High Oil Temps

The oil temps have been creeping up the longer the flight.  Since it was rising slowly it seemed like it must be inadequate flow though the cowl.   I cut a hole just under the spinner and made a small deflector in from of the exit on the bottom.  This helped but it was still getting up to 190 after about 30 minutes.  This isn’t a problem except that it was 40 degrees out and its going to be too hot when the summer comes.  CHT are looking good about 350 and don’t get worse.  I am resisting installing an oil cooler as many similar aircraft don’t need one and it adds another point of failure with flexible oil lines etc.  I ended up making a bigger front intake and used the baffles from an ercoupe to make a good sized channel back to the oil tank.  Its still showing hotter than I would like in this weather but it stabilized at 175 on a 36 degree day.  I may open up the bottom of the cowl some more but I think I should wait to see how it does when the outside temperature comes up some.  Until this last change, the oil temp never stabilized it just kept rising the longer it flew.  Now it stops and only goes up or down a little depending on the throttle setting.