Perry Mick wrote:

I got the modified oil cooler installed. I flew Monday morning, but could
only go to 1500 feet because of low overcast. Oil temp only reached 182. It
was a cool day, but this is about 10 to 20 degrees cooler than normal. After
having oil temp problems for the last 4 years I do not attribute the
improvement to the new mounting method, but to the 86 oil cooler I was able
to use. I'm convinced there is something different on the internals of the
82 vs. 86 oil coolers, and the 86 is more effective. The ports on the 86 are
odd, so if they are not convenient in some installations I would recommend
plugging them, drilling a hole in the tank on the convenient side, and
welding on a 1/2" NPT aluminum half-coupler available from McMaster Carr. I
was going to do this a year or so ago, but didn't want to go through all the
work without knowing for sure there was an internal difference. The outside
dimensions and appearance of the coolers is the same except for the port
location. The 82 has 8mm ports same as the front of the engine, and the 86
has 10mm ports same as the rear of the engine.
I couldn't fly yesterday morning or this morning because of fog, but will do
one more test flight to verify it is cooling well. Then I want to relocate
the oil cooler so the right side of it adjoins the left side of the lower
cowl, and the inlet will be more like an armpit. And I will close up the big
hole in the upper cowl that is no longer required.

Perry

Perry, please measure the pressures on the face in four equal divisions
along the oil cooler for me. Should be easy with your new digital camera.
Unfortunately you made two major changes at the same time destroying the science :) 

I am sure the back side is OK but you never know so if you don't mind
put some pressure taps back there as well.

Are you using the foam ramp or just the blunt end of the cooler?
I think you could come straight forward with the ramp instead of
tilting it down like that. Should cut the drag slightly. 

Also think about adding a boundary layer air bleed when you rearrange it.

Check and see if this configuration has affected your top speed.

If you remove the fittings and look inside that 82 cooler you should see
some turbulators in the tubes. If not that may be its problem.
That is the only thing I can think of that would make such a major
change in its cooling ability.

Paul Lamar
 
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