What does it take for a motor/block to freeze and crack

[GRADS2009]

We are expected to have some freezing temperatures tonight and I was just wondering how long below freezing or how cold it takes to freeze and crack a block?

 

[ddevore]

I would imagine pretty cold - my parents in flagstaff have seen -9 and never had a problem.

 

[Zaairman]

Several hours of below freezing temps.

 

[boatnam2]

Not sure but i know i had the happen to me.I'm from so cal bought my first house in hesperia so knew nothing about winterizing. The second year they happened to have a real cold winter and it destroyed my motor didn't even know it until close to spring. I had started the boat at home and went to lift the hatch and water was spaying everywhere. Cracked the block in half on both sides, also both manifolds split in half. The place i bought the boat from along the 15 had a pile of cracked motors from other suckers from down the hill. Good thing was dealer told me to put a new short block in it trade it in and get a new boat which i did.

 

[lebel409]

I've stayed a week in Colorado, freezing, snowing, etc. I asked the local about whether I should worry about my motor freezing...they started laughing at me. Hard starts and stumbling a bit, but no issues with freezing.

Anti freeze apparently works.

Boats without a sealed system are a different deal, water pooled, freeze, split, done.

 

[Rvrluvr]

I understand the block will be ok with a closed system, but you still take in lake water to act as the radiator. Would any of the parts that hold the lake water crack/freeze?

 

[Rexone]

A few hours of sub-freeze will do it without antifreeze, especially outside unprotected.

 

[WTRR]

I winterized mine last weekend. I don't know for sure, but if it's outside a building and the temps get into the 20's and stay there for more than 8 hours, you could have a mess on your hands. Another thing to consider is the lower unit if you have an outboard or stern drive. Any water in the oil in the lower unit will freeze and crack the foot. I've seen that a lot more than cracked blocks.
As for a closed cooling system, there is fresh water in the heat exchanger. That will freeze and screw up the heat exchanger. Mine had a flat brass cap over the end of the heat exchanger. I always removed that cap and let the water drain out. Any water that did not drain out had room to expand with the cap off.

HTH...

 

[randyjet]

I had a Jeep CJ 5 and we were doing stupid thing in the night ended up putting hole in radiator and to get home 150 mile we just stoped and added water every 40 -50 miles anyway it got down in the minus 20-30 range that night and my entire block froze never cracked anything but it pushed all the freeze plugs out and it looked like ice bomb pops where every hole was with a cylinder of ice sticking 2 inches out into air. It took 2 days in a garage for the thing to thaw reinstalled freeze plugs and new radiator and drove away. I think they call them freeze plugs because they are the first thing to fail when it freezes (I know they are for casting).

 

[Old Texan]

I just pull the drain plugs in the block and manifolds here in TX and when I lived in GA. So far no problems. Also drop the drive so there is minimal water left.

It doesn't take much more than several degrees below freezing for 6-8 hours to crack a block or manifold. Worst thing to do is have the motor warm from running and then shut it down and leave the water in it with a freezing temp coming on that night. It will freeze far faster in this condition so avoid getting into this situation and drain the water.

 

[Zaairman]

Yeah, you *might* get lucky and pop out a freeze plug, but why chance it??

 

[farmo83]

When I was a kid my uncle's boat cracked during a bad winter storm. Don't know how long it lasted. I know now he puts a 100W light bulb in the hatch and hasn't had a problem. Provided he doesn't lose power I guess. Didn't work out to bad for him as he went from the stock 320hp 454 to a 450 horse LS6.

 

[Old Texan]

When I was a kid my uncle's boat cracked during a bad winter storm. Don't know how long it lasted. I know now he puts a 100W light bulb in the hatch and hasn't had a problem. Provided he doesn't lose power I guess. Didn't work out to bad for him as he went from the stock 320hp 454 to a 450 horse LS6.

You'd be surprised at how much heat the light bulb gives off......You'd alos be surprised at how many fires start from a lightbulb under the hood of a car. Be careful......

 

[farmo83]

I understand in a block water is in a confined space but couldnt the water in an exhuast manifold expand up or out?

 

[Zaairman]

I understand in a block water is in a confined space but couldnt the water in an exhuast manifold expand up or out?

You can crack your exhaust manifolds.

 

[Old Texan]

I understand in a block water is in a confined space but couldnt the water in an exhuast manifold expand up or out?

Manifolds crack more often than blocks form what I've seen. Blocks often saved by the freeze plugs.