Dale Rogers wrote:

Randy,

   You asked:
 
  

1.	I am building a Cozy MKIV.  It uses an NACA scoop embedded in
the belly to provide cooling air.  I am thinking of not building the
NACA scoop as I plan to use some sort of Meredith effect scoop/plenum
(ala the P-51) for cooling.  Thoughts?
    

   There are flyers who have successfully used each approach.  For example, John Slade gets adaquate cooling 
with a NACA scoop; and, the last time I looked, Perry Mick 
was using a P-51 style scoop on his Ducted Fan L-EZ.

Dale R.
COZY MkIV-R13BNA #1254
Ch's 4, 5, & 23
  

I still have the NACA. I have no cooling problems because the ducted fan assists airflow through the rad. About a year ago I lowered the inlet lip about 1", increasing inlet area to the rad, and making sort of a scoop out of the NACA. But it had no effect. My rad cooling is sufficient, but it's limitation is probably my small rad size and not airflow.
Eventually I will probably grind all that NACA stuff off the belly and use the original Long-EZ P-51-type scoop. My LEZ fuselage tub was fabricated to the original design, the NACA was added on later, unlike the Cozy, which I think has the NACA designed into the fuselage tub.

Perry