My comment/question is about the difference between heat treatment and heat cycling. In the context of this discussion, I believe there is a difference. Heat treatment is a process of material hardening that occurs at the time of manufacture (quenching being a popular method). But heat cycling is a process of stress-relief. A piston has a lot of internal stress created by the forging process. The metal is literally beaten into shape and this has profound effects on the grain structure of the metal. Internal stress is created and cycles of heating and cooling releive that stress. I don't believe that the heat treatment that occurs during manufacture addresses stress-relief.

It should be noted that this only matters with forged pistons. Cast pistons (such as most stock pistons) do not require stress-relief (by nature of their uniform grain structure) and therefore don't require any heat cycles. Forged vs. cast pisons make a difference in how an engine should be broken in.

I'll save my thoughts on ring seating for another time...

Comments?