REFLECTOR:Engine ram air

[reflector@tvbf.org]

More important than the size of the opening is the thickness of the 
lip.  No matter what you do, except at one precise speed there will be air 
spilling over the outside of the scoop OR (at low speed) air being pulled 
in from a larger area than the scoop itself.  Either way, you don't want 
air tripping on a sharp lip and becoming detached.  Give the lip a full, 
thick radius (at least as thick as your thumb).


At 06:16 PM 8/21/03 -0500, you wrote:
>Thanks Jim,
>It seems the point would be that we would need to know the velocity of
>the air moving through the 3" opening in the controller.  That should be
>calculable based on displacement and RPM's to get a volume per second.
>I thought that at cruise one would want some slight pressure for ram air
>based on the volume of air being drawn through this opening.  To much
>pressure and the air just spills over the lip of the scoop and never
>even enters the scoop.  Under non-ram arrangements this should be a
>suction but if one can obtain a slight ram pressure at a little more
>than would be sucked in at cruise of if desired at 25 squared then the
>size of the opening could be determined.  I just don't know how.  The
>pressure delivered to the scoop would depend on many factors but I would
>think the main factor would be speed of the air and the extent one can
>slow the high speed air down to get static pressure.  This may all be
>wrong or too obvious to comment on but before I sleep at night my mind
>wanders.
>Rene'
>
>PS   I built my scoop separate from the air box so it can be removed and
>the filter removed from a 3 " flange mounting for the K&N.  The approx.
>11" x 9" box has a side spring door flap to open in the case of scoop
>obstruction allowing heated air from inside the cowl but still it would
>be filtered.  No water problems and I do have a 3/16" hole in the most
>dependent point of the scoop.