What was found
#4 CYLINDER WAS READING HOT CHT TEMPS ON INSPECTION FOUND A CRACK RUNNING AROUND CYLINDER HEAD BETWEEN HEAD FIN 6 AND 7 FROM BOTTOM OF CYL HEAD. CRACK WAS ABOUT 6IN LONG AND COULDN'T BE SEEN FROM INSIDE OF CYLINDER. THIS TYPE OF CRACKING COULD HAVE CAUSED HEAD SEPARATION AND NOT A PERMISSIBLE CRACK THAT WAS SIMPLY OVERLOOKED. NO OBVIOUS NEGLIGENCE WAS NOTICED ON CYLINDER WHICH LEADS ME TO BELIEVE IT WAS DUE TO IMPROPER MANUFACTURE OR MATERIALS.