Disco 1 my discovery 1 (1995) 2.0 mpi ticking noise..

[Stanleysteamer]

The oem ones.. don't know about the rest.. have a hard coating applied.. once that gets damaged.. worn etc.. the metal underneath wears in a few miles

Nitriding or summat maybe, but they would all need to be treated or they would all wear out in nothing flat.
usually heat treament, induction heating for instance.
And as mentioned above they have to be run in properly with the special lubricant.

 

[kermit_rr]

Nitriding or summat maybe, but they would all need to be treated or they would all wear out in nothing flat.
usually heat treament, induction heating for instance.
And as mentioned above they have to be run in properly with the special lubricant.

The main reason for the running in is to mate to the lifters

 

[Stanleysteamer]

The main reason for the running in is to mate to the lifters

... which is why it isn't clever to swop the lifters around!!

Camshafts are fascinating things. I had a member of my club who designed his own cam and had it ground to his spec by Kent or Someone. It ran fine. I put a high torque cam in a Pinto engine, it too ran brilliant but ran out of puff at higher revs, which was fine and I could get around that by modifying the distributor if I wanted to. I just didn't think a fast road, (of hotter) cam was a good idea in a 30s roadster look alike.
Ran it in in a Cortina MkIV. It was funny to see the faces on the BMW drivers as I flew past them! (it had more "breathing on" than just the cam, but not a lot.)