Date: Mon, 25 Nov 2002 01:09:21 -0500
Reply-To: Karl M <thewestyman@MINDSPRING.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Karl M <thewestyman@MINDSPRING.COM>
Subject: Re: Attention TDI Gurus! What is hotter, oil or compressed air?
Content-Type: text/plain; charset="iso-8859-1"
David,
My findings are that the stock oil-water oil cooler is just fine unless you
are doing heavy towing. Using this cooler in my TD, oil temps rarely pass
120C. The Mazda oil cooler needs more airflow than it will see in your
planned location. I think it needs higher-pressure air, like is available at
the nose of the van. I tried a Mazda cooler in rear locations and oil temps
soared, even in winter, to near 140 C. The intercooler also needs better
airflow than will be had in the engine compartment. Think about an
air-to-water intercooler system. VW, Subaru, Audi and others are now using
those. Good luck in your project.
Karl Mullendore
Westy Ventures
1987 Westfalia Syncro 1.9TD
----- Original Message -----
> I am doing the final - on paper design of my ALH TDI installation that
will
> be going into my Syncro DoKa over the winter. From what I have heard from
a
> lot of TD and TDI owners and from my personal experience with a 1.9L AAZ
> Turbo Diesel is the oil temps can get damn hot with the turbo working all
> the time.
>
> The plan is to use a bigger than stock charge air cooler (Audi 5000 or
Saab
> 900) and an external air cooled oil cooler (Mazda RX-7). With the
> experimentation that I have done with my oil cooler on my 1.9 AAZ I have
> realised there isn't a 100% optimal location for it under the van and
moving
> it up front isn't an option for me. The plan is to mount the charge air
> cooler and the oil cooler horizontally in a sandwich configuration on the
> passenger side of the engine bay about 1/2 way up the height of the
engine.
> This is to keep it away from the hot exhaust manifold on the driver side
and
> when mounting everything at 15 degrees there is lots of room on the
> passenger side. The design of the Vanagon makes it so there is air moving
> around the engine when you are driving as it did begin life as an
air-cooled
> vehicle so I feel no matter what angle I mount the coolers at it will
> provide some benefit. So, driving on cold to warm days (less than 20C)
the
> setup would do a 'better than it if wasn't there job' of cooling the
> compressed air and the engine oil. When the temp goes beyond 20C things
> will start to get a little warmer in the engine bay - especially if you
are
> moving at non-highway speeds. On most 1988 and newer VWs and Audi sedans
> there is a temperature sensor on the valve cover - this temp sensor will
> turn on the radiator fan when the engine is too hot to get air moving
> through the radiator and more importantly over the engine to cool things
> off. The plan is to use a fan (Golf radiator fan) to move air up and
> through the charge air cooler and the oil cooler when the engine gets
really
> hot. When is this? Stop and go traffic, super aggressive driving (8%
grade
> in hot weather) and after you have parked the vehicle. Temps in the back
of
> the van get REALLY hot after you have parked it. The fan will have two
> functions - it will draw air up through the coolers and circulate it over
> the engine to help cool it off.
>
> So in making the cooler sandwich, which one should be on top - the air or
> oil cooler?
>
> David Marshall
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