Finally my days of too hot oil are behind me!  We flew on Thursday evening at 17C or 62F ... oil never exceeded 150F and in cruise was actually about 135F with the water temperature at 175F. Almost too cold, but if you add 30 degrees, to 92F the oil would be around 165F.  I will add some restrictors on the oil cooler intakes for the upcoming winter ... that I can live with.

So the second oil cooler made a big difference; unfortunately it wasn't the only thing I did. I also reduced the size of the cowl opening behind the spinner and centered it better, the original opening was 9" and offset to the low side (remember that pressure gradient diagram) so it got reduced to 6" and the lower edge lifted almost 3".  I was so glued to the gauges infront of me that I forgot to turn around and glance at the manometer - I'll bet the oil cooler differential was more than on previous flights - if true that would prove the spinner opening was over pressurizing the cowling - I'll be sure to check next time.

Jeff