Can you let me know the application for the W46 engine you are using? What type of fuel? Where are you located? Big end bearing problems are an issue with not only the W46 engines but with many, issue is that this engine is so big and damages are so costly that the bearing problem is exponentially used to create an uproar on faulty bearings or defects on crank shafts, added protections needed, new improved parts etc, while this might be only an operational problem. Please feel free to contact me if you need more support on this subject.