Update. Plane left Madison, WI with 7qts of oil in the sump, after landing in Champaign, Ill the plane had 3 qts. So, it lost 4qts of oil in 1:15. According to my partner, the engine continued to run smooth and he felt no power loss. After landing the shop on field cut the filter, and found it to be clean. They checked the screen, and found pieces of ring in the screen. Based on #3 being low on EGT, they pulled #3 , and this is what the piston and ring pieces looked like.