The cam failure is not caused by the MDS system, its caused by the lack of oil pressure being pumped to the top of the engine when the engine is running idle. Some hemi ticks are caused by the MDS solenoid not being strong enough to engage/disengage it, usually starts happening after 120 000km.
My theory for disabling the MDS is to save the crack exhaust bolts. My theory behind this is when the engine is running on 4 cyl, there is a heat expansion difference on the block. Constant expansion retraction must not be good for aluminium blocks and thus we see a lot of people having cracked bolts and causing another type of hemi tick. Its always the same bolts that break, the ones near the cyl that get deactivated. I've never seen the ones in the middle break. I've had mine disabled since 8000k, now at 105000k, and still running original bolts.
My theory for disabling the MDS is to save the crack exhaust bolts. My theory behind this is when the engine is running on 4 cyl, there is a heat expansion difference on the block. Constant expansion retraction must not be good for aluminium blocks and thus we see a lot of people having cracked bolts and causing another type of hemi tick. Its always the same bolts that break, the ones near the cyl that get deactivated. I've never seen the ones in the middle break. I've had mine disabled since 8000k, now at 105000k, and still running original bolts.