986.2 and 987.1 IMS Bearing Question

I have a 2007 Porsche Cayman with 45k miles, I have knocking and brass/bronze metal shavings in the oil and filter, most likely bad journal bearing, so I am looking to swap out with a used engine. Does the IMS have a greater tendency to fail on less frequently driven vehicles? Do I want the M96 engine that can have the IMS fail (but be replaced) or the M97 engine that has the larger bearings (but if something happens to it, isn't replaceable)? I am able to source a 2006 2.7L Porsche Boxster engine that is an M96 ...I know some of these engines actually HAVE the larger IMS bearings...does anyone know how I could find out which IMS it has without taking off the transmission? I know I could potentially use a borescope to look through the opening just under the clutch...seems a bit sketchy to measure 22mm (this is the measurement of the larger IMS bolt...what is the size of the smaller IMS bearing bolt?) from that situation. Is there some way to derive this information from the VIN? Maybe the lawsuit VIN#'s? Thanks!

I would suggest that you start your search by checking out jake Raby's Flat6Innovations series of videos on bore scoring, IMS , and oil starvation issues of the #6 rod bearing with the M96 and M97 engines. He gives the full linage of small single bearings, double bearings and large single bearing ( cayman ).

Yes, I am in discussion with Jake I just sent him an email. I know the 3.4L engine has issues with cylinder bore scoring on the #6 cylinder. I am just looking to do a simple 2.7L to 2.7L swap, just trying to figure out if I should go with the M96 or M97 engine and/or the smaller or larger IMS bearing .

Get the larger single row bearing that a M97 engine has. Much better lifetime average.

So it turns out that my current "failed" engine is an M97... Has anyone used the, "EPS IMS Bearing Upgrade"? Looks like a solution for BOTH the M96 & M97 engines... https://www.europeanpartssolution.com/ims-bearing-upgrade-kit I think I might buy an M96 and easily remove the old bearing and replace it with one of these. 5 year warranty!

Why? Did your IMS bearing fail. No. It was the rod bearing. Talking about the IMS bearing on your M97 engine , take it apart and have someone examine it. 99% assured it did not fail. Your engine scared the rod bearings due to overheating of the oil lubricating through the rear main bearing on its way to the #6 rod bearing. Happens frequently in non prepared cars during the later part of the 30 minute run. Rod bearing scaring is also known to occur with oil starvation in part due to the use of R rated tires . These tires also help keep the engine oil trapped in the head at the opposite end from the head return pump. This oil is turned into froth due to the valve springs mixing air into the oil. As this mixture makes its way back to the sump, after 15 minutes of this action, the engine oil starts to become diluted with a mixture of heated air and oil. It's not enough pressure reduction to cause the pressure to drop to 20 psi, but enough to reduce its effectiveness. You can get a updated IMS bearing that has direct oil injected to the bearing. Good to know. But, during the later part of the track run your #6 rod bearing fails again due to oil overheating reducing the oil's film strength keeping the metal parts (rod bearing and crankshaft) apart. So the addition of a 3rd radiator to cool the water and a larger engine oil/water heat exchanger and a deeper sump, X51 baffles and a windage plate to keep the oil surrounding the oil feed pick up. Also part of this issue is due to the use of light weight oil. LN recommends XP9 10W-40 oil for the M97 engines when we track them. Specially formulated to not foam in the heads, yet keeps the viscosity high enough when heated to above 300 degrees to maintain film strength in that critical rod bearing. This info can be found on the LN web site and Charles explained this issue on the LN facebook page as well.

My current M97 rear main seal is leaking like a sieve.

Any local repair shop would be able to fix that seal, especially if you were to change your clutch/bearing etc. The transaxle needs to come off. I know as today, my clutch is being replaced and a new Wavetrac LSD is being installed as well. Shop is also looking at the shifter wheel to assure its action is not sloppy. Shop is also looking at the main seal and IMS bearing plate to see if any oil is seeping out of either of those areas. Once those are looked at, new clutch plate, bearing and LSD is installed, then back together for another 50k miles of useage. The clutch was a preventive measure.