Camshaft Lobe Polishing
 

Is it possible to polish out scoring on a cam shaft lobe?

While doing a valve adjustment, I noticed a little bit of scoring on a couple of lobes. I removed the oil squirter tube and rinsed it thoroughly with a chemical solvent. The solvent squirts out of all the little holes, so if there was an obstruction, it's now gone. The rocker pads all look fine.

Would it hurt to go over the lobes with a fine 600 grit emery board, then finish with a polishing wheel? Would the hardening on the lobe be lost? Would it make a difference? Is it better to have scratched through hardened steel, or smoothly polished steel? I don't think timing would be affected.

I doubt if you can do much good. on the other hand its not likely to cause trouble immediately. I'd look around for a good used cam and put it in when its convenient.

Well, I polished down the rough spots a bit. I'll check it again at the next valve adjustment and see what condition it's in. http://i1376.photobucket.com/albums/...pso70dqpio.jpg
http://i1376.photobucket.com/albums/...psqsrfodwj.jpg

It can't hurt.

Usually there is a depth of hardness, I'd say about 0.030. It really depends on what they spec. Could be 0.015 to 0.09. It looks like you just took out a burnish mark. I think you'll be OK.

I have done some of this on old Cit crank journals. Consider using multiple grades of grit down to the 3000 level. You might surprise yourself at the results.

Check the hardened surfaces of the cam followers. When the surface hardness wears through it creates somewhat of a cutting edge sometimes.

The carbide facing all looks to be in fine shape on both sides. A couple of the top adjustment nuts were unevenly polished/matte, though. http://i1376.photobucket.com/albums/...pshbcathu8.jpg