When racing pontiacs in the 90s, I ran across this process when coming up against the fast guys. If I remember correctly (which I possibly don't) they did the freezing first, then machining. There was some talk about the molecules lining up somehow as @famous bob mentioned.
what i remember , it doesn`t change the molecules , but does change something in the metal , supposedly discovered by nasa on metal that came back from outer space , tuned out it was stronger than when it left
I figured it might help keep from splitting the block between the cam and mains , when pushing the h.p. limits , which I may be doing.................???
