Temperature at which a block will crack

aero3113

Im just wondering how cold and for how long it has to be to crack a block. I ran my boat the other day so no more antifreeze in it. Now the early mornings are getting below freezing. Last night I ran it and figured it will stay warm to prevent freezing. This week is supposed to be warmer. 

randy56

If its setting in the water, real cold. Thermo keeps it warmer that out of water.

aero3113

It's out of the water in my back yard.

Handymans342

I have never seen cast iron welded with any success. 

Handymans342

I have heard many ways of welding cast. Aluminum may be easier. 

aero3113

I don't think it was cold long enough this morning to do any damage and it was close to 50 today. I just ran the boat up to temp and didn't notice any cracks or water in the oil. Was searching the net and came across this. Very interesting:
http://ultramarineperformance.com/engine-pinning/

randy56

easy test, put a cup of water on top of spark arester, or somewhere easy to see, check it in the am. I used to put a drop lite in the engine compartment when worried, lite puts off heat, Now it will not work when its real cold. but if you get up to 50 during the day you should not have a problem.

aero3113

Yea, I just over analyze everything. I guess that comes from being an aircraft tech. Better safe than sorry!

Michael T

Where I am cracked blocks are a way of life if anything goes slightly bad. The areas of the block that are particularly vulnerable are channels closer to the outside of the block. I'd get some heat in there. Waaay better safe than sorry. It's not just the cost of the repair it's often that it requires an R&R.

partlowr

temps would have to stay below freezing for days to freeze and damage your block. The actual temp doesnt matter, freezing is freezing. If you are concerned buy a clip on flood light and one of those heat bulbs and run an extension cord to it and shine it down in your engine compartment, just make sure its not touching anything that will catch fire. 

Michael T

....I would buy a cheap marine certified heater. they aren't expensive. Because of the potential for freezing temperatures where I live earlier in the year my Insurance company spells it out real clear - any use of non-certified heating components in the boat voids any warranty claims for fire, water or freezing damages.

pault1216

I just open the 3 drain plugs and put my shop vac hose on the lowest one and suck it dry....hmmm...that gives me another great idea....

aero3113

I think this past Saturday night into Sunday morning was the only time I needed to worry. The forecast from now on looks a lot better 

Michael T

@aero3113, yeah you HAVE to be okay now! Geez what a nutty Spring! It's snowing here today again!

aero3113

Crazy!

LaRea

Drop lights?  Flood lamps?!  Seriously, do you guys not read Seaworthy Magazine?  

06Rinker270

I do all the time and I say no thank you to that.  Those pictures are scary man.

Dream_Inn

I've seen the certified ceramic heaters used which are made for boating and they are fine.  Not that I have a desire to use them, but they are made for the application.  I've seen many of those pictures (heck, I've had a fire on my boat) and I have to say people really do some dumb stuff. 

212rowboat

a lot of folks figure that getting all of the 'freezable' juice out is the better plan, but don't consider what happens to components when they are exposed to air all winter, and not submerged.  

the better plan is to use anti-freeze that has an anti-corrosive component, even if you have to add it, no? 

autos run closed cooling systems and the anti freeze has a component that creates a 'skin' on hard parts, which protect them from internal corrosion.  us running raw systems don't get to enjoy that.  that doesn't mean you can't store over the winter with something that does, though... just don't use standard auto coolant/anti-freeze... one drop of that stuff in the pond can contaminate it terribly.  

keep an eye on corn glycol... it foots the bill boaters need for antifreeze in a storage below freezing circumstance, it is absolutely safe to the environment, and it provides anti-corrosive properties to boot.  

that is what will be in my floater next winter for sure.  

reneechris14

I have used I halogen  (500 watt) shop light of the ground under the boat with good secession almost 15* difference.no risk of fire and my neighbors know I love my boat with a spot light on it

Cableguy Greg

Why not just drain the block? Pull the blue plugs and replace them when all of the water is out. It would give room for the remaining water to expand.

212rowboat

Cableguy Greg said:

Why not just drain the block? Pull the blue plugs and replace them when all of the water is out. It would give room for the remaining water to expand.

most the glycols in antifreeze/coolant provides a layer of 'skini' over hard parts, protecting them from corrosion and cavitation (little bubbles that act like sand blasting in this context).. raw water engines don't have this option- but when running isn't a threat much because the system isn't closed allowing boil (if any air is present) and the water doesn't stay in there long enough to even hint of degrading to acid (and attacking that skin)... we just go about our business cooling with one huge reservoir of coolant... 

that will not work out so well in storage if all the juice is gone- corrosion happens on a system when all the fluid is missing... I've seen water pumps seize, and interior of exhaust manifold spit out pure red water when the engine is first fired... 

which is the long answer to say- you can drain it ALL, and blow it out, and that will most likely be all you need to do to protect your engine over the winter- but filling it with proper percentage of antifreeze will reduce corrosion, and using antifreeze that has corrosion inhibitors is an even better solution... 

if I didn't run in saltwater i don't think i'd concern about this that much- but that salt is an excellent at doing really bad things to metals... thorough fresh flush and total blowing out is absolute minimum- the best being that + antifreeze and corrosion inhibitor of some type that won't pollute when you launch in the spring.  

Cableguy Greg

The OP was curious about his unwinterized engine. I agree 100% that rewinterizing is the way to go, but for a few nights that it got below 32, wouldn't draining it work? It would be better than leaving it full of water that could freeze. Just my 2 cents worth...

212rowboat

oh- I'm tracking now... yeah, I'm with you... blowing out any water (or just leaving the blue plugs out) ought to be enough for a couple nights at only around the freezing point... 32* doesn't penetrate like below 10* does... it takes time..