Posted for randy snarr <randylsnarr@yahoo.com>:

 All,
 Thanks for the good suggestions on the oil cooler.
 I flew again today and my oil temps are at 208 F flying in 35 f air.
 They will be 215 or 220 this summer.
 I will try a few solutions that do not need to cut the cowl. I will most
likely make a duct to carry the exhaust air from the oil cooler down to the
lower aft part of the cowl. I have also heard that the aft vertical edge of
the naca opening should be shaped like an air foil. Mine is flat and fairly
sharp. The easiest way to test will to be construct a piece to give it a
little airfoil made from balsa or foam taped in place and flight tested. If
that does not work, I will make a duct from the cooler to the low pressure
area on the bottom of the cowl and lastly would be a small lip on the bottom
of the cowl aft.
 every producton airplane I have seen with an opening on the bottom of the
cowl has 45 deg lip to create a low pressure area. I should have done that
before I painted....
 
 
 I will post my findings when I get them.
 
 Randy Snarr
 N694RS