We understand what your meant. here let us explain it for you at first. the excess material where is a injection point. liquid steel be injected by that hole. if the hole is small. it can't make sure there is much enough of material inside the parts. therefore. you will be find some little holes like blister inside when is machining. so must to make the injection hole be larger. make sure the material be run to everywhere inside the parts. but the holes is larger. the drainage material(excess material) will be more( like the sample we did). hope you understand what our meant.
So it make it be round. the Dia will be 94mm and 109mm. but there is more material for you to machining. anyway. if any better ideal. please let know