I'm working on a 2 stroke engine cylinder and I'm trying to model it with regards to the casting houses requirement for no undercuts for the mold. I'm wondering how I can fill in the attached undercut on the transfer port. I need it to basically fill in exactly where the red is from the undercut analysis. I could do it if I could somehow project the profile of the tangent edge of the port as seen in the second picture. I could then extrude a surface across and fill it in. Any other thoughts?