I took the Cozy up this morning for the 2nd flight on the new cooling system. The OAT was 3 or 4 degrees warmer than the first flight, as it was 79 F when I took off.
This time, I turned the cooling fan on while I was taxiing out to the runway. After the taxi and pre-flight checks, the oil was 135 F and the coolant was still reading pretty low. Maybe 115 to 120 or so. It is a little hard to read the analog gauge down on the low end of the scale.
I took off and climbed up to about 1300 FT AGL, at which time I pulled the throttle back some and continued a cruise climb. The coolant was showing about 190F, and I didn't think to check the oil temperature. Oil temperature has not been my issue. It has always been the coolant. The coolant temperature did still increase a little, even at the reduced power, but just up to 200 F. I was close to a low cloud layer at about 1800 AGL, so I throttle back some more and dropped the nose to level flight. I also turned off the cooling fan to see what the temperature would do on it's own. The temperature steadily dropped to about 180 degrees within just a few minutes, and then stabilized there.
I cruised around for a little while, flew over my house and circled it once, and then headed back to the airport. With the low cloud layer that had moved in, I really didn't know if it was going to clear out or get thicker, so I flew the 5 minutes back to the airport, and made a normal landing. As I was ready to throttle back to descend about 800 feet to pattern altitude, and quick check of the coolant temperature showed about 160 degrees. Not bad at all, although I was probably flying at about 60% power. Still, it would have not been nearly that low before the new cooling system.
Once I landed and was clearing the runway, I checked the temperatures again, and the coolant was less then 140 degrees after the glide in to land. Since I planned to wash the plane, and sometimes it starts hard after getting heat soaked sitting after a run, I turned on the cooling fan while a taxied over to the where the wash area is. After washing the plane, it started up pretty easily, so I guess that worked out also.
So far so good. I like what I see so far on the radiator, and the cooling fan definitely gives me a lot more options.
Steve Brooks
Cozy N75CZ
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