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Design revision in engine number?

spinnaker

Hockenheim
Joined
19 Apr 2021
Messages
707
I'm familiar with the Porsche engine number decipherer as follows...

997 Carrera 3.6 with engine numbers from M96/0569507475 are the new IMS design.

M96/05 = 997 3.6 Carrera NA
6 = 6 cylinders
9 = design revision
5 = year (2005)
07475 = cumulative production serial

This means some MY2005 benefit and all MY2006 onwards benefit.


997 Carrera S 3.8 with engine numbers from M97/0168509790 are the new IMS design.

M97/01 = 997 3.8 Carrera NA
6 = 6 cylinders
8 = design revision
5 = year (2005)
09790 = cumulative production serial
S" Engine (3.8 ) has designation 'M97", can have the smaller IMS or revised larger IMS bearing:
Engine (3.8 ) number up to M97/01 68509790 has the older IMS bearing and Engine number from M97/01 68509791 has the larger revised IMS.

I have looked at a few cars recently and have been checking the engine numbers to see status with IMS bearings.

I looked at a 2006 (06) car the other week and it had a revision code of 8 whereas the one I am looking at currently is a 2007 (07) car has a revision code of 6.

Is that odd that a newer car would have a new revision code? Both are 3.8l 4S cars. The newer car's cumulative production serial is 250 numbers earlier than the 2006 engine number.

Are those cumulative numbers unique to each model year (i.e. do they reset the cumulative number with each new year digit?

Perhaps I am going over the top with my due diligence here? :dont know:
 
The 9 and 8 refer to the version (size) of the engine not any revision. i.e

9 = the 3.6

8 = the 3.8

I'd always thought that the 5 digit engine numbers were reset for each Model Year and your example seems to confirm that.
 
Ah, that makes sense! However the engine number on the Porsche certificate of authenticity is as follows: 667099xx / M9701 (the x's are numbers, I just don't want to splash someone else's engine number freely online).

Which if formatted as above is:
M9701/6 6 7 099xx

To me this would seem to be:

M97/01 = 997 3.8 Carrera NA
6 = 6 cylinders
6 = design revision
7 = year (2007)
099xx = cumulative production serial

The 6 in the number doesn't match with either the 3.6 or 3.8?

I haven't seen the car yet, but perhaps this is a typo on the cert?
 
Maybe had a replacement engine? My 04 car did.
 
spinnaker said:
To me this would seem to be:

M97/01 = 997 3.8 Carrera NA
6 = 6 cylinders
6 = design revision
7 = year (2007)
099xx = cumulative production serial

The 6 in the number doesn't match with either the 3.6 or 3.8?

I haven't seen the car yet, but perhaps this is a typo on the cert?

It will be a typo as there isn't a 6 in any of the 997 engine versions.

Mistakes on the CoA aren't uncommon.
 
Thanks guys, it probably is a typo.

I'll ask the owner to check on it on the bottom of the engine block.
 
I ran an HPI check and it came back as follows:

M9701/6 8 7 099xx

instead of:

M9701/6 6 7 099xx

To me this would seem to be okay as follows:

M97/01 = 997 3.8 Carrera NA
6 = 6 cylinders
8 = design revision
7 = year (2007)
099xx = cumulative production serial

So it does just look to be a typo on the certificate of authenticity from Porsche (which shows the value in those docs!)

Another mystery solved. Thanks!
 

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