Posted for "sqpilot@earthlink" <sqpilot@earthlink.net>:

  >> 1) The pumps could
  > > have differing efficiencies. That's possible but it doesn't
  > > explain the magnitude nor why auto manufacturers would persist
  > > with an inferior pump design if reverse engineering a Davies
  > > Craig pump could yield such superior results.

  I would like to take a crack at answering #1. I think the failure mode of the mechanical water pump is a soft failure----starts leaking out the weep hole, loud noise from the bearing or seal failing signals most people that something is wrong with the car. Slow loss of coolant is also another signal, especially with the idiot light telling you about low coolant levels. People have many clues before pump fails. <<<


  Valid point, Jim.  That is why I decided to go with an  installation of the EWP that comes built into the radiator, as well as installing one additional in-line EWP as a backup.  I like the redundancy. I figure that system would be less prone to failure than just one mechanical water pump, driven by GASP....V-belts.  Had many of those fail on my cars.....got that T-shirt.  Paul Conner