Winterize engine in a bubbling slip?

Scott T-Bird · Oct 10, 2012

If the water isn't moving, it's freezing. The water inside the intake line and engine would freeze for sure. Yes, you must winterize just as if you were on stands. If you really think you will sail, I wouldn't run the engine and have to start all over winterizing again afterwards. My 1GM doesn't like to start anyway once the temps drop into the 40's or below.

Rob19574 · Oct 10, 2012

You need to winterize the engine the same way you would if it was on the hard. I wet-store too in North East. Is it raw water cooled? If so, just disconnect the raw water intake from the seacock (with that seacock closed obviously) and run that line into a bucket of Antifreeze. Make sure your engine is good and warmed-up so you have the thermo-open. I usually run my engine for 15 minutes, shut down and drain the block of raw-water. Then restart and run antifreeze through. In any case, just make sure after you run the antifreeze thru that its in all areas of the block (head, cylinder and exhaust system). I can check the block zinc and briefly open the block-drains to confirm antifreeze is in there. I use the pink stuff rated for engines. Then after that is done, change the engine oil and spray down your engine/trans with some WD40 or CRC. That is my engine procedure and its worked well for the past 10 years. I like to clear seawater out of the seacock and pour some antifreeze into it before replacing the raw water intake line.

Its a simple process and can be done in about an hour.

- Rob

Ron20324 · Oct 10, 2012

Igetit said:
Anyone have experience with bilge heaters? My marina is offering rental units as an option.

That's a nice option... until the big storm comes and knocks out electrcity... then comes the freeze.

Click to expand

RichH · Oct 10, 2012

Just consider what happens during a power failure during a severe winter storm ... and the 'bubblers' are not working due to the lack of AC power. Or what happens during an errant ice flow or 'break up' of ice which 'jams' towards a shoreline, etc.

Not only the engine, but the drains and through hulls MUST have 'antifreeze' added to prevent 'bursting' due to freezing.

Barnacle Bill · Oct 10, 2012

Oh, you mean they don't bubble in boats in Florida? What if the bubbling system fails? Like there is a power outtage or something? Good to have a back up if that happens and that back up is winterizing your engine and other systems. Also, I have seen bubbled in boats have their seacocks freeze and then the boat sank when it burst from freeze expansion. So.....winterize your seacocks too. An O'Day 272 is so easy to pull, not sure why you wouldn't, but then that is fine. Do as you may, but prepare for the worst because when you are not prepared, that is when the worst will happen.

anchorclanker · Oct 10, 2012

If the engine cooling system is completely above the waterline, it may be possible to put extra drain cocks where needed to completely drain the block, head and manifold, or any other low spot. Many marinized engines engines have the drains needed, but it pays to inspect carefully. If needed it is not difficult to drill and tap an iron block into the water jacket to add a drain cock. It the engine is below the waterline, it gets much more complicated, but is still probably doable.

Any water sitting in the engine can freeze, and it doesnt have to get to -zero to bust it, it only has to stay frozen a while. If there is enough water in the block or head or wherever, and it freezes, it will most likely rupture it and destroy the engine.

It is not enough to simply open the drains and walk away however. Rust and other sediment settles to those lower spots and will clog the drain. Guys forget this or dont know about it, but you should ALWAYS probe the drains with a wire to make absolute proof positive they drained. Every spring there are a raft of boats with cracked blocks that have the drain cocks open, so be aware.

RichH · Oct 10, 2012

anchorclanker said:
If the engine cooling system is completely above the waterline, it may be possible to put extra drain cocks where needed to completely drain the block, head and manifold, or any other low spot. Many marinized engines engines have the drains needed, but it pays to inspect carefully. ....... SNIP ........ there are a raft of boats with cracked blocks that have the drain cocks open, so be aware.

I would recommend that simple draining is NOT a good idea, especially for engines with cast iron blocks and cast iron exhaust systems. The problem being the introduction of moist air during long term layup promotes the formation of 'slab rust' which is quite destructive to cast iron. Better to fill the engine internals with antifreeze with adequate rust inhibitors ..... OR periodically fill the engine with water and RUN and then 'heat soak' the engine at high temperature so that the deposition of 'black/blue' ferrous rust is enhanced. Ferrous (black) rust is 'protective' vs. steel and cast iron. Slab Rust, or plateletized ferric (red) rust is VERY destructive because is can form 'between' the casting stratifications and literally PUSH the casting internals apart.

Rx.: Dont drain a cast iron engine and leave it 'full of air', Much better to refill with antifreeze with rust inhibitors to prevent SLAB rust.
SLAB RUST and its formation is why large ships almost NEVER shut down their engines for more than a few DAYS.

Stu Jackson · Oct 10, 2012

Think of it this way: what happens if the power goes out? What's your boat and/or your engine worth to you? Unless you live very close by and can check it daily...

anchorclanker · Oct 10, 2012

Rich, I totally agree. For seasonal or long term storage, some treatment or antifreeze solution should be inside the engine. However, if the boat is being used occasionally, short periods sitting empty wont hurt it, and it wont be nearly as bad as freezing it full of water would, lol.

That slab rust also has a lot to do with whether your running in salt water, or acidic/polluted fresh water through them as well. Ive seen some FWC engines up in Minnesota over 30 years old, drained and left dry all winter that still looked fine inside. This lake down here, while very clear, seems to have some real corrosion potential. Ive seen a couple outboards here with the lower units rotted right through, like swiss cheese. Not sure if it was caused by some electrical discharge, but seemed pretty odd for fresh water.

Tim R. · Oct 10, 2012

One nice thing about living in a commercial harbor is that it rarely freezes over. We get enough traffic every day from fishing boats, tankers and tugs to keep the water soft without bubblers.

I agree with most everyone else. Winterize it. I do not winterize my engine because my boat heater is in the engine compartment which keeps it in the 40s on the coldest days. I do run my engine in gear at least once a month.

RAD · Oct 10, 2012

I used to leave Free Spirit in the water here in NY year round and this was my way of winterizing my fresh water cooled diesel
Removed hose from raw water sea cock and placed in 1 gallon jug of pink anti freeze and started engine till jug was empty....now I know that 1 gallon is enough to have pink stuff coming out the exhaust, then I would put the hose back on so that in the event I wanted to go sailing on a nice day and there were plenty of those days.
In the cabin were 5 extra gallons of pink stuff to re winterize the engine after a sail
I did experience no power once during a nor'easter and all that happened was thin ice that broke up easy when the bubbler's came back on

Manureva · Oct 10, 2012

i used to take care of the fleet diving unit ribs in Halifax year round, they stay in the water year round, the only thing preventing freezing was a little heater plug on 120v that you can buy for 20 dollars. all sea cock left open as boat are to be ready at any time. we checked and runned them daily.