Thought you would enjoy seeing what I removed from my in-progress IO360B1E modification. This came from a Piper Arrow and I can only guess it was an oil separator return line to the #4 cylinder oil return line. I think Mel told me that a couple years ago. I replaced it with a standard line. That was on a certified aircraft. Maybe so, but it sure looks odd. I'm not throwing it away just yet....
http://www.mykitlog.com/users/display_log.php?user=WenEng&project=665&category=0&log=167862&row=3
http://www.mykitlog.com/users/display_log.php?user=WenEng&project=665&category=0&log=167862&row=3