GASKET - FAULT FINDING   SPLIT RICARDO PAD     FEATURES:      Edge of fire ring / Ricardo pad is burnt through with extending circumferential cracks. CAUSES:      Incorrect detonation.  GENERAL:   This type of failure is normally attributed to efficiency of burn. Many factors can be responsible and the advice and attention of a diesel specialist should be sought. (A) Faulty Injector (B) Faulty injector pump (C) Incorrect pump timing (D) Added factor of overheating   APPLIES TO DIESEL ENGINES ONLY      CIRCUMFERENTIAL SPLIT     FEATURES:      Fire ring split on the immediate inner circle. sometimes accompanied with a radial split as per photo. CAUSES:      (a) Lack of clamp. (b) Incorrect diesel detonation.  GENERAL::   (a) Lack of clamp allows the fire ring to expand and contract beyond the control clamp of the head and block. This excess movement promotes work hardening and a brittle fatigue crack results. Burn back and ingress of combustion / compression gases into neighbouring ports soon develops to engine failure. (b) Incorrect detonation on diesel engines can result in this type of failure. A combination of excess heat, extreme pressures and ultra-sonics result in this brittle fatigue crack. REMEDY:    (a) Ensure head and block faces are flat and to the correct surface finish. If required fit new stretch bolts and strictly follow tightening procedures. Cooling systems must be checked and efficiency proven. (b) Excess smoking or suspect performance of a diesel engine should be addressed by a diesel specialist.