What was found
I HAVE MULTIPLE CRACKED CYLINDERS BETWEEN O-320-D2J AND O-320-D3G ENGINES, THE CYLINDER IS ALL CRACKING IS IN THE SAME LOCATION NEAR THE INTAKE PORT OF THE CYLINDER. THE FAILURE TIMES HAVE BEEN BETWEEN 1087.1 SFRM, 1980.5 SFOH, 1282.1 SFRB, MOST RECENTLY I HAVE HAD 2 CRACKS ON CUSTOMER AIRCRAFT AT 600 SMOH AND 500 SFRM. THE COMMON POINT IN ALL THESE FAILURES IS ALL CYLINDERS ARE LYCOMING FACTORY CYLINDERS