Date: Thu, 27 Dec 2007 12:32:03 -0800
Reply-To: Scott Daniel - Shazam <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Shazam <scottdaniel@TURBOVANS.COM>
Subject: Re: Overcooling Hypothesis--Long
Content-Type: text/plain; charset="us-ascii"
Hey there , nice to see your comments.
I'm aware that blocking off radiator air might not help, but it's free and
easy to try, so why not.
On the idle switch thing, sure it would use a tiny bit more fuel.
And yes, if the idle switch doesn't make contact at idle it doesn't like to
idle as well.
That's why I suggest it for an experiment, and to only be used in long cold
docents.
There are quite a few things re-thought from the 1.9 wbxr to the 2.1. They
sure made a whole other thermostat arrangement.
If you study other cars you'll see more evolved thermostat systems. I
think a BMW 2002 has both inlet and outlet thermostat functions. You might
check into that - I think it's even in a hose, and not an engine fitting -
something in the back of my mind like that.
Also you'll notice all inline vw fours , gas and diesel, have the
thermostat on the bottom of the engine on the inlet, not at top on the
outlet. Subaru also does this.
Generally speaking a traditional thermostat on the top of the engine
doesn't give as good control of engine temps as more evolved designs do.
A few engines..........some corvettes I believe, even circulate water the
other way, in the top and out the bottom , all in the interests of
temperature stability, and thus emissions/drivability/fuel economy etc.
My point is a traditional thermostat at the top outlet of an engine is
old tech.
What I would look into is some sort of thermostat on the inlet
also.........explore that idea.
You might also consider some coolant bypass system.............like don't
route main circuit coolant to the radiator, route I right back into the
engine as soon as it comes out, like a 3 foot long route with no radiator
involved, something like that.
How about this one ...........just plain reduce flow volume in the main
circuit to the radiator ....big ole fat ball valve right where you can reach
it in flight ?
Just tossing out ideals. Need to think outside the box for new possibilities
and solutions.
I am always playing with engine conversions and cooling system layouts, and
a car that runs too cool downhill is terrible. A diesel is much worse.
AND ! ....tdi's run so cool that they have regular glow plugs in their
cooling system. 3 of them right at the outlet of the cylinder head. I am
saving one of those outlet flanges and glow plugs. I'll simply bolt that
flange to another one, and wal-la , I'll have an inline 3 glow plug heating
device for my coolant, and I plan to put that in my heater circuit, right in
the hoses somewhere.
A tdi has a 120 amp alternator to cover this current draw. A waterboxer
has a 90 amp alternator, maybe I'll just run 2 glow plugs, or monitor
voltage levels .....but that should give great heat in minutes. You could
also consider putting this in your main circuit to keep the engine up to
temp.
Now if I just had time I'd get right on the glow plug system for my
personal vanagon !
Scott
www.turbovans.com
-----Original Message-----
From: Geza Polony [mailto:gezapolony@SBCGLOBAL.NET]
Sent: Thursday, December 27, 2007 12:06 PM
To: VANAGON@GERRY.VANAGON.COM; Scott Daniel
Subject: Re: Overcooling Hypothesis--Long
Scott,
You wrote: "You could also try blocking off radiator air inlet, like all
big trucks do
in the winter. You should have your heater hoses insulated, and run the
warmest thermostat you can find."
This is what I thought would do the trick at the beginning. In fact, the
problem is not one of overcooling (if it were, a closed thermostat would
immediately solve the problem) but of UNDERheating. That's what was
bothering me to begin with. If the thermostat is closed, it shouldn't matter
what happens with the radiator, the coolant lines, the heater cores, etc. as
there is no circulation anyway. Testing the tstat and finding it good left
me stymied. Again, this is a problem with lack of heat generation, not
overcooling. You could pour the coolant out on the ground and it would still
run cold (because in fact, it's not "running" in these condtions, just
sucking in cold air.)
Putting a manual bypass on the idle switch should solve this problem. But
I'm wondering what that would do in other conditions, especially when you
really are idling. Wouldn't it produce an abnormally high/fluctuating idle?
Also, it seems like when you bypassed the idle/decel switch in times of
ordinary, ie. not freezing weather, deceleration, you would get worse gas
mileage.
Any 2.1-ers out there with this problem? I'm wondering if VW realized there
was a design error and corrected it in later versions.
Geza
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