> Should it prove feasible, a possible advantage of the EWP that has not
> been mentioned so far is the ability to plumb two in parallel (with
> appropriate check valves) for redundancy.  Auto makers have no burning
> desire to let you switch pumps and continue driving.

Speaking of which, given the fact that these things only weigh two pounds, is there any real reason this should not be a standard practice? On a very hot day, if your cooling is not sufficient, you could simply turn the second pump on for added flow. And since it gives you a much gentler failure mode I'd be a lot more comfortable with the EWP than the mechanical in that case. Heck, we have redundancy for everything else - alternators, ignition systems, fuel pumps, etc. Why have a single water pump, when water cooling is so critical to this engine?

Of course, what would a check valve look like for a 2" radiator hose?

Regards,
Chad