Hardened valve seats - do they really matter?

even if they were adequate to start with, castings move and change shape for years until they "season" or Work Harden. especially when vibrated or heated or machined or all 3 or any combination


small block connecting rods on the other hand.....
the small end is often not in the middle of the casting for the small end... why? center to centre fine, the holes need to be the correct distance apart but variance in either direction perpendicular to that in the small end is just shoddy unless there is some bizzare balancing reason....... Ho Hum.

Dave