It's supposed to be 1deg. tonight and wind chills in the -5 to -10 range.

LT1 bird is in non-insulated 3-car garage next to external wall.

Radiator removed in October. Water system flushed by running water from the top of the block (t-stat location) and draining out knock sensor and other drain plug. I then let all the water drain and refilled with straight anti-freeze.

Engine has never been turned over since rad was removed, just refilled, so no water pump action to move the coolant around.

What are the odds of the block freezing/cracking? What can I do to prevent it?

TIA!!!

Do you have a thermometer out in the garage? Does it actually get below 32 inside?
My silly idea, if it does dip below freezing, would be to buy one of those little ceramic heaters, set it under the car near the block and turn on low, hood opened. In a safe manner if you can, don't melt the front end.
I'm not saying this is safe, just a potentially dumb® idea.

If you drained both sides of the block from the lower drain plug by the 3rd main cap (above the oil pan) and dumped anti freeze down into the block from the top and filled it, I really think it should be fine. If it hasn't frozen yet, it's not likely to start now. You could always drain it again to drain the anti freeze. My theory is that if the water jackets aren't full (or water can't freeze in a restricted space), it can't crack anything. So, the anti freeze should have already mixed with water and lowered the freezing temp of any remaining water. If not, having the water jackets empty will reduce the chance of water freezing in an enclosed space in the block and that should eliminate most of the potential for damage.

Interesting thought... I kinda ass-u-me-d that there would still be some pure H2O left in water jackets in the block, potentially causing a problem.

I like the heater idea, but just not with a heater. I'm thinking I'll use my magnetic work lights and stick one on each side of the block. That should keep the temp high enough to prevent freezing, I would think.

Thanks for the input.

If you've drained the water you're good. Anything left will have plenty of room for expansion. I occasionally just drain the block after the last event and put water back in the spring. This year I actually ran a gallon of antifreeze through it as it's still running & moving.

Sidney

I've heard that straight anti-freeze will freeze faster than a 50/50 mix. Is that true? Last year, I placed a small electric heater in front of my IT car to keep it from freezing. I only ran it at night when it got below 30 degrees, even though my garage has some insulation. The front of the car was on jackstands, and with the hood closed, just sitting it under the car seemed to keep it warm enough.

1. Put a 100 watt bulb in a drop light and place it near the bottom of the engine, turn it on and throw a heavy blanket or two over the whole motor with the light underneath. I've done this with the car outside and kept it from freezing.

2. Ethylene glycol at 100% strength will not freeze faster than 50/50 mix with water. What you gve up is heat transfer (cooling) capacity as the % glycol goes up. This is why straight water cools better that 50/50 mix in the summer.

http://www.amazon.com/Kats-1153-Handi-Heat...3032&sr=8-1

I have one on my car right now.

Pulled my old car out of the trailer today. It still has my motor and stuff that is going in the new car. Found a popped freeze plug.
Hope it is as simple as popping a new one in. If not, my season ended before it started.

be careful here. "freeze" plugs aren't made for freeze protection. They are present to aid in the manufacturing process. One purpose is to allow the sand to escape after casting, I also think they are used to locate and hold the molds in place during the pour, but I could be wrong about that, I've never worked at a foundry. If you've popped a freeze plug it is very possible you've cracked a head or two and/or cracked the block as well.

I totally understand that.
I had removed the radiator a week of two before. I knew it was going to dip below the freeze point, I didn't know it was going to stay there for over 24hrs. I may be F'ed, I know.

well we hope you're not F'ed. Maybe you should sprinkle ashes of 6 cat tails around the engine and say a prayer.

I just went outside and saw a nice puddle under mine? FML I hope its not bad but with the way things have been going I know it will be. I will let you know what I need soon in the classified section.

I worked in a foundry for a bit in college. The freeze plugs fill the holes where they connect the inside of the mold to the outside forms of the mold. If they weren't connected the mold could float in the molten metal and that's how you get "core shift" in a casting (or they made the mold wrong). So you make a mold of sand that has the internal shape of the water passages and it's connected to the part that shapes the outside of the engine block through little supports that are later machined to accept freeze plugs. Once it's removed from the mold, they shake the casting to get all the sand out (we had a huge table that had large springs pushing it one direction and a hydraulic or electric "ram" that hit it the other way causing a series of sharp impacts as it sat on the table. This shook the sand out of the castings (though we didn't do anything as large as engine blocks where I worked).

I seemed to have gotten of easy. No water in the oil.

That's what I ended up doing. 2 hand-held work lights on each side and a pair of 500w halogen work lights underneath. Then I closed the hood and made an offering to the racing gods. It's been ridiculously cold lately... -4 on Sat and -1 on Sun. Only had 8 out of 23 days get above 29deg in Jan. 7 days had lows below 10deg. Aren't we supposed to be on track in a couple months?!?

Any preference for steel or brass freeze plugs?

That sure is good news.