Date:         Wed, 15 May 1996 04:22:58 -0700
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         jwakefield@4dmg.net (john wakefield)
Subject:      Re: Wasserboxer cooling (was:Re: aftermarket instrumentation)

Jim Davis wrote (in quotes):
  "BTW do you own one of these motors and have first hand experience with 
it?"  I've owned two spark ignition versions and currently own three of 
the diesel versions.

  "I don't recall any cooling problems on the list that were tracked to 
"design flaw".  If it were a design flaw, it would be showing itself in 
my vehicle as well - it is not."   Safety margin required to accomodate 
slightly out of spec systems may not be required on yours, and your 
experience may simply be a testimony to you and your atypical vigilance 
rather than to the bus cooling system design.  What differences did VW 
include in later systems like your 87 Syncro compared to those before? 

  "These are all problems that can and do affect all water cooled 
engines.   .   .   Can you site any examples to the contrary?"
Yes, I think any comparison with the great mass of alternative brand 
vehicles would easily reveal that water cooled Vanagons have a 
disproportionately larger share of heat related problems than others.  Do 
you honestly think that if this were a Toyota or Honda list that engine 
heat concerns would receive much attention?  I don't.  VW bus failure to 
comply with contemporary world standards in this specific area is 
reflected in that difference.  Already two respondents to your note 
indicated that they had to stop and let their systems cool during cross 
country mountain climbing.  Besides antiques and design defects, what 
other class of vehicles typically stopped on those inclines?  By 
contempary standards, if a typical driver has to nurse-maid their VW bus 
along while watching to make sure the heat rejection system doesn't get 
beyond prudent temperatures, that's a clear indication that something's 
different form the norm.

  Then you cite your recent personal experience with your fine running 
machine.  I'm glad that you have your machine running so well.  You say 
"I expect that you'll say - "Ahhh,  that's only coolant temperature."  
No, as a matter of fact, your experience described with your machine 
sounds like what all Toyota or Mazda van owners probably expect.  I think 
if your experience were shared by almost all other owners of VW water 
cooled buses, just as with the other brands, this thread would not exist. 
Instead, I'll bet there are lots of water cooled Vanagon and Westie 
owners on this list whose machines couldn't perform as you described 
yours doing.

  Jim said "While it would be a bad idea to measure coolant temperature 
at the radiator for instrumentation purposes, turning on & off the 
radiator fans with a temperature switch here works just as well as a 
switch at the engine."  Really!  So the '83 diesel Westie imprudently 
left idling in the hot sun for 20 minutes which never alerted me to the 
fact that it was heating by turning on either the low or high speed fan 
circuit, but which on returning to the driver's seat was found to have 
the heat meter at full scale and the light flashing must have had 
defective radiatior mounted fan control thermostat switches, right?  
Wrong, I tested both and reported the test a while back in Boiling 
Aligators in Florida (having used aligator clip test leads in the water 
on the stove).  The water in the radiator never got hot enough to call 
for the low temp switch to come on at 200 to 208 degrees F. specified in 
Bentley.  An RV at a camp site should be able to set their idle high to 
execute a parked recharge to its battery or batteries, and with an idling 
fuel consumption of .13 gallon per hour, the 1.6 VW diesel Westie should 
be particularly ideally suited for this.  At a pint an hour, that's a 
pretty trivial heat load, yet it can't handle it.  If you call this 
failure to even switch on the low speed radiator fan circuit adequate 
design, then I'll accept that you and I have different standards and let 
it go at that.  Yes it's been front elevated and properly burped.  I 
guess the changes I'm doing are making it even more adequately able to 
reject heat.  I've seen a VW diesel motor used in a custom RV generator 
that runs for vary long periods at low speed but is connected to the big 
bus motor's cooling system, and it was a beautifully running system in 
all respects.  They said it used so little fuel it wasn't funny and gave 
no trouble.
  
  "All VW needed to do is determine the proper engine coolant operating
temperature, and choose a radiator mounted switch with an appropriately 
lower  setpoint to account for the temperature loss in the hoses between 
the engine and the radiator.  I believe that they have done this,"   
Again we disagree.  I'd agree if the water pump/coolant system flow curve 
over the motor's operating range maintained a narrow range between the 
block temperature and the radiator, but that's just wishful thinking.

  "By what calculations have you determined that the coolant lines are
"undersized - for - their - length" ?"  Direct observation of differences 
obviates the need for calculations.  Just as with the famous story about 
one of Edison's hired engineeers who he discovered deep in calculations 
to determine the volume of a flask, Edison took the flask and filled it 
with fluid from a calibrated cylinder and made a direct observation.  
Similarly, the diesel Rabbit running the same motor but having short 
lines performs very differently when idling or pulling an outrageous 
load.  Same motor, the only reasonably explicable difference is the 
different cooling system. 
  I'm not going to accept your invitation to engage in personal 
comparisons, but in my defence, you described yourself as a kid around 
the early 70's when I was working on my post graduate degrees.  Could we 
stay on the topic of how to make all water cooled VW busses handle heat 
as well as yours?

	John Wakefield