Intakes crack a lot, evidently.

Here is what happens to the block if the freeze plugs aren't enough protection.

Here is a 2-bbl that got ice in it I believe, now THAT is an intake crack.

Here is also a marine engine I dismantled a while back. Bad fire probably followed by water to put out the fire. I noticed the cam bearings were loose and FELL OUT when I removed the cam. Evidently the intake heated, expanded, and broke the block right down the middle.

 

Holy s&@t!

 

 

Ouch!


That'all teach'em. Freeze plugs ain't going to fix that.

 

I'd like to see FLEX SEAL fix that!

 

Everybody calls them "freeze plugs" they are NOT.
The intended purpose of the holes in the side of the block was to support the inner sand cores during casting and to remove the sand after casting.
The proper term for them is "core plugs"
The engineers that designed these engines could have cared less about blocks breaking because someone left water in them during freezing weather. That is what ethlene glycol is for.

 

It was actually an unintended benefit as a freeze would push them out as the water expands, sometimes saving the block.