It might help enigne cooling, but you will likely take a big hit to highway fuel economy. Directing all that air into the engine compartment will create an enormous amount of drag at highway speeds. It could also compromise safety/handling. If there is no coresponding way for all the excess air to escpae out of the engine bay, it creates a hig pressure area under the hood. This produces lift, and reduces the weight, and traction/stability on your front end. Basically your engine bay becomes an airplane wing.
Yes, it can be done, but it's not as simple as it seems. The aerodynamics of an explorer were not designed to accomodate this. It was designed for a closed hood.
A hood scoop directly feeding the engine would be ok, because the air would never enter/build up under the hood. Also a "cowl induction" style hood is ok, because it tends to "pull" air out from under the hood. This would include hot air, which would be replaced by cooler air pulled/rammed through the radiator/grille/etc..., thereby improving engine cooling, and reducing underhood temps.
