I flew two flights today for a total of 4 1/2 hrs..Immediately after the first flight in which my oil temp gauge was reading in the high 160s, I landed, shut down (after minimal taxiing) and read my oil sump temp at 153 deg; about 7 deg less than the gauge reading at shutdown, I used a borrowed laser infrared thermometer. On the return flight my gauge read in the low 170s; the ambient had increased from 75 to 80 deg. Taxi after landing was much longer, and the oil had cooled to high 150s, prior to sump measurement at 150 deg. Conclusions: Actually I'm not sure, but think my gauge is reading accurately (and a boil test of the bulb will probably confirm this). I think the 7 deg "drop" in temp from the gauge to the oil sump could be attributable to the cooling effect of the painted metal sump itself. I also think I will consider reducing cooling air flow from baffles when winter months arrive, hopefully to keep the oil at a minimum of 165-170 deg.
Semper Fi
