Doing the valve clearance today. Pulled the cams out, and I'm not nuts about how the tips of the cam lobes look . few pits. what do you think? Hard to see but it looks like a fine line on the right lobe in both pictures. Hard to tell in the pic between the line and some of the reflections.
Dan

intake


exhaust

 

Those look shot.

Good excuse for some new Web cams.

Honestly, don't know what to tell you either way.

 

^^ This.

OR you could buy the webcams and i will trade you for my set of pristine stock cams

 

ok, I am blind, I see a lot of reflections.

 

I honestly don't know what is good or bad. The intake looks like it might have some actual pitting. The exhaust almost looks like machine marking? I was wondering if it is possible to gently clean that intake lobe up with some emery cloth?? Or would that be a big no no?

 

Yeah it's hard to capture with the camera. I circled it (with a square ) for you. The intake is the "worst" , I can kind of feel the pits with my fingernail.



Exhaust not so much of a pitting issue, but a faint line across the very high point of the cam.



I noticed some of this pitting a couple years ago when i had it all apart for the 351 install. At that time i cleaned one of the lobes up with a honing stone. I'm curious what everyone thinks, but I will probably put everything back in the engine and just keep an eye on it.

 

What does the other side look like, the lifter? You've got to figure that the machine that creates these lobes would have a very hard time making that tip without some sort of a mark where it goes from a rise to a fall. If that mark is eating into the lifter then what's the problem? If there is a method, a very fine stone, that you can use to polish the mark out without creating a high spot which would gouge the lifter, then I would do it. Not unlike polishing an intake runner in that you are making a mass produced engine more refined.

 

The lifter , bucket, tappet. (all the same thing?) The things the cams push down on all look fine, I think. I will have to put up a pic of those. They all look and feel very smooth, no abnormalities. The defects in the cam lobe are recessed and do not stick up at all. The majority of the cam lobe is all on the same plane and seems like plenty of surface area to push the bucket down without scratching it.
Dan

 

How do you remove pits with a hone effectively? A hone is maybe good for high spots like when i repair hydraulic rods, but sounds difficult to use for pitting. Cams are case/flame hardened as well... something to think about before you start polishing I think. In machine design when we design our gears; the pitting resistance is by far always the highest stress we are concerned with when we design a gear and select our material/hardening procedure, when we pull gears apart for inspection and we see pitting its usually considered trash... not sure if this applies much to cams I mean it really doesn't look that bad, but maybe lol ;-)

 

Probably just a defect in the actual stock used. I am sure there is a certain percentage of bikes with the same issue.

I wouldn't even think twice about it. Throw it back together and run it like you stole it.

You said the buckets look fine and the pits were there before, it isn't hurting anything.