Does anyone have a real answer why hemis eat lifters/cams? I do realize the needle bearings go but is it a material or production defect? I have done some searching and have come up with earlier production of the mds lifters doing this but there is no definitive answer as far as specific part numbers go (at least I didn't find anything). From what I can tell all of the new mds hemis use the same lifter and they have superseded a fair amount of previous lifter models.
I think it has to do with the VVT cam lobes,
53022064BD (cars) duration intake 258* exhaust 288* / lift intake .472 exhaust .461
53022314AD (trucks)duration intake/exhaust 290* / lift intake .472 exhaust .460Automatic 5.7
186/208 (4 lobes are actually 205 on the exhaust for MDS)
499/493 (4 lobes have 486 lift on the exhaust for MDS)
115LSA
103ICL
Not sure why but I think when the oil is cut to the MDS lifters there not enough residual oil to keep the roller lubed and the aggressive nature of the MDS lobe puts more stress on the roller....so it's a design flaw in my opinion...…..Lifters don't fail on the Non VVT cams.
