Cylinder sleeves

[MNBoxster]

Originally Posted by MikenOH

Where did you get the 3600 figure for the number of sleeved blocks?

I ask since the window on these blocks is usually noted as 10-98 through 2-99. If they were building roughly 1900 cars/month and the problem with the supplier ran 4-5 months, the number would seem to be a lot higher. Or were they building cars with both good quality blocks and sleeved blocks at the same time?

Hi,

On inquiring, I was told this at a PCA Tech session by a Guest Speaker from Porsche AG.

And yes, it was only a portion of the blocks produced during this period which failed Quality Inspection.

Because the M96 Block was shared by the 996 also, (it is now shared by the 997, 987 and Cayman), Porsche made the decision to use only A grade blocks for the 996 (makes sense since they're double the cost) and to repair the reject blocks (by post-cast machining and inserting sleeves) for the Boxster. He further said that there were no records as to how many of these stayed in Stuttgart and how many were shipped to Valmet in Uusikaupunki, though some were shipped to each. Hope this helps...

Happy Motoring!... Jim'99

[MikenOH]

Quote:
"Because the M96 Block was shared by the 996 also, (it is now shared by the 997, 987 and Cayman), Porsche made the decision to use only A grade blocks for the 996 (makes sense since they're double the cost) and to repair the reject blocks (by post-cast machining and inserting sleeves) for the Boxster. He further said that there were no records as to how many of these stayed in Stuttgart and how many were shipped to Valmet in Uusikaupunki, though some were shipped to each. Hope this helps...:

originally posted by MNBoxster


So, they knew they didn't want to put those blocks in a 3.4L 996 which sold for roughly $75K+ but they were OK for the 2.5L 986 selling for $45K+. Wonder if they thought 996 owners would be more outraged at Porsche using reject blocks in a 996 than 986 owners might be or if the additional HP and torque of the 3.4L motor would be more prone to make those motors fail?

Either way it stinks. If it was a good idea and they really didn't expect a reliability problem, it should have worked in either car. If they thought there might be a reliability issue, then it shouldn't have been done.

The comment about the lack of records on where they went seems like a odd. As anal as Germans can be at times on details--I'm married to one--and the fact that each of these motors required a lot more labor in production than the unsleeved block, you would think they'd know exactly which motor was sleeved, which wasn't and where it went.
Then again, maybe they didn't want to know.....

Interesting story though; thanks for sharing it.

[Brucelee]

I found the lack of records hard to believe also.

[MNBoxster]

Originally Posted by MikenOH

Quote:
"...Then again, maybe they didn't want to know...

Hi,

Exactly...

Happy Motoring!... Jim'99