smokeonthewater
Fleet Admiral
- Joined
- Dec 3, 2009
- Messages
- 9,838
a liquid expanding is not a problem nor is a slush since they would simply overflow... the problem is when water freezes to a solid block and THEN expands.
Air doesnt freeze (at least above -461 degrees, it doesnt). yes, AF will freeze, and it will expand while freezing. depending on the concentration of AF and its dilution with water, anywhere from -86F to +32F
...But I have recently heard that a guy in Nashville said that it is safe to wait to winterize your motor until you see temps in the teens for a couple days (as long as the cold temps last only a few days and it warns up to above freezing during the day time)...
I cannot count the number of times I've read "air doesn't freeze" and I accept the premise. ... It is with that in mind that I question the wisdom of just leaving internal engine cooling channels exposed to salt air. It seems to me that most of the "air doesn't freeze" advocates live inland, where rust isn't near the problem.
Here is a specific example of what happens inside of an engine block over the course of 4 days.
The block probe was placed down the Oil fill cap and was resting on top of the head and valve rocker arms.
The air temp bottomed out right at the crack of dawn and the Block Bottomed out about 3 hours later at 10:30- 11am
A close look at the Raw data shows that the Block Temp bottomed out within 8 degrees of the air temp and and lagged about 3 hours behind.
Note that the Daytime High temperatures exceeded 50F every day.
If the temperature had gone below 22F, The block would have gone below 30F every night.
The block can easily freeze in just one night if it gets cold enough.
In this example, it is a 4.3L V6 block, inside of a modern well sealed Fiberglass Engine Box, under a 2" Sun Pad, Under a Bow to Stern Cover and parked directly next to the side of the house. This makes it about as well insulated as you could reasonably expect.
Your block may not cool off as quickly, but I wouldn't count on it.
One night below 30 degrees is risky if it wasn't warm and sunny the day before.
I have been told it doesn't expand like ordinary liquids do when it freezes. True? False? I don't know. I would like to know though.