So how cold, how long, to freeze your I/O?

[H2O]

This is my first year with an I/O (after a lifetime of owning outboards).
Can anyone guess how cold it has to be, and for how long, to freeze the residual water in the engine block enough to do some damage?
It has been 60 here during the day, but just touching 31 to 32 for an hour or two overnight.(I'm hoping the thermal mass of the engine being warmer all day, didn't allow the block to get cold enough to freeze overnight.)
I planned on running some anti-freeze through for winter prep, but I injured myself and required shoulder surgery. I wasn't sweating it too much, because it virtually never goes below freezing here on the coast, but the last couple of nights have touched 31 to 32 overnight.
I going to winterize it as soon as I can, but I'm kind of stressing over the idea that I might have already F'd it up.:(
Thoughts?

[phebus]

Run an extension cord, and place a shop light in your bilge to heat it until you can winterize it. Is the boat stored indoors or out?

[DCBob]

This is my first year with an I/O (after a lifetime of owning outboards).
Can anyone guess how cold it has to be, and for how long, to freeze the residual water in the engine block enough to do some damage?
It has been 60 here during the day, but just touching 31 to 32 for an hour or two overnight.(I'm hoping the thermal mass of the engine being warmer all day, didn't allow the block to get cold enough to freeze overnight.)
I planned on running some anti-freeze through for winter prep, but I injured myself and required shoulder surgery. I wasn't sweating it too much, because it virtually never goes below freezing here on the coast, but the last couple of nights have touched 31 to 32 overnight.
I going to winterize it as soon as I can, but I'm kind of stressing over the idea that I might have already F'd it up.:(
Thoughts?
You're probably ok. It needs to freeze pretty consistantly for a few days in order to freeze up the block water. That said....if the motor dosen't have drain petcocks, install and use them during the winter...or, put a drop type trouble light in the motor compartment turn it on during the freezing nights!

[H2O]

Run an extension cord, and place a shop light in your bilge to heat it until you can winterize it. Is the boat stored indoors or out?
Good idea, thanks.
The boat is stored outdoors. (under some oak trees, under and a-frame style tent, and covered so it doesn't "radiate heat to space" at night). It's a good set-up for the shop light idea.
I think I'm out for the woods for now, because we're headed back to the 40's for nightly lows. As soon as I get back on my feet I'll fire it up and find out for sure, just sweating it a bit until I find out...

[ULTRA26 # 1]

I wouldn't be to concerned. The light is a good idea however. Hope your shoulder is feeling better soon

[Not So Fast]

Good idea, thanks.
The boat is stored outdoors. (under some oak trees, under and a-frame style tent, and covered so it doesn't "radiate heat to space" at night). It's a good set-up for the shop light idea.
I think I'm out for the woods for now, because wer'e headed back to the 40's for the nightly lows. As soon as I get back on my feet I'll fire it up and find out for sure, just sweating it a bit until I find out...
Phebus has the right idea but if its sitting outside then you better make some arrangements to keep'er warm IMO. :idea: NSF

[572Daytona]

If you have a local BoatUS or WestMarine you could buy an engine compartment heater. They are thermostatically controlled and turn on only when they temperature gets down to a certain point. Similar idea to the shop light in the bildge but they are also ignition protected if you have a closed compartment. A bit pricey but they do offer convenience and peace of mine. I have one in my Cruiser that I leave at the dock all winter in North Georgia were we see temperatures in the teens and 20's pretty often.

[Jim W]

H2O,
I winterize/summerize about 50 boats each year as part of my storage business.
It has to get down to the mid 20's to get the water to freeze hard enough to pop a block or exhaust manifold.
It's kind of like a puddle of water. If the puddle is frozen to where it is just mush and you can break it when you step on it, no problem. If it's frozen solid and hard enough to where you cant break it, that's a problem......
I have converted my customers boats to a plastic drain plug which goes into a brass fittting where the 1/4'' drain plug used to be. 1/2 a turn and they are out. I can get the Morgan Marine part # if you want. The factory is using them now and even putting them in the rubber water pump hose. Dont forget to poke a nail into all the drain holes in case rust/sludge is blocking the hole.
Be good, Jim

[WestTNRiverRat]

I don't think you have much to worry about if that is as cold as it gets. It will need to get down to the mid 20's and stay there a few days to really freeze it hard. Don't forget about your outdrive either. You will get water in the lower unit and if there is a hard freeze it can crack the lower unit housing. Don't know if you've ever priced those, but you don't want that to happen. I always drain my lower unit in the fall and put new gear lube in the next spring.
HTH YMMV