What causes this wear pattern?

This picture shows how all the lobes look  like on my stock   460.  The lifter rides on one side of the cam then switches to the other side  What causes that?
picture next post

What picture are you referring to.

camwear by farmgate, on Flickr

I am in no means a cam expert but have ask the same question to a old timer that built dirt track engines and he told me it is how the cam was designed. He said is just shows up more on a cam that has a lot of miles on them and that pattern was what makes the lifter spin.

the lifters rotate from one side to the other to make the rotation to keep from wiping the lifter and cam out...if they didn't rotate it would kill the cam and lifters....

X2

The taper that is designed into a flat tappet camshaft lobe, makes the lifters rotate. That's what the engineers want them to do, in order to have proper wear.

Charlie

x2 lobe taper , usually 1-2*s MUST be there for lifters to rotate. On a ford one half go one way and the other half the opposite way this "neutralizes the thrust on the cam and helps dtop thrust plate wear.