Date: Sun, 24 Nov 2002 21:55:46 -0800
Reply-To: David Marshall <vanagon@VOLKSWAGEN.ORG>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: David Marshall <vanagon@VOLKSWAGEN.ORG>
Subject: Attention TDI Gurus! What is hotter, oil or compressed air?
In-Reply-To: <3DE14D19.9090603@charter.net>
Content-Type: text/plain; charset="us-ascii"
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
Fast Forward Automotive Inc.
4356 Quesnel Hixon Road
Quesnel BC Canada V2J 6Z3
http://www.fastforward.ca mailto:sales@fastforward.ca
Phone: (250) 992 7775 FAX: (250) 992 1160
- Vanagon Accessories and Engine Conversions
- Vanagon, Transporter and Iltis Sales and Importation
- European Lighting for most Volkswagen models
