Cogsy
Well-Known Member
No the cams are not harden. Do you think it needs to be?
I was always told that automotive cams were 'hard faced'. yet a couple of years ago, when I was building a performance motor for my speedway car, I bought a high dollar brand name cam. The instructions from the manufacturer were very clear that the engine must start straight away on the first start with the new cam, and rpm should be maintained above 3000 for the first 10 minutes.
The explanation given was that the cam needed to work harden on the cam follower contact area and slower RPM would cause shearing and smearing of the cam lobe. It then went on to say the cam followers must be kept in order when the engine was disassembled for any reason, as they would become 'matched' to the cam.
I don't know if the cam had any hardening as supplied, but it obviously becomes harder with operation.