I've been following this topic with interest....  Depending
on the cost, a generic water pump _may_ be a good idea.

advantage(s):

        water flow across the engine jacket, thru the radiator
        would be independent of engine speed -- same issue as
        electric vs. pulley-operated cooling fans (and one _less_
        belt).

        one could potentially get rid of the thermostat -- just
        have a few different speeds in the pump

        probably cheaper than the approx. $200 VW of A charged
        me when the last water pump broke down.

        can be placed anywhere in the circuit, making replacement
        possibly easier (the VW dealer also charged me $200 for
        labor -- grrrrr).

        can be cascaded  for hotter climates 

a couple of considerations, though:

1) what makes us think it's going be longer lived than the $200.00 made-of-gold
   pulley-driven waterpump?

2) are we going to start going through alternators now that we've added the load
   of a water pump to our electrical system?  (Need to know the flow
requirements
    to make a back-of-the-envelope calculation). -- Maybe they should start
building
    water-cooled alternators :-)

Cetin

One interesting thing: the '82 diesel westy is the one with the least
engine heat problems among our 3 VW bricks -- how come??? (It has been
suggested that ours might have a stuck thermostat -- oh well)...

      At 04:20 PM 6/24/96 -0500, you wrote:
>  I've recently leaned that both Ford and Chevy have produced 12 volt 
>motor driven water pump equiped vehicles, so the duty cycle should be 
>just what water cooled VW boxes need, and the volume is supposed to be 
>considerably higher.  Speed shops sell a "universal" equivelant.

Interesting.  How much do they want for one?

>  So, if we added a powerful 12 volt water pump, should we trigger it with 
>an engine heat sensor and use a check valve to avoid having it drive some 
>of its flow backward through the inadequate stock VW pump at idle?  Then 
>again, perhaps we could just remove the stock pump while saving the 
>plumbing access.  Thoughts?  I can hardly wait to hear that I shouldn't 

You'd need to bypass the stock water pump -- it would be getting in the way
of the water flow (unlike the cascaded electrical waterpumps, the mechanical
pump would dictate the flow and really mess things up -- the electrical pumps
would actually help each  other as long as they are 'almost' identical)

You'd have to run the pump continuously -- just let the mechanical thermostat
& the fan thermostat regulate the flow path & temps. (if you quit running
the pump continuously you risk creating hot spots).

Cetin Seren				Direct:	412-635-3479
Software Development Engineer         	Main:	412-772-6600
Outbound Technology Group		fax:	412-635-3350
FORE Systems, Inc.			email:  cseren@fore.com	
Research Park, 5800 Corporate Drive	URL:	http://www.fore.com
Pittsburgh, PA 15237-5829