Thanks for clarifying Bruce! I'm not that familiar with the induction hardening process. I was told the head was basically passed over a machine that hardened it. I didn't know it could be localized to harden only the area around the seat(s), and just assumed the entire under surface had to be hardened -- sort of like a case hardening process or some other heat hardening process (some of which I am familiar with) that can't be localized. We all know that assuming can get you into trouble sometimes... ------------------------------- Date: Sun, 1 Jun 2008 15:28:45 -0400 From: "Bruce Hevner" <scramblr@xxxxxxxxxxx> Frank wrote: understanding is the slightly tougher castings allowed induction hardening of >the entire lower surface of the head, valve seats, combustion chamber and all. Bruce: Where in the world did you get that?? "Induction Hardening" is a localized area type of treatment typically given to the Exhaust seats as a cheaper way of treating the seats compared to installing replaceable seats. I have done a LOT of headwork in 40 years and never seen a head where the entire lower part of the head is treated. That would make no sense operationally OR financially as the only place you really need it is the Exhaust seat. That would make the ENTIRE lower half of the head hard!! -- Frank Swygert Publisher, "American Motors Cars" Magazine (AMC) For all AMC enthusiasts http://farna.home.att.net/AMC.html (free download available!) _______________________________________________ Amc-list mailing list Amc-list@xxxxxxxxxxxx http://splatter.wps.com/cgi-bin/mailman/listinfo/amc-list