Date: Fri, 25 Jan 2013 18:40:07 -0800
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: Scott: common knowledge?
In-Reply-To: <5103377D.9050909@gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Being Friday ..
early 122's still had it I believe.. ( and 444's and 544's before that )
but certainly no 140 series or later volvo's.
re "I don't think automotive thermostat technology has changed much if
at all since the fifties. "
There are two significant advances in thermostat technolgoy since the 50's..
One is a 'two door' ..
or two pathway thermostat.
All waterboxer and diesel vanagons use this type of t-stat.
When one circuit is closed ( like the main-to-radiator circuit ) when
things are cold,
a 'bypass circuit' is open ..
allowing coolant to flow around and around in the engine , but not
through the radiator circuit.
as things warm up, the bypass circuit closes off, and the main circuit
opens.
the two 'doors' are on a common shaft..
so one opens while the other closes.
the other advance is having the thermostat on the bottom or 'return'
side of the engine.
VW diesel engines are arranged that way.
so are subaru engines ...
just improves temp stabiilty is my understanding.
and ....there may already be a few cars with the t-stat controlled by
the ECU.
scott
turbovans
On 1/25/2013 5:55 PM, JRodgers wrote:
> Early Volvos - the 544 series and some later - had a wind block built
> into the vehicle so that from inside the car you could raise and lower
> the wind block to deal with extreme cold air across the radiator and
> through to the engine. Not sure when they dropped it on cars coming into
> the US.
>
> John R
>
> On 1/25/2013 2:37 PM, Dave Mcneely wrote:
>> Jack, actually, you did post to the group. Your description of the
>> thermostat being able to modulate, and open just the right amount?
>> Whenever I've tested one in a pot of water on a stove, it opened
>> fully as the water heated, but as it cooled, it closed slowly, as if
>> it might be doing as you suggested. Maybe I got it too hot too fast
>> for that phenomenon to fully reveal itself on the way up, but the
>> cool down was more gradual.
>>
>> But, I have had the experience of very low temperatures and high
>> speeds keeping the temperature down on more than one vehicle. My
>> father's '53 Chevy had to have a wind block whenever the temperature
>> was below about 10 F. My camper benefits if the temperature is
>> around 0 F or colder, when driven at highway speed but is ok without
>> it at town speeds.
>> Just my 2 cents, and probably worth what you paid me.
>>
>> mcneely
>>
>> ---- Rocket J Squirrel <camping.elliott@GMAIL.COM> wrote:
>>> Hi Scott -- before I pester the group with a question that might be
>>> common knowlege, I figure I could pester you with it first?
>>>
>>> People write about putting cardboard in front of the radiator. I think,
>>> "I don't get it. The thermostat isn't an on-off switch, doesn't it open
>>> just as much as needed to keep the coolant at the right temperature? If
>>> the coolant coming back from the radiator is darn cold, won't the
>>> thermostat just crack open a bit?"
>>>
>>> Or maybe it does a poor job regulating temperature when it has to do
>>> that "crack open a little bit" thing.
>>>
>>> --
>>> Jack "Rocket j Squirrel" Elliott
>>> 1984 Westfalia, auto trans,
>>> Bend, Ore.
>>
>> --
>> David McNeely
>>
>
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