Justin,
     That is correct. Even though we call them freeze plugs they were=20
never designed to protect the engine and usually they don't. Most of the=20
time if the coolant freezes it will break the radiator if you are=20
fortunate. If not it deforms or even cracks the cylinder walls.
     We have a lot of bad information floating around in the states=20
about cars and motorcycles. Like calling them motorcycles. They are for=20
the most part engine cycles but that is kind of awkward to say. The=20
prime mover in most cars is an engine, not a motor but supposed=20
knowledgeable people still call them motors. True there are now cars=20
with motors in them either as a hybrid setup or even as the only driving=20
force. We even call it motor oil and yes it can be used to lubricate=20
motors but for the most part it is used in engines.
     And then there is the one about if you set a battery down on a=20
concrete floor it will ruin the battery. This is not true. It used to be=20
when the batteries were made with wood cases.
     Or if you leave the thermostat out the engine will run hot because=20
the coolant is going too fast to pick up the heat. This violates one of=20
the laws of thermodynamics and I don't remember which one. The reason it=20
runs hot is because most cooling systems have a bypass hole so that=20
coolant will circulate through the engine when the thermostat is closed.=20
If the thermostat isn't there hot coolant is being directed right back=20
into the engine without going through the radiator. On some engines the=20
hole was only about a quarter of an inch in diameter. In some engines=20
the hole could be close to two inches. That is a lot of coolant that=20
never makes it to the radiator.
     Then there is the worst one of all. A person has a small leak=20
somewhere and they believe that as long as they keep the cooling system=20
full everything will be OK! NOT so. This will cause bubbles of air to=20
form in different parts of the engine and in passages in the cooling=20
system. These air pockets act as insulation and they will cause local=20
over heating. These hot spots will not show up on the temperature gauge=20
but the damage is being done. Also the pockets of air can interfere with=20
the circulation of the coolant and this will cause general overheating.=20
Also with a sealed system the pressurization of the system can't take=20
place which raises the boiling of point of the coolant. The final damage=20
is the pockets of air cause cavitation and allow oxygen in to the system=20
which causes corrosion.
     So there is a lot of bad info out there. But it is fun to listen to=20
and then just stand there and shake your head at. :)
Thanks,
rich!
P.S. I just learned something new. There is a strong drive on to try and=20
switch over to a hydrogen based system. Well hydrogen is the smallest of=20
all molecules and it is almost impossible to build a container that=20
doesn't leak. It is also the lightest and least dense of all molecules.=20
So as you increase the pressure to try and put more and more hydrogen in=20
to a container which directly affects range the storage problem becomes=20
even more difficult.
     So here is a scenario to think about. Whoever fills their tank up=20
and parks at the airport in a semi-enclosed parking structure The=20
vehicle is sitting there with the hydrogen slowly leaking out of the=20
tank. The best case scenario is this person gets backs after a couple of=20
weeks and the tank is empty. The worst scenario is that someone is=20
walking by the car and pulls out a match to light a cigarette. The=20
parking garage ends up in the adjoining counties. Just something to=20
thing about.
Thanks,
rich!

On 11/22/2014 2:51 AM, Justin Richards wrote:
> Thanks rich,
>
> I can imagine from your explaination that there's many stories of people
> driving of without unplugging first.
>
> And wrt the plugs I take it from the description it is what I know as a
> welch or core plug that are used to plug the holes that the moulding sand
> is poured out of.
>
> Cheers Justin
>
>>       There is another type that is inserted in to the engine block in
>> place of what we Americans call a freeze plug. I believe you folks call
>> it a soft plug. Again you plug it in at night and it will keep the
>> coolant at about freezing in 30 or 40 degree f below zero temperatures.
>>

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