your safe as long as its not for more than 2 or 3 days,it has to get down below freezing longer than that to do real damage.

Guys, hate be the bearer of bad news , but the maximum expansion of freezing water is right at 32 (within a fraction) when the ice crystals first form.

How long, how cold and will it freeze is simply a function of the temperature that the water in the block actually reaches. Wind is a major factor.

We used to keep a couple of coke bottles filled with water around the marina in the fall, we always had the guys that would call during that first cold snap, usually about 6 on a Friday nihgt and beg us to winterize their boat.

That is a lot of money to gamble with, The light bulb is a good idea, but be careful where you put it. A fire would be worse.

You'll be ok just go out every hour and run the engines up to temp the neighbors won't mind


I just realized you wrote this yesterday...So do you have one solid engine block or two halves

I think the "rule or thumb" is 24 degrees for 24 hours before it will crack a block.

However, I agree with everyone here... Pull your blue freeze plugs (if you have a Merc), and drain the exhaust manifolds.

Good luck!

another thing that can be done if close to water is start the motor and ru to temp
The heat in the block will keep for alot longer then you think

[QUOTE=Mbam]Guys, hate be the bearer of bad news , but the maximum expansion of freezing water is right at 32 (within a fraction) when the ice crystals first form.

Not too sure about this. Might be the maximum expansion, but lacks the hardness to do damage. Do a test in a closed plastic jug and you may see a different outcome. There is a big difference between when the crystals start to form, and when it really gets hard and cracks open the jug. Also, have you ever put the pink stuff in the freezer over nite. If not, try it. That stuff does not remain liquid in your block all winter. It crystalized around 10 degrees or so. Just never turns hard as a rock, therefore there is not enough force to crack steel.

2 nites in the teens around here, the gloves are off and it sucks

Does anyone know the scientific reason why water expands when it freezes.

Found this;

Water is the only compound I know of that expands when it freezes. There may be some others I don't know about, but certainly it's a very rare property. As far as the reason for water having this unusual property, basically it has to do with the structure of the crystal that forms when the water becomes ice. You could use tinker toys to demonstrate this. When the water is liquid, the water molecules (represented by the wooden disks of the tinker toys) are close together, but can slide past each other and move around freely. When it freezes, bonds form which lock the molecules in place in a regular pattern, that stays nearly fixed (molecules can't move around). You can use the sticks of the tinker toys to represent the bonds, holding the disks in place a fixed distance (the length of the sticks) from each other. Whether the compound expands or contracts when it freezes depends on the spacing and structure of these bonds. In most compounds, the molecules end up closer together in this solid state than in the liquid state. But for water, the bonding is such that the molecules end up farther apart in the ice than in the water. By the way, the fact that water expands when it freezes means that ice is less dense than water. For this reason, it floats on the water (look at an ice cube in a glass of water). This property is very important for fish in the winter, because it means the ice forms on top of a pond and insulates the rest of the pond below, preventing it from freezing all the way through