That's very interesting, Thomas.  I too recall seeing in several places reference to
exit area being some multiple of the inlet with the ratios varying from
1.2 -1.7.
There certainly could be some kind of phenomena I have not hear of or
read about, but seems strange you would ever have your intake area more than
the exit area.  But assuming no error then it would appear to me that
external diffusion is taking place.

 What  that  indicates to me is that the exit area (what ever size
it was) provides adequate airflow for cooling flow through the engine
compartment.(assumption is the engine did not get cooked).  Enough air mass
HAD to leave the cowling sufficient to carry away the necessary BTUs of
heat.  That said, then if the inlets were 135% larger than the exit area,
then air HAD to be spilling around the inlet or area of external diffusion.
The air molecules in this part of the airflow (external to the cowl) then
contributed NOTHING to carrying away heat from the engine, but do add to drag - that left only
the air that past through the core (or over the cooling fins of the cylinder
head) to provide for cooling. Since this air has now been heated and expands
to a larger volume, you traditionally need a larger exit area to accommodate
this large volume of heated air.   That air must leave the engine
compartment via the exit. So I just am unable to come up with a scenario
where having an inlet larger than the exit area would be beneficial.

Having said that, it did just trigger a thought about why this might be tried and
how it might be made to work.
.
We do know that for air exiting the cowl to provide minimum drag it ideally
should be accelerated back to the airstream velocity before intermixing.  We
can theoretically do this by taking the larger volume of heat air and designing an exit area
which would  accelerate the air molecules increasing the velocity of the
exiting air and reducing drag.  However, to accelerate the cowl air velocity to anything really meaningful,
would require added energy.  This leads me to believe that  perhaps an
exhaust augmentation system could be used to provide increased velocity to the exiting air using the energy in
the exhaust flow.  If the exiting airflow velocity is increased over than normally associated with exiting air, then more air of course could flow through a smaller opening, this would perhaps permit one to have a smaller exit area than intake area and still
get good cooling and low cooling drag.

So with an exhaust augmentation system "helping" the air in the cowl to exit
quicker and at a higher velocity, I can see where a smaller exit area might indeed be workable.
But, without an exhaust augmentation system, I just don't see how a smaller exit area would be beneficial.

Any mention of exhaust augmentation??

Well that my $0.02 worth on the topic

Ed

Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com> Hi Steve,