Date: Mon, 10 Sep 2012 13:56:24 -0700
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: [Diesel-Vanagon] How does coolant circuit to oil cooler work?
In-Reply-To: <1347251892.64058.YahooMailNeo@web163404.mail.gq1.yahoo.com>
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It looks to me like the idea is to prove that having the oil cooler in
the circuit keeps some coolant from getting to the radiator, thus
reducing the overall effectiveness of the engine's cooling system -
something like that.
You don't think that VW with all their experience and resources didn't
do that ?
Any idea of how many millions of VW vehciles are running around with
this same type of oil cooler on it ?
Did you meansure oil temps ?
Say you can demonstrate that lmore coolant goes through the rad if the
oil cooler cirucit is blocked off - what happens to oil temp then ?
And if you are working with an 82 diesel vangaon with a metal radiator
..used in that year only ..
and if running temps are an issue ..
and you are sure it's not due to some t-stat issue, or water pump
roational speed, or impeller type..
do consider that the metal radiators do not remove heat, especially when
old or old-ish very well at all compared to the plastic tank aluminum
fin radiators used in 1983 and up, in vangaons.
I have had my own personal 82 5 speed 1.9 TD vanagon work just fine with
a NEW stock 82 metal radiator for about 5 years...then cooling system
performance dropped off ..overheating going up 7 mile long siskiyou pass
in I-5 in Southern Oregon about half a mile from the top. 5 years on a
NEW radiator and that happened, and I had been on that same hill many
times in the same vehicle.
A new later type radiator fixed it completely.
and ..it's NOT about how much coolant flows through the oil cooler circuit.
I'm sure VW was pretty thorough about that ..
and ...really ...........with SO MANY diesel vanagons , TDI conversions
et all, running around with those oil coolers fitted...
why would it be logical to pursue this theory ...
except that perhaps someone doesn't know that thousands of vans are
running successfully this way every day ..
oil temps being the only real issue temp wise.
If you want to work on that , highish oil temps ......great.
There is not much 'wrong' really, with the stock diesel vanagon cooling
system..
other than the metal radiators don't work that well after a while..
and in the case of the later style radiators ..
all I ever see is that they don't remove heat very well eventually.
Then replacement is the correct repair.
It takes a number of years to get to that point usually of course.
oh ...about 'wrong with' stock DV cooling systems.
The two belts-with-shims belt deal works .........but a super pain to
deal with. And there is No Reason to have that system on there, other
than they must have made 5 million of those two groove sheet metal crank
pullies and had to use them up someone.
I make a perfect Single Belt Conversion system ...I am just very
busy with other things demanding my time, to promote or offer those as
a kit. If someone wants to 'sign on' to do a project like that with me...
talk to me. People would buy them, and they only have to buy it once,
and it works perfectly.
Just get your stock system working right ..including upgraded radiator ..
and there won't be any odd or weird cooling system issues.
The only two fundamentally weak areas are the obnoxious belt system
and the 82 metal radiator.
It's not even necessary to use stock DV hoses.
I did one AAZ conversion to an 85 Vanagon ..
I used one of his dead stock main waterboxer engine hoses instead on an
octopus hose ..his stock hose was a perfect 'fitter.' ..
that van has been running over two years with no thoughts about the
cooling system other than one small 'jetta hose' issue on the engine in
the beginning, which was not hard to deal with. That one I mentioned
that has a T in it going to the oil cooler.
which is 'the other' oil cooler layout, either of which works just fine.
I'd suggest starting to monitor oil temps.
Have fun !
Scott
www.turbovans.com
On 9/9/2012 9:38 PM, Poppie Jagersand wrote:
> I tried the experiment proposed in the post below. (varying the proportion of coolant between the parallel loops through radiator and oil cooler respectively)
>
> All tests were highway driving at 100km/h, 400C EGT, little wind. 10km drive in each of the three conditions.
>
> Three temps where monitored: Regular coolant temp with the regular vanagon gauge, oil cooler inlet temp with a VDO gauge, and oil cooler outlet temp with a digital thermometer (the only accurate readable of the three...).
>
> 1. Regular flows. Coolant temp at 3/4 of Vanagon gauge. Oil cooler outlet temp 97C, VDO oil inlet temp just above 220F (*)
>
>
> 2. With about 1/2 area restriction on the oil cooler inlet: No substantial change in any of the temps.
>
> 3. With the oil cooler hose almost completely clamped off: Coolant temp down a little bit to 5/8 of gage. Oil outlet temp down 3-5C to 90. VDO gauge shows just below 220F
>
>
> I can unfortunately only check temp changes, as none of the temp meters are calibrated to report correct absolute temp.
>
> The most reliable conclusion seems to be that reducing the coolant flow to the the oil cooler circuit has little harmful effect.
> The corresponding increase in flow to radiator may be a beneficial, but more detailed measurements would be needed to confirm. I might put a 4th tem sender in coolant return temp from rad.
>
> (*) Before I put in the new VDO vision gauge I tested it in a pot of boiling water. A calibrated digital thermometer shows 97C (which is correct water boiling point for the 2000ft altitude here), while the VDO showed near the 180F mark (not near the 220 as it should have. (It has no markings between 180 and 220). Therefore I suspect the VDO reads low, but the scale is non-linear and it is difficult to tell how much to add. A rough guess would be that the 220 reading would be more like 250-260F oil temp. FLAPS aftermarket oil temp gauges I've tried have been similarly inaccurate. Irritating that one cannot obtain an accurate automotive temp gauge.
>
>
> Martin (and '82 Westy 1.9TD Poppie)
>
>
>
> ________________________________
> From: Poppie Jagersand <poppie.jagersand@yahoo.ca>
> To: "Diesel-Vanagon@yahoogroups.com" <Diesel-Vanagon@yahoogroups.com>
> Sent: Saturday, September 8, 2012 1:19:56 PM
> Subject: Re: [Diesel-Vanagon] How does coolant circuit to oil cooler work?
>
> A third, easy option I'm tempted to try is to slightly vary the flow to the oil cooler in the current design. Since slightly less flow to the oil cooler loop means more flow to rad loop, that could potentially improve overall cooling capacity.
>
> To find what effect varying restrictions have I was planning to pin the inlet hose to the oil cooler varying amounts by pressing on it with an adjustable clamp.
> I'll monitor oil temps both on the inlet (normal temp sender location) and cool oil outlet to turbo, where I have placed a second sensor, to make sure cooling efficiency of the oil cooler is not compromised.
>
> If it works out, it would be easy to install a suitable size permanent flow restriction using a bushing or washer just in front of the oil cooler inlet.
>
> Martin (and Westy 1.9TD Poppie)
>
>
> [Non-text portions of this message have been removed]
>
