how much heat is to much for the fuse ,i have a bvm t-33 with an open install the p-80 is set about 1 inch from the bell mouth of the pipe which is a bvm or tams not sure double wall starts about 6 inches after the bell mouth on ground run the fuse gets to about 130 to 140 degrees after about 3-4 minutes of run i think the fuse will cool down in flight just wondering if this it to much heat for repeated runs any help thanks