Beemon Posted February 19, 2018 Share Posted February 19, 2018 Anything I should worry about here? I don't have heated storage and the temps this week ate going to be high teens. I'm running 50/50 antifreeze so I'm not worried there, moreso 60 years of metal shrinking and thermal expansion. Link to comment Share on other sites More sharing options...
NC-car-guy Posted February 19, 2018 Share Posted February 19, 2018 We had an unusual week of teens and twenties here in NC recently and I had no issue 1 Link to comment Share on other sites More sharing options...
Bloo Posted February 19, 2018 Share Posted February 19, 2018 I have never heard of one of these falling out from age or any thermal cycling that did not involve freezing. If you have sufficient antifreeze, its fine. 1 Link to comment Share on other sites More sharing options...
avgwarhawk Posted February 19, 2018 Share Posted February 19, 2018 I have never witnessed a catastrophic failure of a freeze plug. I have seen them start weeping from a rusted spot that has found a path through. Proper antifreeze levels and your good. 1 Link to comment Share on other sites More sharing options...
60FlatTop Posted February 19, 2018 Share Posted February 19, 2018 You have text books that will show you the coefficient of expansion difference between a steel pug and a cast iron block. Put the books to practical use. Get the real benefits of engineering study. I'm not going to say it ain't rocket science, but look up Invar while you are in the table. We used that for stuff in cold places, like -459 F. 50/50 antifreeze is fine. Freezing will push a plug out, the problem is that water expands in all directions when it freezes. The only way the plugs protect against freezing is when you use water smart enough to go to the plug when it gets solid. Just from observing people whom drink it, I think smart water is pretty rare. Bernie 1 Link to comment Share on other sites More sharing options...
Bob Engle Posted February 19, 2018 Share Posted February 19, 2018 It's interesting that the myth of freeze plugs is to prevent damage from freezing. In reality they are core plugs whose purpose was to have an opening for the removal of the sand core used in the initial casting of the part. As mentioned, their only failure is corrosion. Over time , galvanic activity from coolant turbulence and oxidation will take their toll. Regular antifreeze change is the only good deterent. In time even the best of care will not prevent the need for replacement of the core plugs. Bob Engle 3 1 Link to comment Share on other sites More sharing options...
avgwarhawk Posted February 19, 2018 Share Posted February 19, 2018 1 hour ago, 60FlatTop said: You have text books that will show you the coefficient of expansion difference between a steel pug and a cast iron block. Put the books to practical use. Get the real benefits of engineering study. I'm not going to say it ain't rocket science, but look up Invar while you are in the table. We used that for stuff in cold places, like -459 F. 50/50 antifreeze is fine. Freezing will push a plug out, the problem is that water expands in all directions when it freezes. The only way the plugs protect against freezing is when you use water smart enough to go to the plug when it gets solid. Just from observing people whom drink it, I think smart water is pretty rare. Bernie Its readily available now. 3 Link to comment Share on other sites More sharing options...
Beemon Posted February 19, 2018 Author Share Posted February 19, 2018 Thanks guys. Bernie, as with most things talking about old cars with old people and supplementing an engineering degree, I'm often told I'm wrong despite citing from my books. Also these books didn't help me with a legal case so I thought I'd just ask. Link to comment Share on other sites More sharing options...
Guest Posted February 19, 2018 Share Posted February 19, 2018 While working in a GM dealership in the prairies in the 60's I saw two Oldsmobile engines badly cracked in -45 degree weather and the "Core plugs" were totally intact in the block. Link to comment Share on other sites More sharing options...
Guest Posted February 20, 2018 Share Posted February 20, 2018 There is a weaker region, at least in the later nailheads that tends to crack first. It is typically behind the starter motor. I have seen cracks running horizontally starting by the starter and continuing up to the center of the core plug hole and then on the other side onto the next. Good ol' Many-snow-dah, you can see a lot of blocks that folks have tested with a minimum of % of anti-freeze. Its "fugly"! Link to comment Share on other sites More sharing options...
trimacar Posted February 20, 2018 Share Posted February 20, 2018 9 hours ago, Bob Engle said: It's interesting that the myth of freeze plugs is to prevent damage from freezing. In reality they are core plugs whose purpose was to have an opening for the removal of the sand core used in the initial casting of the part. As mentioned, their only failure is corrosion. Over time , galvanic activity from coolant turbulence and oxidation will take their toll. Regular antifreeze change is the only good deterent. In time even the best of care will not prevent the need for replacement of the core plugs. Bob Engle Yes, thanks Bob, that's 100% true, but a LOT of people over the years thought they were for freeze protection...and as Bernie so well states, water just ain't that smart when it comes to freezing....I won a state science fair once, because the judges asked me about materials contracting, getting smaller, when getting cold, and didn't water do that too...but I'd studied and knew that water is unique in that it contracts down to 32 degrees F, and then as it freezes it starts expanding....destructively as we know.. Link to comment Share on other sites More sharing options...
Frank DuVal Posted February 20, 2018 Share Posted February 20, 2018 Yep, another automotive myth. Having a father who worked in a foundry most of his life, I know what cores are in casting parts. Put this in the same file as "polarizing a regulator" and "6 volt cars won't start in the winter". Anti -Freeze keeps water from freezing, and its volume increases when it freezes (a very rare quality!), thereby cracking the container it is in. Core plugs were not designed to relieve this stress. 50/50 ethylene-glycol is better (has a lower freezing point) than 100% ethylene-glycol. Link to comment Share on other sites More sharing options...
RiKi5156B Posted February 25, 2018 Share Posted February 25, 2018 I had a soft plug fall out of a Mercury Y block this past winter.It was a standard Napa cup type. I live in the same general area as Beemon and my shop being unheated was single digit hell for a while. The block was dry nothing in it. Link to comment Share on other sites More sharing options...
old-tank Posted February 25, 2018 Share Posted February 25, 2018 Back when I could not afford antifreeze (or just chose not to buy), i would drain the radiator after driving and then fill the next day. On one 10*F morning I filled with cold water that froze in the radiator after a few miles of pulling air through (chugga, chugga, gush!). The next day while the engine was running with an empty radiator I filled with boiling water (gush, splat, clunk went a block freeze plug). That's when I discovered the miracle of those rubber expanding plugs, since even under ideal conditions it is nearly impossible to replace a block plug on a nailhead. So the plugs will come out in freezing conditions, but you have to work at it!! 1 Link to comment Share on other sites More sharing options...
JohnD1956 Posted February 26, 2018 Share Posted February 26, 2018 How long can those rubber plugs last though? Link to comment Share on other sites More sharing options...
Bloo Posted February 26, 2018 Share Posted February 26, 2018 Not long enough. I am not doubting the guy who had a metal one fall out, but I do think it is extremely rare. I have never seen that or heard of it. I *have* seen the rubber ones fall out...... I don't trust them as far as I can throw them. It might beat pulling the engine though. Link to comment Share on other sites More sharing options...
mackensen Posted February 26, 2018 Share Posted February 26, 2018 how do you eat a temp. Link to comment Share on other sites More sharing options...
old-tank Posted February 26, 2018 Share Posted February 26, 2018 12 hours ago, JohnD1956 said: How long can those rubber plugs last though? In this case 10+ years and ~100K miles. And only in an emergency again...I did not have the proper tools or facility back then. Like I said, you can pop a plug if you work at it; in this case I could have just as easily split the block wide open! 1 Link to comment Share on other sites More sharing options...
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