We're not seeing very many failures from the 067 and later IMS Bearings at all. It seems that the only time they do fail is on the track, and the reason for that is due to the bearing diameter and surface speeds.
Porsche made the bearing larger not just to increase the size of the balls and races to make a stronger bearing, but also because the larger diameter bearing had a greater surface speed and reduced loads at lower engine speeds. This is why M96 style IMSBs don't fail in high numbers on the track, but do on the street and the problem has reversed for the M97 style IMSB.
Its been two years since we had a single failure call on the M97 style IMSB that occurred on the street. We've only seen two M97 style IMSBs fail on the track in the same period of time.
Keep the oil changed every 5K/ 6 months and use something other than M1 and just drive. Nothing else is necessary with the M97 IMSB and thats been proven to us for going on 8 years now.
Quote:
|
I'd also ask how did they know the IMS was the cause. Not saying there can't be a failure but we don't see many reports on the forums.
|
True, because the IMSB is the easy thing for diagnosticians to blame everything on when they are not proficient with the internals and characteristics of these engines.
With the M97 engine I am more concerned with rod bolts and timing chains than the IMSB.