Cam journal scoring.

[ClarkGriswald]

Hi all, Just had a question about the cam/head interface. Maybe some of ya remember that when I was adjusting my valves recently (and discovering all the PO stuff) that I had found the #s 1 and 2 bearing caps on my intake cam were swapped. 1 was were 2 was supposed to be and they were reversed so that the arrows pointed left.. Well now that I have the head off I found that the #2 bearing cap and its partner on the head, as well as the journal on the cam are pretty scored up. The oil hole on the cam journal is nearly shut because of the scoring.

Im assuming that whatever particles/chaff came or will come out of that mess will travel around and not be a good thing. I believe that it is this as well as the funky oil ring dragging thru the #1 bore forever are what made all the little bits that I orig found in my oil along with the chunk of #1's second compression ring.

So what are the options? Nothing? Doesnt look like anything can be done with no bearings in there. I guess Ill get another head from the man if thats the story. I cant see putting it back together and just calling it good knowing that its eventually going to continue self destructing and contaminating my oil.



Theres a few more journals/caps on both caps that are maybe 60 percent as bad as that one.

[TADracer]

It would be my guess that any chaff that got loose will be a very small amount of aluminum from the caps and the head so that will probably not upset anything too much in the rest of the motor. The oil filter probably caught most of it already. I think the caps and head will probably be way out of tolerance once the bearing surface is cleaned and polished up. The head and cap may be able to be fixed by some wizard who works with aluminum but is probably not worth the cost involved. The cam is steel, granted not hardened steel, but the journals may be able to be cleaned up a bit and checked with a micrometer. Since the aluminum is softer than the cam perhaps alot of the scoring on the cam is aluminum deposits that can be easily removed.

If you have other caps that are in this condition and were in the correct positions then perhaps you should check on the oiling up to, and inside the head. Poor oil flow could have been a large contributor to the problem. Also, check the oil passages in the cams.

I would check the cams and reuse if within specification and invest in another head with the matching caps. Take the opportunity to do a nice valve job, clean up the chambers, replace the stem seals and take care of the valve springs and shim the valve lash if necessary while in there.

[TADracer]

BTW, I am sure you know you have to fix the rings too if they are not up to par. Sounds like this is all a good time to do it.

[prometheus578]

Can't think of anything else to add that TADracer hasn't already said.

[bikerphil]

cyl. head

Good time to throw a 78-9 head on there for a little XStra HP. More compression!? JAT.