technical issue don't know where to start.

[Old Guy]

i went to the machine shop yesterday and took the camshaft and the cap and they said it wasn't bad and I could work it out with some emery cloth so that is what I will try first they said they don't know anyone that could line bore that and that they have a tone of heads in there shop with the same issue but worse that are just scrap now. I will update you and send some pics as I go. I took the rockers out so I could test fit the cam back in and turn it as I work it. also if it works I was going to throw some lma's at it from sos.

I can understand the machine shops reluctance. It is not a low risk repair.

From the photos, its hard to tell exactly how much and what the damage is to the journal. If that is just material deposited on the journal, then the machine shops strategy might work. The big problem is making sure that you don't open up the clearance on the journal when you clean it up. I would start with a grit that is well over 1000. If there is material removed from the journal (scratches), I don't see the machine shops strategy working, Removing the scratches will open up the bearing clearance. You might be able to polish off surface debris, leaving the scratches and then check the bearing clearance using a plasti gauge. If the clearance is OK you might be able to get away with it. However, I think you are kind of in un chartered territory here!

Perhaps give someone like SOS a call and see if they have ever done a restoration on a journal like this or what their repair solution would be. If they say that they can fix it, you might want to send it to them before you do something that makes a repair impossible. If SOS says they have no solution, then you have nothing to lose other than your time and the cost of parts used up in reassembly.

 

[charlee]

well i pulled the cams while i was doing the timing belt to do the sos lma's and found on of the journals the intake cam rides on was chewed up a lil bit and caused it to bind. question is now what do i do?
View attachment 125389View attachment 125390

How did this happen? Is this common in cars in general or NSX specific?

 

[kboose07]

well just read this I prolly should have gave sos a call but I ended up polishing the build up off and leaving some of the scratches in the journal because I was told not to worry about them because they would just fill with oil. I put it all back together Saturday and fired it up then drove it for about four hours no issues. I do want to set the valve lash on the exhaust side but I had a hard time getting to them any tips? biggest issue was not being able to see them I had a small mirror and yea right.I'm amazed after all the work done to the car it fired right up without any hesitation what a car! I'll post some picks up later of the work done and the journal so you can see thanks for the help I appreciate all the advice.
I found a few other people with wiped out cam journals and from what I can tell is that the cars are not driven dose not help keep things lubed up and oil starvation in tight right corners can cause this, and the machine shop told me a lil bit of dirt is most likely the cause of mine they said that it gets in between the cam and the journal and goes around and the aluminum raps around it.