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Rocker Arm Shaft Question

How much wear is considered acceptable for the rocker arm shafts? I was disassembling my heads last night and was surprised at the amount of scoring that I noticed on my shafts. Is this considered "normal" wear? Thanks in advance.
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Mark
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Old 02-15-2007, 05:40 PM
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I am thinking anymore then a shadow would be too much
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Old 02-15-2007, 08:52 PM
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You can measure the outer diameter with a caliper. I recall mine were 18.02 mm, surprisingly all of them were. There are tolerances mentioned in Wayne's book.
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Old 02-15-2007, 11:13 PM
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I would be concerned for reason for the "wear"
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Old 02-16-2007, 04:42 AM
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I consider more than .0003" unacceptable.
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Old 02-16-2007, 02:05 PM
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Wow, 3 10thousandths! My micrometer isn't that good, but no wonder they were all 18.02. Thanks camgrinder.
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Old 02-16-2007, 02:12 PM
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Well, I don't have a spec book for an '87. You should absolutely have one, or the factory workshop manual, to guide you through all mechanical work.

My old book for the '65-68 cars says the specs are:

Rocker arm shaft: 17.992-18.000 mm

So the difference is 0.008mm, or 0.00031496063" (which is exactly what Camgrinder said, 'cept in "English." )

The rocker shaft bore in the cam housing is listed as 18.000-18.018.
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Old 02-17-2007, 11:58 AM
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Some scoring seems to be common on the shafts. That doesn't mean they are worn out. You can check with a micrometer. I install them with the scored surface on the "outside" so the smooth surface wears for the second life of the engine. Worn out rocker arm shafts and bushings will be noisy. Not dangerous but annoying.

-Andy
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Old 02-17-2007, 04:27 PM
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Thanks for the input. I'll "mic" them tomorrow and see where I am at.
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Old 02-17-2007, 06:14 PM
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Anything wrong with Eagledriver's process? Aren't these under pressure from the "bottom" only?
Thanks
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Old 04-07-2008, 12:33 PM
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Old 04-07-2008, 12:33 PM
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