearances are right.... That looks like galling from harmonics to me..
Funny thing is its the same type of wear comp cams used to warn about on the cam lobes,, when the cam wasn't broke in with a break-in oil..
But that makes no sense on the bearings, they are not steel on steel..

Weird symptom of the week...
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