Quote:
Originally Posted by LubeMaster77
This question comes about because I saw a product on the market that "freezes" a bolt to loosen it. I thought it was dumb but it did get me thinking - at what temp do you have to get to in order to actually shrink a bolt? I guess the answer is "It depends..."?
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That idea is used in installing dry sleeves in aluminum blocks. They usually heat up the block, and dip the sleeves in liquid nitrogen so that the sleeves literally drop right in. Then once the temperature return back to normal you have a nice press fit. When i was building my dad's 951 motor, this was the method used by the shop who installed the sleeves.
As a side note, that product better freeze it really really fast. If the bolt is fastened to something like aluminum then it won't take long for the material around the bolt to catch up to the bolt's temperature. Also any temperature drop will shrink material, the question becomes more of how fast does it need to drop before the hole it's in catches up? And how much do you need it to shrink? .000001" or .001" or .1" (i don't think that last one is possible with most metals but you get the idea)
EDIT: Let me rephrase that last comment, i don't think it's possible with most metals and normal sized bolts.