View Full Version : How cold, how long to freeze engine block

06-07-2009, 10:17 AM

Any idea how cold overnight lows have to be to freeze the engine block? I would imagine it would have to get down to atleast the high twenties and stay there a few hours? Talking the potential of snow here the next night or two. The boat is on a lift at the lake which is about 35 minutes out of town. May have to pull her out and garage her this week. And to think I skiied on Wednesday evening 79F, water 53F and no wetsuit!

06-07-2009, 12:37 PM
Technically think of your freezer.

As soon as the weather drops below 32 degrees water will have already began to freeze. mostly likely there is air in the block water channels because this is not a pressurized system

I would get the boat home and get a space heater, open the side engine covers to the ballast area, put the space heater in there and that way its sure to keep the boat warm.

06-07-2009, 01:16 PM
I just put a light by the engine and a few blankets over the doghouse during really cold nights, but the boat is also winterized already. If it is only for a night or two I think it should be fine because the air has to cool down alot of material before it gets to the water. But hey, with summer around the corner a cracked block would be the last thing any of us want, so do what you have to do.

06-07-2009, 01:34 PM
I agree with insanepolak it would have to freeze fairly hard and for at least 24 hours. A light in the engine compartment would be fine. I used to prop open my doghouse and let a space heater run on low on the really cold nights only because I had a shower and a heater and I didn't think the light bulb would help keep them from freezing. Leave the cover on and make sure it has one of those tip over power safety thingies!

06-07-2009, 01:58 PM
Check these out, Magnetic Engine Block Heaters (http://www.tractorpartsinc.com/magnetic_block_heaters_269_ctg.htm). How easy can it get? :D

06-07-2009, 06:21 PM
If you have a heater it will freeze before the block does. I think my service department said it will take about a night of a freeze for the heater to crack and about 24 hours for the block.

If it was me i would take it home and blow out all the lines then put a blanket over her with a light on or the cool engine heater like this one. http://www.boatownersworld.com/bilge_heaters.htm

That is just me but do some simple stuff might save you alot of time and pain oo ya and money down the road.

06-07-2009, 10:08 PM

#1 go to lake / boat.
#2 drain engine and hoses and water pumps etc..
#3 relax and drink a beer.
#4 piece of mind and can sleep at night knowing boat engine will not freeze.

Been there done that. 80 deg one day and 6" snow the next . This happened 2 boats ago here in Colorado and I had to do the same thing. See you this summer.
Jim .

06-08-2009, 03:22 PM
Thanks for all the advice guys. I went out yesterday and all was fine. The place were they take the the weather data is about 10-12 miles from the lake. The lake is it's own little micro climate and stays a few to several degrees warmer overnight (or so my neighbor out there says).

But for future reference can anyone post pictures of where the block plugs are located for a direct drive? What size fittings to remove?

Sounds good Jim, see you in the summer.


06-08-2009, 03:36 PM
Hey Kurt glad to hear the boat will stay warm enough.

Check this thread out bro.


06-08-2009, 10:07 PM
Normally air over a lake is slightly warmer. if you have fruit trees you can actually fill buckets of water in place under your fruit tree and the blooms will not die in a light frost.

Freezing also has a lot to do with pressure. Water freezes at 32 F under standard pressure. Anything over or under standard pressure causes changes. In pressure, I mean barometric.

ian ashton
06-09-2009, 03:01 PM
I wouldn't be too worried about freezing. Worst case I'd say just lower the boat into the water, especially if its only supposed to be cold over night. Our boat was in the water a few times this spring while it was snowing and we had no issues at all.