cam lobes - Geez Louise

[KA1J]

This time I did it to myself... When I was checking the valve shims a couple months ago I turned over the engine while several of the shims were out. I didn't think of it at the time but now I'm putting the engine back together and see that by my doing that, the lobe hit the metal the well is in. I hadn't thought that possible and that it wouldn't have done anything.

But... there are chips taken out of both sides of the lobes. Nothing that extends outward past the lobes that would dig into the shim and none of them extend much at all onto the lobe but definitely noticeably rounded edges, not a 90 degree angle under high magnification.

Will this cause any problems to the shims if I run it like this?

If so, is there an issue with my putting used cams of the proper years and putting them in instead?

The years that match are

XJ1100J 1982
XS1100G 1980
XS1100H 1981
XS1100LG 1980
XS1100LH 1981
XS1100SG 1980
XS1100SH 1981

Sigh...

[3Phase]

The cam lobe might be okay; might not. You'll have to decide.

It probably won't hurt the shims but if a chipped cam lobe throws chunks and disintegrates while you're riding it will make a mess out of just about everything else in the engine.

You can put in any of the year/model cams you listed but you'll have to check the clearance in the camshaft journals to make sure they're not too tight or too loose for the replacements.

[TADracer]

If you have a few little surface imperfections in the cam lobe you can try to work it out with a 320 grit stone (not sandpaper) and then finish it off with a fine crocus cloth rub. Then check the cam lobe height with a micrometer to make sure its still within tolerance.

[KA1J]

Here's pics of two of the lobes, there are more that have these gouges, none are worse than these but there's still observable gouging on some of the others.

cam1 & cam2 are different aspects of the same lobe. Cam3 & Cam4 are different aspects of a different lobe.





Different lobe...






Are these cams OK to use or are they toast?

[James England]

The cams do transfer heat from the valves, I believe. It looks like you've lost 5% or so of the surface area of the cam lobe. This might affect heat transfer? For all cams cost, personally, I would replace them. I had three sets of cams and could hardly give them away. I sold the last lot for £5

[skids]

There was one member long ago that had his lobes shatter like glass. You might never have that problem, but then again, imperfections like that could be a prelude of failure...like a chip in the windshield of your car.