Okay fellas, I have a tire! I will try to show how I did this. First step-I bedded the master part 1/2" deep in modeling clay. I put 4-3/8" steel balls in the corners and sprayed in the release wax.
Then I poured the top half of the mold-
After this cured for 16 hrs. I turned it over and removed the modeling clay and the steel balls and put the stems on for fill holes and air vents and sprayed the release wax on this surface.
I then poured the other half of the mold.