Pulling the engine for new freeze plugs

Oldmanmopar said
Why does every one call these freeze plugs? They were not put there for freezing. They are actually called expansion plugs. They are used to close the holes in the casted engine block and heads. The holes were there to remove the casting sand and wires. Just a freindly FYI. Could be why you don't see them in any machined aluminum blocks or heads.
Cometic gaskets have a tendency to seep at the center rivet on each side. Mr. gaskets tri-metals do not.

People call them freeze plugs do to there origins. If you look in a old tractor or car manual for the 30's or 40's that is what they call them. I even saw an explanation in a manual (I think it was a Farmall) that stated if the block starts to freeze they are soupiest to pop out and help prevent damage to the block. Well we all know that it usually dose not work that way. The block still cracks. But you are absolutely right they are there so they can clean out the block of sand and such.