Attention: TDR Forum Junkies 
following report dated jan. 1/2000.
isb block cracking--customer issue--customers have been complaning of external coolant leaks ,which hasbeen traced to a visible crack in the block . the crack is horizontal and located on the exhaust side of the block below the large cup plugs and behind the turbo.
technical description - a similar issue was expierenced on a few industrial 0ems in the past using the pre-storm cylinder block. the crack appears horizontal on the exhaust side ,below the large cup plugs holes(between cylinders 4 and 5). at the point where the straight section of the block blends into the curve . cracks initiated on the inner wall of the block and grew to the outer wall. this was traced to a combination of stresses caused by cylinder head assenlly loads , cylinder firing pressures ,and thermal and residule stresses which are aggrevated by the specific customer application . with introduction of the storm cylinder block there has been a rise in similar block crackingin specifically the same area in light duty cycle and automotive applications. build period 1997 to present,milage 4000 plus, failure code BKCABR,p/n 3935934,
corrective action summary --- a high strength version of this storm block , refered to as pattern 54. was developed to address this block cracking . the area under the large cup plugs have been redesigned to incorporate a larger radius in the water jacket and a ribbed core to eleminate a parting line ,and the wall thickness has been increased from 5. 5 mmto 11. 0 mm. this failure mode has been replicated in a test cell using the old cylinder block . with the high strength block engineering has not been able to duplicate the failure under similar conditions . all thermal cycling tests on the redesigned block have been successful.
implemention summary---service use-- this cylinder block has been available for service use since march 29,1998 parts are in stock and ordable as new service blocks only (3935943)
the hardness of the material near the crack was 179hb, which meets the requirement of ces40001. the microstructure also met the specification with predominantly type a graphite in a pearlitic matrix. production implementation ----patteron 54 will be in production for all markets starting in april 2000. :{ :{
isb block cracking--customer issue--customers have been complaning of external coolant leaks ,which hasbeen traced to a visible crack in the block . the crack is horizontal and located on the exhaust side of the block below the large cup plugs and behind the turbo.
technical description - a similar issue was expierenced on a few industrial 0ems in the past using the pre-storm cylinder block. the crack appears horizontal on the exhaust side ,below the large cup plugs holes(between cylinders 4 and 5). at the point where the straight section of the block blends into the curve . cracks initiated on the inner wall of the block and grew to the outer wall. this was traced to a combination of stresses caused by cylinder head assenlly loads , cylinder firing pressures ,and thermal and residule stresses which are aggrevated by the specific customer application . with introduction of the storm cylinder block there has been a rise in similar block crackingin specifically the same area in light duty cycle and automotive applications. build period 1997 to present,milage 4000 plus, failure code BKCABR,p/n 3935934,
corrective action summary --- a high strength version of this storm block , refered to as pattern 54. was developed to address this block cracking . the area under the large cup plugs have been redesigned to incorporate a larger radius in the water jacket and a ribbed core to eleminate a parting line ,and the wall thickness has been increased from 5. 5 mmto 11. 0 mm. this failure mode has been replicated in a test cell using the old cylinder block . with the high strength block engineering has not been able to duplicate the failure under similar conditions . all thermal cycling tests on the redesigned block have been successful.
implemention summary---service use-- this cylinder block has been available for service use since march 29,1998 parts are in stock and ordable as new service blocks only (3935943)
the hardness of the material near the crack was 179hb, which meets the requirement of ces40001. the microstructure also met the specification with predominantly type a graphite in a pearlitic matrix. production implementation ----patteron 54 will be in production for all markets starting in april 2000. :{ :{
