Help identifying cylinders

[derm.1785]

Hi. I’ve managed to buy a set of Mahle cylinders for a rebuild that I’m doing. These were sold as 95mm but they measure 98mm. They don’t look like they have been previously bored out and they don’t show any skirt markings. I can’t see them mentioned on here as anything other than 95mm. I was wondering if they were aftermarket big bore???? The markings stamped are 95ZN1 W16 wth A8 below.

[icarp]

pics would be a big help

[derm.1785]

Originally Posted by icarp

pics would be a big help

I tried to upload some pics but couldn’t. I’ll try when I get home from work.

[derm.1785]

Here you go. They measure 98mm diameter, no other markings that I can see.

[john walker's workshop]

Complete cylinder pic from the top would tell us more. hopefully bored 3.2 carreras without the sealing ring groove.

[derm.1785]

Originally Posted by john walker's workshop

Complete cylinder pic from the top would tell us more. hopefully bored 3.2 carreras without the sealing ring groove.

[derm.1785]

They don’t look like they have been bored out, too thick still

[RobFrost]

98mm 3.2 Nikasil cylinder 1974-1979/80. Mahle documentstion was poor in this period. I believe some 95 designated cylinders were actually made 98mm for the 3.2 engine.

It may be the ++ is the key part of the designation indicating they're 98mm / 3.2 cylinders.

If your German is ok there is a little more info here. http://elferszene.de/showthread.php?t=23781

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[derm.1785]

Originally Posted by RobFrost

98mm 3.2 Nikasil cylinder 1974-1979/80. Mahle documentstion was poor in this period. I believe some 95 designated cylinders were actually made 98mm for the 3.2 engine.

It may be the ++ is the key part of the designation indicating they're 98mm / 3.2 cylinders.

If your German is ok there is a little more info here. Bezeichnung an den Mahle Zylindern beim 3,0 SC - Elfertreff - Das 911 & Porsche Forum

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Thanks for the link, it’s an interesting read and gives me an indication of what I have. I love the idea that the factory built engines based on random shelf picking of core components.

[Schulisco]

Translation with Google Translator:
https://elferszene-de.translate.goog/showthread.php?t=23781&_x_tr_sch=http&_x_tr_sl=de&_x_tr_tl=en&_x_tr_hl=de&_x_tr_pto=wapp

[Flat6pac]

Turbo, 97mm, are based on the 95N1, etc
98 mm are opened for 3.4.
Bruce