IMS - Dual row bearing

[Benjamin Choi]

I have a MK2 996 with a reman engine.

I'm curious to know how one can tell if it has the latest IMS bearing design (dual-row) v. the single row in the MK1 3.4s.

Do all 3.6s come with the dual row from '02 onward? Can you tell by the engine #?

[phillipj]

Benjamin,

I have heard that all the 3.6 remans have the new bearing upgrade. I'm sure Jake Raby would know for sure. He might be a good resource.

Edited May 14, 2009 by phillipj

[1schoir]

I have a MK2 996 with a reman engine.

I'm curious to know how one can tell if it has the latest IMS bearing design (dual-row) v. the single row in the MK1 3.4s.

Do all 3.6s come with the dual row from '02 onward? Can you tell by the engine #?

The dual row IMS bearings were mostly on the earlier M96 engines, but it is impossible to be 100% certain without removing the transmission to visually inspect.

IIRC, there is a website that gives engine #'s but it is not completely accurate.

Go to the LNEngineering.com website for details.

Regards, Maurice.

[Benjamin Choi]

So did I have that reversed? The newer design is a single row (simpler, less parts) than the older design with double?

[1schoir]

So did I have that reversed? The newer design is a single row (simpler, less parts) than the older design with double?

Ben:

Yes!

I don't think it was for simplicity or for less parts. They knew they had a problem and have tried various fixes.

That said, if it was cheaper to use a single row bearing, Porsche would not hesitate nowadays. :soapbox:

Regards, Maurice.

[BruceP]

So did I have that reversed? The newer design is a single row (simpler, less parts) than the older design with double?

Ben:

Yes!

I don't think it was for simplicity or for less parts. They knew they had a problem and have tried various fixes.

That said, if it was cheaper to use a single row bearing, Porsche would not hesitate nowadays. :soapbox:

Regards, Maurice.

Dual row bearings are on the earlier motors, single row on the later motors, as previous posters have said.

On LN Engineering's web site, there is a page devoted to the retrofit. On this page, you will find an approximate range of engine numbers for each. There is also a visual way to confirm, if you have the transmission and clutch separated from the engine (obviously not very practical) detailed on that page. Here's the link:

http://www.lnengineering.com/ims.html

Regarding Maurice's comment, I think Porsche is actually much better about this stuff 'nowadays'. However, when the 996 was designed, they were in financial trouble. It shows. It's one reason I have some affection for the car, in my perverse way. The 993 was a transition car that bought Porsche some time, but the 996 literally saved the company. When you consider the impossible circumstances they were operating under, the 996 is a really remarkable car in a lot of important ways. Cheap in spots, for sure (the IMS was a way around having to create separate castings for the right and left heads, for example). But the engineers had their hearts in it. Just my .02 worth of editorial comment. :D

[Benjamin Choi]

When you consider the impossible circumstances they were operating under, the 996 is a really remarkable car in a lot of important ways. Cheap in spots, for sure (the IMS was a way around having to create separate castings for the right and left heads, for example). But the engineers had their hearts in it. Just my .02 worth of editorial comment. :D

Cool perspective, BP.

[1schoir]

When you consider the impossible circumstances they were operating under, the 996 is a really remarkable car in a lot of important ways. Cheap in spots, for sure (the IMS was a way around having to create separate castings for the right and left heads, for example). But the engineers had their hearts in it. Just my .02 worth of editorial comment. :D

Cool perspective, BP.

+1!

Regards, Maurice.

[c70Pete]

your dealer should be able to look up the type of bearing (single or double) based on your engine number