c***@yahoo.com
2010-02-19 06:03:43 UTC
For those of you who have not spend a COLD winter somewhere,
you really can't imagine what it's like for your car.
When I say cold, I mean, when -20 degrees celcius is common.
And -30 C occasionally. Plus wind chill that can and will
give your face or fingers frostbite in MINUTES if
they are not covered up. There are many reports of homeless
people freezing to death up here.
-40 Celcius = -40 farenhite, so you should get the idea
how cold I'm talking about if you think in farenhite.
One big thing is that rubber actually expands in the cold,
unlike other elements.
http://www.fas.harvard.edu/~scdiroff/lds/ThermalPhysics/ThermalExpansion/ThermalExpansion.html
"Rubber is a solid that contracts upon heating. A large rubber band,
held taught by a
suspended mass, will contract when heated with a heat gun"
http://www.scienceforums.net/forum/showthread.php?t=35450
"Rubber is another material that tends to contract upon heating.
Long molecules, stretched when cold, but bent when heated."
Find some experiments here:
http://scifun.chem.wisc.edu/homeexpts/rubberband.html
When I lived in the middle of Canada before and fixed the Fords,
we had a number of issues.
New alternator belt installed in the summer, worked fine til winter.
It needed to be re tightened in winter. Because the rubber belt
had lengthened in the deep cold.
Tire pressure goes way down in winter. From 32 to 20 PSI or less.
More air needs to be added when it gets cold.
And bled out in the spring.
Because in winter, the rubber tires expand, at the same time
the air contracts.
But first, you have to be careful to bleed the air hose of any
water vapor, because it will freeze in your valve otherwise.
Then you can't fill or deflate your tires until it's warm.
Once I didn't bleed the tires soon enough in the spring. The
tire pressure went over 45 PSI. On the summer road trip, even
though the pressures were back in spec, one tire blew out.
Fortunately, I avoided an accident.
Another effect in really cold weather, -25 celsius and lower.
Rubber tires on some aluminum rims just won't hold an air seal.
Because the aluminum contracts, and the rubber expands.
This happened on a co worker's Miata. He returned to the
shop multiple times. Some people will just give up, and get steel
rims for the winter. Steel has less thermal expansion/contraction than
aluminum.
Another effect, unrelated to rubber. The oil in the car will
freeze like hard ice cream. This makes the engine very difficult
to turn over fast enough to start. AT the same time,
the strength of the battery has gone way down in the cold.
On really cold days, if it didn't start on the first few
tries, forget it. The battery had no more juice to
push through the hard oil, and the crankshaft
doesn't even turn. The solenoid just clicks. So, we used at
least 600 cold cranking amps. And rebuilt the carb in the
summer, so that it worked perfectly the first time in the winter.
That's why we have block heaters, which boil the antifreeze,
which melts the oil. Someone suggested that we change
our license plates to say: In block heaters we trust.
Another problem: gas lines getting frozen. After I drove
my car back to Canada, the southern windshield wiper
antifreeze froze up, even though it was rated to -20 C.
I had to park the car in a heated garage for a day to
get it to work again.
If you like, you're welcome to come try a winter up north.
You can do what I did once. I'll take you to the junkyard at
-30 celcius. You can lay on your back on the cold ground,
and pull out a power steering rack. BTW, many of the operations
require bare hands, because many things you can't do
through your gloves or mitts!
So unless you have spent a cold winter as I've described,
you're just a cold weather virgin, with no experience yet. :)
you really can't imagine what it's like for your car.
When I say cold, I mean, when -20 degrees celcius is common.
And -30 C occasionally. Plus wind chill that can and will
give your face or fingers frostbite in MINUTES if
they are not covered up. There are many reports of homeless
people freezing to death up here.
-40 Celcius = -40 farenhite, so you should get the idea
how cold I'm talking about if you think in farenhite.
One big thing is that rubber actually expands in the cold,
unlike other elements.
http://www.fas.harvard.edu/~scdiroff/lds/ThermalPhysics/ThermalExpansion/ThermalExpansion.html
"Rubber is a solid that contracts upon heating. A large rubber band,
held taught by a
suspended mass, will contract when heated with a heat gun"
http://www.scienceforums.net/forum/showthread.php?t=35450
"Rubber is another material that tends to contract upon heating.
Long molecules, stretched when cold, but bent when heated."
Find some experiments here:
http://scifun.chem.wisc.edu/homeexpts/rubberband.html
When I lived in the middle of Canada before and fixed the Fords,
we had a number of issues.
New alternator belt installed in the summer, worked fine til winter.
It needed to be re tightened in winter. Because the rubber belt
had lengthened in the deep cold.
Tire pressure goes way down in winter. From 32 to 20 PSI or less.
More air needs to be added when it gets cold.
And bled out in the spring.
Because in winter, the rubber tires expand, at the same time
the air contracts.
But first, you have to be careful to bleed the air hose of any
water vapor, because it will freeze in your valve otherwise.
Then you can't fill or deflate your tires until it's warm.
Once I didn't bleed the tires soon enough in the spring. The
tire pressure went over 45 PSI. On the summer road trip, even
though the pressures were back in spec, one tire blew out.
Fortunately, I avoided an accident.
Another effect in really cold weather, -25 celsius and lower.
Rubber tires on some aluminum rims just won't hold an air seal.
Because the aluminum contracts, and the rubber expands.
This happened on a co worker's Miata. He returned to the
shop multiple times. Some people will just give up, and get steel
rims for the winter. Steel has less thermal expansion/contraction than
aluminum.
Another effect, unrelated to rubber. The oil in the car will
freeze like hard ice cream. This makes the engine very difficult
to turn over fast enough to start. AT the same time,
the strength of the battery has gone way down in the cold.
On really cold days, if it didn't start on the first few
tries, forget it. The battery had no more juice to
push through the hard oil, and the crankshaft
doesn't even turn. The solenoid just clicks. So, we used at
least 600 cold cranking amps. And rebuilt the carb in the
summer, so that it worked perfectly the first time in the winter.
That's why we have block heaters, which boil the antifreeze,
which melts the oil. Someone suggested that we change
our license plates to say: In block heaters we trust.
Another problem: gas lines getting frozen. After I drove
my car back to Canada, the southern windshield wiper
antifreeze froze up, even though it was rated to -20 C.
I had to park the car in a heated garage for a day to
get it to work again.
If you like, you're welcome to come try a winter up north.
You can do what I did once. I'll take you to the junkyard at
-30 celcius. You can lay on your back on the cold ground,
and pull out a power steering rack. BTW, many of the operations
require bare hands, because many things you can't do
through your gloves or mitts!
So unless you have spent a cold winter as I've described,
you're just a cold weather virgin, with no experience yet. :)