Just what determines how much anti freeze is enough. I know that water will freeze at 30degrees. How cold does it have to get to be a real danger.How long does it take for a fully warm engine to cool down. just wondered. I just replaced the termostat and there is nothing but water in the engine. It is supose to get to 20 degress tonight, but the van is sorta between the house and shop and at 1230 am I plan to let it run till its warmed up .......

 

No way to tell, there are too many variables. You will just have to start it every hour or so until you get a 50/50 mix back in it. Put a blanket etc over the hood and grill to help keep the heat in.

 

I suppose you could drain the system again and refill in the morning.

 

I'm sure you know by now whether your block survived the night but I am guesing you were fine. Assuming you got your water up to 190° at midnight like you mentioned and didn't touch it again, you would have 7 or so hours before the outside air temp starts to rise again. Getting the water from 190 down to 32 takes a good amount of energy loss. Getting it to freeze is another matter. It takes a lot of energy being removed from a quantity of water to go from 32° (liquid) to 32° (solid, as in ice). 20° probably isn't a large enough temperature differential to get the water to freeze in just 7 hours.

Hope I'm right.

 

Those antifreeze testers with the floating ***** are pretty cheap.......cheaper than an engine block anyway.

Steve

 

Most every container of anti freeze I've seen, has a chart on it showing the amount needed.
In most cases, a 50/50 mix is good.
According to my genuine Prestone° jug, a 50/50 mix gives you protection to -34F.
70/30 gives you -84F

 

I had no problem. It takes alot for an engine to hard frezze but Im going to put some antifreeze in today , thanks

 

> Just what determines how much anti freeze is enough

If you do not have the money to refill the whole system, then two gallons of 50/50 mix should be enough diluted with water to get you by.

Just run the vehicle until it gets hot enough to open the thermostat.

> How cold does it have to get to be a real danger

I agree with the 20 degrees, wind is a big factor. If you put cardboard in front of the radiator that will retain the heat much longer. Just a trick when you go hunting or something where the vehicle will sit while you are out of the truck.

 

The real danger is trying to "get by" and hope nothing happens. I usually don't get the clean end of the stick on those occasions.

Hope everything came out alright...

 

Glad to hear your 'Star survived the night. Because you didn't open the block drains you had some antifreeze mixture trapped in there (if it was there before), but 20* is pushing your luck.

Steve

 

Wind speed and direction is a BIG factor, as well as temperature. That is why it is impossible to quantify how long it will take to freeze.

 

I solved the problem I think,Tonight I will park it in my heated garage. Sorta tight with my fairlane hoggin up the place but a short aerostar doesnt take up much room...

 

You know.....you could've had a jug of 100% in it by now....

 

Anti-freeze also helps cool the engine and keeps it from boiling over, fights corrosion and is usually a requirement on A/C equiped vehicles.