Over the 7 years I was building my plane I would hear how hot the 320/360's would run and I was told that mine would be the same way do to the tight cowling.  I found this hard to believe and I would not accept this.  Here is how I resolved this problem;

1.  My  oil temps ran 250+ (red line) until I did the following--I put a naca scoop in the center of my top cowling with a 3 inch flex tube to the oil cooler and closed the 3 inch hole behind # 3 cylinder.  My temps now are 185 to 190.

2.  Cylinder temps were-- # 2  465+,   # 3  445+,   # 1  425+ and  # 4   415+
What I did to correct this was---when I closed the 3 inch hole at # 3 cylinder I replaced all rubber baffling making the with of the rubber that bends over at least 3 inches bending over and one solid length around the engine on three sides--the original rubber was about 2 inches long with slits cut every 3 to 4 inches.  This lowered the temps about 10 degrees.  Next I took the servo off and had the fuel flow on take off increased--each cylinder came down 25 to 30 degrees.  Two additional times I had the servo fuel flow increased on take off--My temps now never exceed 370to 390 degrees from sea level up to 10,000 ft on a day 85+ degrees in south Florida.

To say that I love my 360 is an under statement--I have a Superior 360 XP with fuel injection andfront ram air--I cruse at 170 knots @ 21/25.  At 25/25 I see 205 knots.  My wife loves this plane and she has not set foot in our Piper since the 40 hours were flown off--We now have 72 hours total on the plane.
Paul Hershorin
N471LA