Fw: "freeze plugs", "expansion plugs"

["Bob Merritt Simplex Mfg" <bob@xxxx>]

RRRrrreceived this from the Michigan Mob:


With the regard to "expansion plugs" and "freeze plugs", there is no word
description in any parts book from 1951 thru 1965 that uses this
terminology. All references to these "plugs" are listed as "plugs, core
hole".
These "holes" are cast into the blocks and heads to remove the sand cores
that remain in the block and heads after the cast iron is introduced into
the engine mold. The only way to remove the sand cores inside the castings
is thru these "core holes". The inner mold is to create the water passages
inside the casting. Then when all sand material is removed, the "core holes"
are machined to accept a "plug". There are two types of "plugs", early are
dish type, later are cup type. Both are installed with a special tool at the
factory for each type.
"Expansion" and "freeze" plugs is terminology used by by the layman
mechanic, which really is more understandable by everyone.

George Riehl