Freeze plug is a misnomer.

Correct. It's a core plug.

People named it freeze plug / frost plug because they tend to pop out when block freezes.

It's kind of like a Oven Roaster Chicken. When it 'pops' it is usually done.

And they damn sure don't prevent any damage to the block. I get the feeling that some people think they're there as a relief device.

I have seen several people get lucky with replacing the freeze plug. If they actually winterize the boat but some water stays in the side of the block with to much sand (mostly because they power onto the beach with motor running), then it will push out the freeze plug. I am always very skeptical, but even last spring one of guys down the street stopped by and asked why he found this strange plug in the bottom of his bilge. He went to the auto parts store and bought a rubber freeze plug and boated all season with it. Where we boat we have a lot of sandy beaches, so if the isn't your case and winterization wasn't performed, your block is most likely cracked.

that's because its a core plug... not a commonly mistaken "freeze plug" they put these in so they can get the sand out after the block has been cast!!!

i wonder how long it will take for a certian expert to say it popped out because the water was not cooling the metal in the block,lol.

Remember the guy in TX, said they popped out because the sun was to hot...................... ahhhh ok

yes, they keep the freeze in

now now... lets play nice

Post 25 is correct and FWIW Mercruiser calls and lists them as expansion plugs. Just saying, everyone calls them freeze plugs (on the side of block) especially for the marine side of things..