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[db252]

Taking apart the 110 and getting parts from Steve at GMR for a 113.  Found this on the rear exhaust valve and the lifter that rides it.  All other cam lobes are good as are the other lifters.  10,000 miles on the motor now.......what causes this?










And now we wait.....

[sadunbar]

Taking apart the 110 and getting parts from Steve at GMR for a 113.  Found this on the rear exhaust valve and the lifter that rides it.  All other cam lobes are good as are the other lifters.  10,000 miles on the motor now.......what causes this?










And now we wait.....

Most likely the bearings are deteriorating in that particular lifter...

[Twolanerider]

Two thoughts that immediately come to mind are: 1) That any appreciable wear should be apparent at only 10k miles is really unacceptable and 2) I've seen others with low miles that looked worse. 

[HILLSIDECYCLE.COM]

Is there actually "measureable wear" on those cam lobes, or rather where the bright cam grinder finish, has simply been dulled?
Scott

[Ridgerunr]

How is the roller on that particular lifter? Any tight spots? causing it to "skate" on the cam. Doesn't look all that bad.....yet. Have seen the "frosting" of rollers with as little as 5000 miles.

[bakon]

I remember cams in TC a few years ago accused of losing "the hardening" looking the same. Not sure about your case or what else it caused.

[HILLSIDECYCLE.COM]

Even a case-hardened part has a depth of approx. .100", or .025" shy of 1/8".
Scott

[HD Street Performance]

I assume this build includes head work.
You may find a stuck exhaust valve to be the root cause or a roller hardening issue. This happens, not uncommon at all.

[db252]

Is there actually "measureable wear" on those cam lobes, or rather where the bright cam grinder finish, has simply been dulled?
Scott

If there is any measurable wear, it's not showing up on my calipers and I also can't 'feel' anything odd. I'm sure it would require a much more professional type of measuring device.  Everything else looks great on them.

[db252]

How is the roller on that particular lifter? Any tight spots? causing it to "skate" on the cam. Doesn't look all that bad.....yet. Have seen the "frosting" of rollers with as little as 5000 miles.

The roller just looks as it is. It doesn't wander, bind or look/do anything different than the other three. Didn't give any signs of noise at all since brand new and the only reason I took it apart was to do the build because I can't leave crap alone. Maybe it's normal.....I don't know. I will take them by to an HD mechanic I know who knows his stuff.

[db252]

I assume this build includes head work.
You may find a stuck exhaust valve to be the root cause or a roller hardening issue. This happens, not uncommon at all.

It does. New intake valves, springs, all new valve guides and all the other magic he does. I've emailed Steve and I'm sure he will give it his do-regard once he gets the heads. Again, no decernable noise ever before tearing it down.

[HILLSIDECYCLE.COM]

AMS?

[db252]

AMS?

I don't know. Steve or whom ever he uses.

[GMR-PERFORMANCE]

Not seeing wear on that cam that is out side of the normal.. Some are worse than others . Reduction of valve spring will help that. As well when we install the new guides we may see an issue that was creating some of this.   

Here is a set that had very low miles on them and as you can see there is roller wear and metal transfer.

[db252]

Whoa........I'll let you guys hash that out.

Anyways, Steve I'm looking forward to the results of your work and getting it back together.