Interesting opinion!!

Lets look at it logically and I am well prepared to stand corrected on this......

2 components that contact each other must have similar level of hardness otherwise one will wear considerably quicker than the other, right?

However, their respective hardness must represent the level of wear that you wish to achieve. Brake discs and pads is probably a fairly good example. Its important to get the right balance of a pad thats hard enough so as to achieve good friction and wear properties, but so that its not so hard that it wears the disc out prematurely.

Taking that logic, I would expect that with the Cam/Followers scenario that the cam must be harder than the lifters, so that the lifters become the replacement part in the same way that a brake pad is.

In the real world, using this logic, I would perhaps expect to see that a Cam would, for arguments sake, have a hardness reading of 60 and that the lifters would read slightly less, perhaps 58 to allow them to wear quicker than the cam.

Am I making sense so far?

I now of a Kent Cam that was independently tested recently and the results were :-

Cam - 40 Rockwell
Lifters - 60 Rockwell

This seems to match up to the fact that 4 out of 4 Kent Cams that we have removed recently have been worn beyond belief and all at a VERY early stage of their life. Only one of these was fitted by us and we certainly followed the correct running in procedure. The other 3 were fitted by 3 different people to 3 different cars. One had done less that 100 miles.

I know that this has taken the post a little off the beaten track, but I feel that its relevant and its about time that some other opinions were gathered as there is no doubt that if what I say is actually true, then there are alot of people with alot of worn metal material floating around in there engines.

I emphasise that this was only 1 cam tested and the test was nothing to do with us, I just happened to find out the results of it. I would be interested in finding out if anyone else has any thoughts on this. Please educate me if I am miles out!!