Engine number

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10-15-2007, 08:09 AM

#16

marton

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M28/49 is a motor for a GTS manual
M28/50 is a motor for a GTS auto

Marton

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05-26-2017, 06:08 AM

#17

isakpede

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Quote:

Originally Posted by marton

Hi Alex,

I believe the factory stamped funny stuff on the block when they made a factory rebuild of a motor. I think Jim Bailey knows more.

marton

Hello folks!

Blowing dust of this old thread.

What do you make of the numbers on my engine block? It sits in a 94 GTS.

Isak

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05-26-2017, 07:22 AM

#18

worf928

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Is there a place wherein which we store, for posterity, findings? I have 5+ sets of GTS numbers that I can add in the course of the next few months.

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07-29-2021, 06:00 PM

#19

Mark Anderson

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The engine we just got in appears to have the same NB markings on it as well as the model number stamped at the top

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07-29-2021, 07:03 PM

#20

GregBBRD

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Quote:

Originally Posted by Mark Anderson

The engine we just got in appears to have the same NB markings on it as well as the model number stamped at the top

Interesting!
I think you mentioned that the engine had the valve covers off.
Does it have GT cams?

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07-31-2021, 07:37 PM

#21

928 DesMoines

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Quote:

Originally Posted by Mark Anderson

The engine we just got in appears to have the same NB markings on it as well as the model number stamped at the top

I believe “NB” is stamped on replacement blocks that were replaced under factory warranty during warranty service periods.

At least that is what has been stated on this forum in the past.

”Neu Block” ?

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08-02-2021, 02:34 AM

#22

Darklands

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Neuer Block

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08-03-2021, 04:54 PM

#23

Mark Anderson

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From PCNA today:The following statement is what I received from Porsche AG technical:

This is an exchange engine.

AT means "Austausch" = exchange.

I have no idea what "NB" means on the side. However that is not in connection to the engine stamping.

Best regards/ Mit freundlichen Grüßen,

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08-03-2021, 05:20 PM

#24

GregBBRD

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That's great news, but I'm still amazed that they would grind off a number and restamp it...completely verboten, in this country.

Last edited by GregBBRD; 08-03-2021 at 05:23 PM.

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08-03-2021, 07:36 PM

#25

Tom. M

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Good info for sure.
So, does it have GT cams? or is it perhaps a true 89 GT block with matching pistons etc?

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08-03-2021, 08:00 PM

#26

Mark Anderson

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It seems they are in question

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08-03-2021, 08:37 PM

#27

Tom. M

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so GT's are stamped with 274 and 272 and S4's are stamped 292 and 294 from searching rennlist?

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08-04-2021, 05:42 AM

#28

928cs

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I suppose that you have now dicovered that these are CS cams

291-06
293-06
292-06
294-05.

GT are:
271-01
273-01
272-01
274-01

S4 are:
271-00
273-00
272-00
274-00

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08-06-2021, 11:22 PM

#29

Hilton

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Quote:

Originally Posted by GregBBRD

That's great news, but I'm still amazed that they would grind off a number and restamp it...completely verboten, in this country.

I recall (possibly from @Cheburator?) that Porsche's GTS engine purchase was an exchange program? Is it possible that the factory was re-using blocks and thus forced to grind it down?

My '87 S4 has a warranty block (has the ATR stamp) - but it still has the factory sand-cast surface on the plinth where the number is - however going by the records I think the replacement was early 90's and thus probably there was still a supply of new blocks.