Alright all you pooper-scoopers!  ;-)

Our Vanagon scoops work.  Why?  The only requirement of an body opening to
draw in air is to have lesser air pressure within that opening and greater
air pressure just outside of that opening.  Them fancy words are "pressure
differential" -- weather folk call it wind, but this one does not require
any prior consumption of beans.  If you look carefully at our scoops, they
are designed quite ingeniously.  First, the leading edge of the scoop lies
in a depression.  This causes an initial drop in air pressure causing the
air to turn in towards the body.  The rear edge of our scoop is placed just
wider than the surface of the windows -- look how the edge just below the
windows leads to the rear of the van and then turns up and behind the scoop.
This causes the air flowing next to and over the windows to ram directly
into the scoop.  Also it creates an area of higher pressure.  This
high-pressure air is sucked into the lower pressure area at the leading edge
of the scoop making the entire unit functional.  The slats in the scoop are
there to direct the air into the bottom of the air ducts lessening the
turbulence.  Next time you're outside stand in front of the Vanagon and look
down the side towards the scoops.  You'll see what all the poop is all
about.

The scoops served the air-cooled motors well, where they provided cool and
relatively dust-free air, hence their high placement on the body, for the
sealed engine compartment.  There the engine fan forced the air over the
cylinders and out the bottom.  For the H2O motors those same scoops provide
cool intake air and help to keep engine bay temperatures lower.

You want to make these even more functional?  Provide a way to increase air
pressure just outside of the scoop.  This could be accomplished by something
as simple as a piece of aluminium protruding perpendicular to the body just
behind the scoop.  Not much would be needed - maybe an addition 2cm or so.
Heck, you could experiment and use a piece of thin wood that could be jammed
between the scoop and the body.

Well, all this scoop talk and I'm missing my bed time.  Maybe I'll poop and
go to bed.

Chris.
'85 Westy.