The KJ is KJ-ZEM I believe the M stands for Miller Cycle. This is the strangest motor you will ever read about. The intake valve stays open during the compression stroke...The Supercharger does the compression work. Then the intake valve closes just before fuel & spark. I am currently rebuilding one. It would be a fun project to stuff it into my Mx-3 but I will probably just put it back into the Millenia and sell it.