Replacement engine questions

I have a 99 that had a warranty replacement engine installed in July of 2001 by a dealer. The new engine number is M660166X16044. I am wondering whether the engine would have a single or double row IMS bearing, and whether it will have the thicker cylinder walls. The last 5 digits of the engine number fall after the number that Wayne indicates in his 996 101 projects book as being the cutoff point. That suggests a single row IMS. However the install date suggests that the replacement is likely to be from an earlier double row core. Or do the replacement engines have a separate numbering system? When Porsche set up the engine repair facility, did they incorporate any improved procedures and parts into the repaired engines that were then used for warranty replacements? Is there any info out there on the engines that came out of the repair factory? Thanks in advance for any info that you have. Happy New Year!!!

During the lawsuit against Porsche concerning the IMS issues - Porsche was UNABLE to give a clear stop/start as to the exact serial numbers that received the single row bearing after using the double. It is *believed* by many that the single row began at some point in 2000 but even Porsche does not have the documentation on which engine number or chassis number this occurred on so I fail to see how Wayne has some sort of definitive serial number line in the sand where the factory does not. As to your reman engine: I have heard that Porsche changed out parts required on these engines that were judged as suspect or defective. Engines that came into them with major issues such as cly bore score or holes in them etc were scrapped if the labor hours/parts list exceeded a set $. The engines used were engines where the labor hours at the dealership level would be cost prohibited due to the local level inexperience and possibility of making errors but most of these engines did not have catastrophic failure modes. The 'belief' that reman's got you a far 'superior' engine is pretty much urban myth most are finding out years later. Jake at LN has rebuilt engines that were reman and has reported seeing mostly period spec parts. The engine reman process HAD to cost less then giving the client a new engine off the line. That was the whole basis for the process or else you would have received a new engine with a different year build. Remember Porsche was trying to get their clients through the warranty period with as little expenditure as they could - not give them a zero reset on the length of warranty. Your engine has the exact same technology as any other 99 engine and where it was *practical* - Porsche installed the latest part they had in the supply chain. If there was a better water pump in production in 2003 but the water pump was determined to be fine in your 99 engine, then they left it alone. They only selected engines for the reman program based upon the service data they had from the dealers and their inspection program. The same thing has occurred during the GT 3 engine issue. Many owners were dismayed to find out they were not getting 'brand new engines' but reman's. Now there is a lawsuit over this program. The only way to know what type of IMS bearing you have is to inspect the flange next time you do the clutch. The double row bearing from Porsche's disclosure during the lawsuit has a > 1% failure rate. The highest rate was post 2004 with an 8% rate. Your serial number does not show the 'AT' that we are used to seeing which stands for 'AUS TAUSCH' or exchange in German. Porsche gave a two year warranty on these engines. What evidence do you have that this engine is a replacement?

Thank you torontoworker-that helps a lot. I have attached the invoice on the engine replacement-they call the new engine an "exchange engine" whatever that means. That makes me think that this was a factory warranty job. The replacement engine's number is in the usual place on the bottom of the case-but it is very lightly inscribed with a hand held tool, not stamped like other engines that I have seen. Can you point me toward any published articles or reading on this subject? Thanks again!