от Joreto » 04 Юни 2008, 09:57
Ровейки се из волво форумите намерих доста интересна информация която може да обясни причината за счупване на виелата на 1-ви цилиндър при мен . Информацията е за volvo B230 мотор но при МБ аксиалния лагер също се намира по средата на коляновия вал .
The early B230's connecting rods are the biggest concern of the two, and often fail catastrophically when the boost is cranked up where serious
detonation begins to occur. The crankshaft's design is a contributing factor to this problem -- the axial bearing is located in the center of the crankshaft, and the "undersized" main bearings contribute to some unwanted flexing. It is pretty clear that crankshaft flex is a contributing factor to connecting rod failures on the early B230s because when a connecting rod goes, it is almost always # 1 that breaks. If connecting rod weakness were the sole cause of the failures, then we would expect to see a random distribution of failures between rods 1 through 4. But we don't, which points to contributing factors, which in this case is some degree of localized flexing of the crank in the vicinity of the number 1 connecting rod. This problem can be ameliorated to a significant degree by replacing the connecting rods with those for a 1989 or later motor (see the comments on these rods below), and by balancing the rods with all other reciprocating components at the time of their replacement.