My Block Won't Freeze! .... Optimistic Thinking?

[UncleWillie]

I picked up an 18 ft bowrider with a 4.3l v6 last week.
It was sea trialed, throughly drained according to Merc, but not re-winterized with antifreeze.
The overnight temps have been in the 40's all week.

The temperature was forecasted to go to 28 Degrees last night.
The boat is in the driveway next to the house.
It's covered with a silver Poly Tarp.
The motor box has a 2 inch thick vinyl covered cushion on the top.
Folk wisdom says "Don't worry about it, It won't freeze that fast!"

True?

Well, being admittedly anal, and a self professed geek, Inquiring minds wanted to know.

I placed an electronic indoor/outdoor thermometer on the boat.
The outdoor long wire probe was routed through the intake vent grill above the transom, through the engine Oil fill cap, and inside of the engine.
The outside temperature was measured at the display head using the "indoor" switch setting.

At 8pm last night both the motor and outside air temp were in the lower 50's
At midnight, the Outdoor air was at 34 and the engine was at 48.
The temp bottomed at 26 at 7am (~Sunrise) according to my home weather station.
It is Saturday and I sleep in. So no 7am report.
At 10am (3 hours later) the outdoor air temp was up to 44 and the engine was reading 32 degrees!

This is a sample of one, so take it for what it's worth.
Your engine may freeze faster than conventional wisdom indicates.
Your experience will vary.
A trouble light under the engine is advisable for ANY freezing condition.

Now you Know!

 

[cr2k]

Re: My Block Won't Freeze! .... Optimistic Thinking?

If it was drained completely then there should be no problem.

 

[rbh]

Re: My Block Won't Freeze! .... Optimistic Thinking?

Why is it that no one ever thinks to install block heaters in their boats engine???


Probably because we never think we will be boating when it gets that chilly, but it happens.

 

[UncleWillie]

Re: My Block Won't Freeze! .... Optimistic Thinking?

If it was drained completely then there should be no problem.

I wasnt worried about the engine.
It is a newer MPI model with the single point drain system.
There is a drain manifold plumbed to about six spots in the engine.
You open one valve and remove two blue plugs to drain the engine.
The Merc Engine Manual does not mention adding any anti-freeze.
Next winter, I think I will anyway for good measure, and the Anti-Corrosion properties of Propylene Glycol.

I posted this info mostly for the folks that may believe a slight freeze will not penetrate the to heart of the block of an enclosed engine if it is only for a few hours.
Apparently, covered engines cool a lot faster than many believe.

 

[pevaguy]

Re: My Block Won't Freeze! .... Optimistic Thinking?

I don't think a block heater would protect the manifold(s) the riser(s) since the heated water won't be circulating through them.

 

[UncleWillie]

Re: My Block Won't Freeze! .... Optimistic Thinking?

I don't think a block heater would protect the manifold(s) the riser(s) since the heated water won't be circulating through them.

A 50watt Pad Heater on the oil pan may be just the solution to engines without any water in them.
Heat Rises.

 

[Mikeyboy]

Re: My Block Won't Freeze! .... Optimistic Thinking?

Yes uncle Willie heat rises and in my experience metal tends to be a good conductor for heat as well lol.

 

[GTS225]

Re: My Block Won't Freeze! .... Optimistic Thinking?

Heat Rises.

********************************************

No, it doesn't ! Heated air rises, and heated water will rise in a pool. Heat, the energy source, will eminate in all directions from it's source.

Roger

 

[ziggy]

Re: My Block Won't Freeze! .... Optimistic Thinking?

i don't get it.
forecast last night was for over night temps of 33*F. like usual, the weather man was wrong. it got down to 31*F. ok with me. i drained my block and manifold last week in anticipation of such incorrect forecasts...
bondo and others have made a believer out of me. air don't freeze. drain the water out of the cooling system and yer good to go for whatever the temps overnight are.
just drain it and be safe and done with it.

 

[UncleWillie]

Re: My Block Won't Freeze! .... Optimistic Thinking?

... Heated Air rises, and heated water will rise in a pool. Heat, the energy source, will eminate in all directions from it's source...

Point well taken!

The implications was that the heat source is best placed at the bottom of the engine, as the heat, through convection, will eminate upwards, through and around the engine, heating it much more completely than if one were to apply the heat to the top.

That little $15 stick-on heating pad looks like a cool (Warm?) option to me!
-

 

[Scott Danforth]

Re: My Block Won't Freeze! .... Optimistic Thinking?

a 60 watt drop light would keep the air warm under the engine cover.

 

[UncleWillie]

Re: My Block Won't Freeze! .... Optimistic Thinking?

a 60 watt drop light would keep the air warm under the engine cover.

This experiment coming soon! to a Forum near you.

 

[hungupthespikes]

Re: My Block Won't Freeze! .... Optimistic Thinking?

a 60 watt drop light would keep the air warm under the engine cover.

NO!!! That's a 7000 dollar misjudgement for me.

Don't trust anything that might work. Winterize, drain or replace the water everytime. When I winterize now I do both, flush the motor with the purple antifreeze stuff and drain. If there is any water left in the system then it's protected.
The price and time to do it right is nothing compared to the price and time of replacement.
huts

 

[Maclin]

Re: My Block Won't Freeze! .... Optimistic Thinking?

Any method that depends on a supply of electricity is a potential failure waiting to happen. What happens when someone kicks the cord out of the wall...or the breaker trips...or visitors turn off the switch in the utility room...or some one says Hey Look, I found an extension cord I have been needing, can't beleive it was just out here leading nowhere...

No experiment needed, no need to risk your engine to make a point. Just drain it, just sayin'...

 

[Scott Danforth]

Re: My Block Won't Freeze! .... Optimistic Thinking?

NO!!! That's a 7000 dollar misjudgement for me.

Don't trust anything that might work. Winterize, drain or replace the water everytime. When I winterize now I do both, flush the motor with the purple antifreeze stuff and drain. If there is any water left in the system then it's protected.
The price and time to do it right is nothing compared to the price and time of replacement.
huts

I have used the trouble light trick for years during late season over-nights when the boat is at the dock. my father has been using it longer for cars in winter on below zero days. Agreed that if your pulling the boat, drain it, however for the occasional low temp night, the 60 watt will keep the boat engine compartment about 60 degrees.

 

[Home Cookin']

Re: My Block Won't Freeze! .... Optimistic Thinking?

the question is about a one-time drop to a degree or two around freezing. In that case, a drop light should be all you need. Not talking about over winter or a drop to 20*.

For one thing, neither the weatherman nor your window thermometer is accurate within a few degrees. Your boat or whatever holds heat from the daytime. Does your unheated garage or shed match the outside night-time temps? no. So you need sustained temps a good way below freezing to bring that block down. Then it has to be the inside of the engine--and then the water in it, all of it, getting to 31* or less to freeze solid to do any damage.
cold wind is a factor (dissipates the retained heat faster). Is it breezy in your engine housing?
Try this next time they call for freezing, whether you are drained or not: fill a beer can with water and set it next to the engine. Check it in the morning to see if it's frozen SOLID. Not likely.

Hope you sleep better now. May as well be worrying about your hot water heater exploding.

 

[Chris1956]

Re: My Block Won't Freeze! .... Optimistic Thinking?

I have used the 40W heating pad under the oil pan, whenever the boat was still in the water. The air would get to below freezing, but the water and engine didn't freeze. I did it mostly to have warm oil for cold start up, during Striper season.

I would never try that trick with the boat out of the water. You need the residual heat of the water to assist the heating pad.

Not to start an arguement, but whenever I winterized my MerCruiser V6, residual water always came out of the block, when I introduced the antifreeeze. No matter how long I let her drain, there was always some water in the block and manifolds.

 

[UncleWillie]

Re: My Block Won't Freeze! .... Optimistic Thinking?

OK, Here is the latest from GEEK CENTRAL !!!

I ordered a Logging Temperature Data Recorder two weeks ago. ($9, China)
It will Log the temperature every minute for weeks on end.
My home weather station also logs the outside temperature for comparison.
The WX station and the logger have been calibrated together so that they agree.
The Logger spent the last four days tucked up next to the exhaust manifold inside of the covered boat.

Interesting results.

The engine gets 2 to 10 degrees F warmer than air temperatue during the day depending on how much Sun hits the boat. No Suprise!
At night the engine stayed 2 to 4 degrees F warmer than air temperature, except two nights ago ....

It was a clear sunny day so the engine got plenty warm in the Sun, 80+ degrees.
It was also a clear cool night.
The engine was consistantly 2 degrees F BELOW the air temperature.
It was still in the 40's so not a freezing issue.
I would never have considered that radiation cooling would be that effective in quickly cooling an enclosed, covered engine.

The temp is forcast for 34 degrees tonight.
I am about to go out and position the Temperature Data Logger again.
Tonight we test the 40 watt trouble light theory!

This is a great toy!

 

[Philster]

Re: My Block Won't Freeze! .... Optimistic Thinking?

You have earned 100 Geek credits for sure.

I've earned at least 10 just following this! :facepalm:

Why not a 60w or 100w bulb?

 

[UncleWillie]

Re: My Block Won't Freeze! .... Optimistic Thinking?

You have earned 100 Geek credits for sure.
I've earned at least 10 just following this! :facepalm:
Why not a 60w or 100w bulb?

And I thank you for the points! (It is alright to be a Geek as long as you know you are a Geek!)
I see that this thread has close to 900 views so there are a lot of closet Geeks out there!

I originally thought the 60 Watt bulb was going to be a little too much heat.
The back of my $3 trouble light gets way too hot to touch with a 100w bulb in it, so I was concerned about all that concentrated heat sitting on the hull under the engine.
I removed my normal 100w bulb from the light, but could not find a 40w bulb in the house, so 60w is what I had to use.
I went out with the trouble light and a small cookie sheet to place it on, to protect the fiberglass.
It turns out that doing, is a lot different than talking. No way that cookie sheet was ever going to fit under the engine.
A couple of 6 inch aluminum plates had to stand in.

It should be noted that the 60 watt bulb looked scarry bright under the engine.
I checked it a couple more times before going to bed to make sure it was not burning anything.
I kept asking myself, "Am I doing something completely Stupid?"
It sounds like a good idea, but it sure looks like a bad one.
If you anticipate having to do this, go buy a heating pad or a personal ceramic heater beforehand.
The trouble light would definitly be a method of last resort.

Now the results.
At 10 PM the engine was 50 Degrees F, the air was at 40.
At 3am the air bottomed out at 36 the engine had only dropped to 53.
At 8am the engine bottomed out at 51, the air had come up to 41.

Based on a sample of 1.
The 60 watt bulb was NOT overkill.
And can be expected to keep the engine about 10 degrees F above the ambient temperature.

Now we know.

If you think this is Geeky, Wait till you hear what I am doing with E10 Gasoline and Water!