Thanks, Joe Fulton --- On Sat, 3/13/10, David Crooks <david.crooks@xxxxxxxxxxxx> wrote: > From: David Crooks <david.crooks@xxxxxxxxxxxx> > Subject: [AMC-list] Freeze plugs/ Casting plugs > To: amc-list@xxxxxxxxxxxx > Date: Saturday, March 13, 2010, 4:29 PM > No matter if die cast, or sand cast, > you still need cooling passages inside > the block, which means the cast mold has to keep the > casting material > out of those area's. So any casting mold is not only > shaped like the > outside of an engine, but also all the internal water > cooling parts as > well. and of course, the internal parts need to be > aligned with the external > shape, so what the "freeze plug" holes really are is the > supports for the > internal structure of the mold (ie the water passages). > > The internal bits of the cast will always be > expendable, you have to > be able to wash them out afterwards. Die casting, > where the outside parts > are heavy steel, allows you to pump the casting material in > under > pressure, instead of letting gravity do the work, but that > doesn't change > the need for a removable internal core of sand, or whatever > material. > > FWIW, an aluminum alloy with 12% silicon is an eutectic > alloy! > One of it's advantages is that it will transition from a > liquid to a sold > almost instantaneously, which helps with > manufacturing. All those > Hyper-eutectic pistons you've been reading about, well that > means > they have more than 12% silicon. > > _______________________________________________ > AMC-list mailing list > AMC-list@xxxxxxxxxxxx > http://list.amc-list.com/listinfo.cgi/amc-list-amc-list.com > _______________________________________________ AMC-list mailing list AMC-list@xxxxxxxxxxxx http://list.amc-list.com/listinfo.cgi/amc-list-amc-list.com