Good posts Charlie. Just a random thought, do you think that it would be best of the water injection system self drained the lines at shut down or however they were evacuated to keep liquid out of the motor when not running?
I think Dzacc was our local guy that ended up with a motor full of water from his system back when.
we had that happen as well years ago on a Snow kit with a local guy...they (Snow) had the solenoid valves as an option, LOL...
definitely use normally closed solenoid valves (on any line prior to a nozzle)..so that hot sun + water tank doesn't equal .5-1psi of positive tank pressure doesn't push water into the engine while sitting.
The kit we put together with CoolingMist has 2 solenoid valves.