To tell you the truth, I don't really know much about the porting on the engines. I got the basic concept but don't understand how improvements in performance are achieved by doing different modifications. Does blocking a boost port increase fuel efficiecy? I don't really want to do anything permenant because I am planing to convert back to glow. I have had no problems with the glow setup on this plane, I just thought I could get better power and more speed out of this engine as a diesel to begin with and now have found out other wise. The cost of diesel makes it cost prohibited for an everyday plane and although some may disagree, there is a bit more hassle with the diesel for me than with the glow since I am already set up for glow.