Wouldn't using a 1.3 bar radiator cap or stock .9 bar be more efficient than running 0 pressure? Evans boils at 375 degrees but how hot does a rotory get? If running pressure will keep the temps down over 0 pressure, I'd rather do that than risking blowing a radiator hose or something. I don't know....what's the worse of the two evils?

 

AFAIK the purpose for running a pressurized system is to raise the boiling point for water/coolant mixture. It does nothing magical to make it run cooler. At 375 your coolant seals will be long since baked/warped and a busted coolant hose will be the least of your worries. During the summer I saw a high temp of about 105C on the PFC, (100C=220F).