I'd say forget the intermittent firing mode.  For the same power it would likely result in just as much,+ or - , as reduced throttle; and shake the hell out of everything connected to the engine.  As I understand it, the Cadillac mode is an attempt to improve mileage at low load; maybe 15 - 20% power or less.

 

If you are going to try to design against coolant loss; you may just as well try to design against loss of oil, about the same probability of occurrence.

 

As far as scoops are concerned, a NACA scoop may work fine if everything else is right, but will never have the pressure recovery efficiency of a well designed ram scoop.

 

That'll be 2 cents, please J

 

Al