The psi of the exhaust would exceed the psi in the scoop's intake, such
that air would be coming OUT of the intake, not IN. In other words,
you would only have created another outlet for the exhaust gasses.
If you're interested, here is a great technical article by Dave Vizard
from the May Popular Hot Rodding:
Among other things, the article explains that in an optimized (i.e.,
race) engine, there are actually five cycles, not four. The "fifth"
cycle occurs during valve overlap, when negative pressure waves (i.e.,
vacuum) travels up from the header collector to the exhaust port and
helps draw the fuel/air mixture into the intake port.