Originally Posted by milkmania
I'm just trying to picture the water passages..... if water is going uphill then goes downhill and there's a pocket of water that cannot be purged out, I'd think that it would freeze in there.... and if it was in a location that was tight, the only way for the ice to expand it for something to break.
take for instance the 1/2 inch block plug..... is it at the very bottom of the water passage, or is it an inch above the passage? If it's above, then you've got an inch that'll freeze. then you've got the nose up tilt of the engine block..... what about the water from the plug to the back of the block?
Maybe I'm overthinking it.... but if this were the case, seems like PCM, Indmar, and others would lust have the valves in place to begin with.
I think you are over thinking things slightly.
When the water freezes it has to go somewhere. Say we use the 1" gap from the drain to were the water catches or in some kind of valley where water sits. When the water freezes it will expand and it will find its way out through the valley or the passage that now is not blocked due to have drained.
If we take a metal dog bowl or say a cattle watering tank and let it freeze. Why does the metal not break or bust. Why do the plastic ice cube trays that you freeze for ice for cold drinks not break?
The water is not under pressure with the block drained. Therefore the passages are not under pressure and the water has somewhere to expand to.
As far as the Tstat, you are supposed to drain the hose running from the tstat housing to the water pump.