Draining block - Leave open or closed

[suprasam]

I partially winterized yesterday, well when I say partially I actually only drained the block, I didn't have a chance to stabilize the gas or change the oil. My question is, I left the drain plugs open.....does it matter open or closed?

[kvand347]

You are now going to start a debate!! :)

There are two thought processes...well, maybe three...neither one is wrong.

1. Drain block, manifolds, hoses COMPLETELY and leave plugs off (lubricate threads with grease, anti-seize, etc so they don't rust during lay up).
2. Drain all of the above, fill with anti-freeze, leave plugs in.
3. Do #2, but then drain anti-freeze as well

If you are only doing #1, make sure to raise and lower your tongue to try to get all water out...or tow boat up/down a hill...

[kvand347]

FWIW--I use option #2 as I live in FRIGID Wisconsin and just like the added corrosion protection RV anti-freeze provides.

[crystal waters]

I have alway used option #2. Done correctly it removes all doubt and as kvand347 mentions ---it gives added corrosion protection.

[suprasam]

Filling with Anti-freez.....by doing this, are u taking ur intake hose off, and pouring into there and turning ur motor over? I have a feeling someone is gonna smack me in a minute....

[kvand347]

You pour the antifreeze through the upper hose on the raw water pump. Bend the hose up and pour in 3-4 gallons until you hear it coming out the exhaust. No need to run the motor. It will flow past the thermostat as long as all the water is out of it.

8153

[suprasam]

Thanks for the help! I do plan on changing the oil.....but I just haven't had a chance to yet, and I dont want a very cold night to reach up on me without atleast getting all the water out. This is the one thing I hate about having an inboard......the drive sits so low I can't back it up my long ass drive to fit in the garage. So I have to work on it in the weather.....Oh well, I love this boat!

[kvand347]

Thanks for the help! I do plan on changing the oil.....but I just haven't had a chance to yet, and I dont want a very cold night to reach up on me without atleast getting all the water out. This is the one thing I hate about having an inboard......the drive sits so low I can't back it up my long ass drive to fit in the garage. So I have to work on it in the weather.....Oh well, I love this boat!

Agreed! It can be a pain in the butt, but it is well worth it in the end. My tower is not collapsable so it doesn't fit in my garage either...we had a nice weekend so I got it done and in storage already.

[michael hunter]

Most cracked blocks happen in the south. Its easy to get lazy with such light winters. If you have ended your season then go ahead and do a proper winterizing just like its in the north.
I recommend filling it with antifreeze. Even though you will get away with it 90% of the time by just draining you can still get some water trapped in passages and cause damage.
My motto is too much is never enough.

[beast 496]

We winterize over 300 boats a year, We always drain and then flush with a marine, non toxic antifreeze. We leave the blocks dry and plugs out. In the spring, we simply summerize, install the plugs, test run, and deliver. We have not had a frozen engine ever doing this process. Al

[kvand347]

We winterize over 300 boats a year, We always drain and then flush with a marine, non toxic antifreeze. We leave the blocks dry and plugs out. In the spring, we simply summerize, install the plugs, test run, and deliver. We have not had a frozen engine ever doing this process. Al

Just curious as to why you drain the anti-freeze. I know other people do it as well, but the marine stuff is good to -50*. From what I've read, the marine stuff will not expand. Just seems like a waste of anti-freeze if you're just going to drain it. I'm open to anything though!

[cadunkle]

I normally drain water (pull all plugs), then run 4-5 gallons antifreeze through it after pulling thermostat, then pull all plugs again, clean bilge, remove all water, clean etc. and leave plugs out block drained until spring. Paranoid maybe but it makes me feel safe.

This year I think I'll be pushing past when we get freezing temps at night. What do I do with boat stored outside covered up? Not worry abotu a dip below freezing overnight and do nothing? Run it to temp at sunset and leave it to stay warm overnight? Drain block after every use? Drain block and pull all hoses for raw water pump and heater? I don't know? Don't want issues from freezing but being as I want to push this season it makes it difficult not having heated storage before I winterize.

[kvand347]

I normally drain water (pull all plugs), then run 4-5 gallons antifreeze through it after pulling thermostat, then pull all plugs again, clean bilge, remove all water, clean etc. and leave plugs out block drained until spring. Paranoid maybe but it makes me feel safe.

I guess I still don't understand why some people pull plugs after filling with anti-freeze?? Are you worried that it will freeze/expand? Just wondering because mine is sitting with antifreeze in it right now and was not planning on draining it. Aren't you asking for corrosion when draining the block and leaving it open since there is no anti-freezef left (over very little)?




This year I think I'll be pushing past when we get freezing temps at night. What do I do with boat stored outside covered up? Not worry abotu a dip below freezing overnight and do nothing? Run it to temp at sunset and leave it to stay warm overnight? Drain block after every use? Drain block and pull all hoses for raw water pump and heater? I don't know? Don't want issues from freezing but being as I want to push this season it makes it difficult not having heated storage before I winterize.

At minimum I would pull the block plugs. I figure a cracked block is more expensive than exhaust manifold/hoses...

I've heard some people will leave a space heater or tap light on in the engine bay...not sure how much a light bulb will do for warmth on a cold night. Space heater sounds dangerous with gas lines so close.

[wotan2525]

I normally drain water (pull all plugs), then run 4-5 gallons antifreeze through it after pulling thermostat, then pull all plugs again, clean bilge, remove all water, clean etc. and leave plugs out block drained until spring. Paranoid maybe but it makes me feel safe.

This year I think I'll be pushing past when we get freezing temps at night. What do I do with boat stored outside covered up? Not worry abotu a dip below freezing overnight and do nothing? Run it to temp at sunset and leave it to stay warm overnight? Drain block after every use? Drain block and pull all hoses for raw water pump and heater? I don't know? Don't want issues from freezing but being as I want to push this season it makes it difficult not having heated storage before I winterize.

I always figure that if it's not cold enough to freeze a pail of water solid, it's not cold enough to freeze your boat. That being said -- if you have electricity, a small 110v heater would be cheap insurance and keep it plenty cozy under that cover.

[beast 496]

The way we do winterize, with adding the extra 2 gallons of marine antifreeze and then letting it flush out the block and manifold, is a process that works for us. Just an extra amount of safety. Plus, we don't have to remove any hose fittings from oil coolers, the sea water pump is saturated in marine antifreeze, which lets the impellor be lubricated upon spring start up. Once we pull the drain plugs, we do not reinstall for running of the antifreeze.
If you want extra fall security without wanting to drain the block all the time, I suggest a block heater, basically you buy a block heater that will take the place of a core plug. This is the same type as optional equipment from GM. You can buy at most auto parts stores. This will keep the block over freezing conditions with the motor hatch down. In my Suburgan, it will keep the coolant warm to the touch even in the dead of winter. Al

[cadunkle]

I guess I still don't understand why some people pull plugs after filling with anti-freeze?? Are you worried that it will freeze/expand? Just wondering because mine is sitting with antifreeze in it right now and was not planning on draining it. Aren't you asking for corrosion when draining the block and leaving it open since there is no anti-freezef left (over very little)?

I use RV antifreeze which does not have the same corrosion inhibitors are regular automotive antifreeze. RV antifreeze will also freeze and turn to icy slush well before the rated temp at which is freezes solid, and it doesn't take much water mixed in to drastically reduce the freezing temp. I feel safer draining it all out after running it through, in that the RV antifreeze will be mixed with some water and most of that comes out. Without a block full of liquid and with drain plugs out there is room for any remaining water or antifreeze to expand without doing damage.

Call me paranoid, but I lost a SBC to freeze once. At least I suspect I did. I realized in spring I did not get all the water out. I had a busted leg from a motorcycle accident and had a friend do the winterizing. Poured it full of RV antifreeze and suspect it froze. Was fine first time out for a few hours but second time out that season it broke down and milkshake everywhere. My best guess is freeze did it... hence my paranoia about freeze damage and residual water.

[wotan2525]

I've been using RV antifreeze (and not draining it) for 10 years in northernish WI where we see an honest -25F every winter. Never had a problem. Everyone seems to have their own method, but I'm going to stick to mine. ;)

[Salty87]

This year I think I'll be pushing past when we get freezing temps at night. What do I do with boat stored outside covered up? Not worry abotu a dip below freezing overnight and do nothing? Run it to temp at sunset and leave it to stay warm overnight? Drain block after every use? Drain block and pull all hoses for raw water pump and heater? I don't know? Don't want issues from freezing but being as I want to push this season it makes it difficult not having heated storage before I winterize.

depends on how warm it's been prior to the freeze, how cold it will get, and for how long it will be that cold. our engines are insulated very well. it takes some time for the cold to penetrate enough through the hull and engine cover to freeze fairly thick iron.

the early fall overnight freezes where temps start in the 50's or 60's and get back there as soon as the sun shines isn't a problem. you have to worry when the day isn't any warmer than 40's before the freeze and it won't warm back up for a while. in that case, there's been enough time for the ambient temp of the block to drop closer to the freezing range.

fill a jar or even plastic cup with some water. set it on the floor of your boat under the cover. check it first thing in the morning for ice. it has to be really cold for more than 8-10 hours to make ice.

disclaimer...i'm not advocating that any of you crazy northern dwellers not winterize, these are just observations from central tx where i haven't had to fully winterize every year. or, we'll get chances to take it out in Dec or Jan. Drain the exhaust (i have the ever-clogging petcocks), pull the lowest hose on the engine, run shower dry (do this first). then wait for good weather again.

[Blackntan90]

Well I winterized this past weekend, hated to do it so early,but lots of other stuff to do. Man am I glad I did it when I did- we have SNOW in the forecast for this coming weekend!

[docdrs]

After I drain my antifreeze I reinstall all plugs so then I'm ready to go in the spring. The knock sensor plug can be a real pita if left out. I left it out the first season and had to tap the block threads to get it back in in the spring due to the corrosion on the threads over the winter. If you leave them out I suggest you coat the the block threads with some anti seize or spray some fogging oil on them to prevent corrosion. Re installing with anti seize prevents any corrosion and seals up the lower block.

[86 century]

I am new around these parts having just bought a supra.
However I have been winterizing boats and jet skis for 15years.
It doesnt realy matter about if you drain the antifreeze or not I have done both and am yet to lose an eng to ice.
Good Luck

[csuggs]

I've been using RV antifreeze (and not draining it) for 10 years in northernish WI where we see an honest -25F every winter. Never had a problem. Everyone seems to have their own method, but I'm going to stick to mine. ;)

Same here. I'm in WV and the boat stays in my garage under cover, although not heated it does not get as cold in the garage as it does outside. The first year I placed a drop light in the bilge to create some warmth, but haven't done that for years.
My procedure is to drain all the water from the block and manifolds, then back the trailer down a steep bank near my driveway to drain the water out of the exhaust pipes below deck. Then I remove the hoses from both sides of the trans cooler, and the supply side of the raw water pump. Those hoses I drain and leave off for the winter. Also I remove and drain the sea water strainer basket. Then I remove the impeller and coat with oil to "relax" the rubber veins - the raw water pump is also left out. Then I remove the plug from the "J" pipe that supplies the water pump, allow to drain and re-install the plug. Then I pour RV antifreeze into one of the manifold hoses until it just starts to come out the block plugs, then I re-install the block plugs. Then I pour RV antifreeze into the manifold hoses until it starts to come out the manifold drains, and re-install the manifold plugs. All this takes about 2gal of antifreeze. Then I reconnect the manifold hoses and clean up the bilge. Close it up, clean it up, scatter some scented Bounce dryer sheets around the cabin and under the seats, and cover the boat. All set for winter . . . .

[wotan2525]

You guys all do far more work than I do.

I've got a hose T and valves @ my raw water intake. Here's my procedure.

Run engine on hose until warm. Shut off. Change oil, spark plugs and pull thermostat. Remove air cleaner. Disconnect house from supply and put in 5 gallon bucket full of RV antifreeze. Suck 4 gallons through and then empty 5th and 6th gallon into bucket while it's still running. Raise revs slightly and fog out engine through carb until it's ready to die. Time killing it with antifreeze almost being gone.

Antifreeze starts coming out the exhaust after about 3.5-4gallons have been sucked. I use 6 just because that's how many come in a carton.

I don't pull any freeze plugs or anything else. This method is simple and it works.

[docdrs]

Here are some facts about propylene glycol

Propylene glycol antifreezes are designed to provide burst protection to temperatures of -50° F or below. Ice crystals will start to form in -50 RV Antifreeze at temperatures around +10° F and will appear to be solid ice at around -10° F to -15° F. Propylene glycol based antifreezes continue to contract and will not expand until temperatures of -50° F are reached, thus providing burst protection for pipes.

There are several methods used by the marine dealers to winterize. You should refer to your owners manual for winterizing tips and recommendations. Some dealers use a VAT method where the outdrive is lowered into an antifreeze solution and the engine is run for a few minutes at operating temperature, making sure all the water is purged and the antifreeze solution is throughout the system. Another method requires the removal of the thermostat, opening of all petcocks to drain water from the engine block and then pouring the antifreeze into the engine block until the solution runs out of the petcocks.

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