Thom

Hi

I searched for older posts on this topic but nothing came up.

Are all 944/968 piston pins identical ?
Here is a pic of one I have to replace ; has anyone out there pins with different printings ? What do these printings mean ?

TIA

Vilhuer

Very likely not. There are several different inside diameter pins used in 928 engines for example. Seems newer engine is thicker wall pins it has. 951 pistons will probably have heaviest pins and 968 good second while early NA engines have lightest. For example 928 S3 pins are some 20g lighter than 968 pins IIRR.

Then there is smaller difference between pins used in similar pistons. This is done to get piston+pin combined weight within desired limit. It seems Porsche grouped same weight pistons into one single engine and then selected pins for them based on piston weight. If piston is heavy pin is light and other way around. There can be several gram weight difference between similar pistons and this is countered by different weight pins. Semingly similar pins can have few grams weight difference. This means that even if you manage to find pin from similar engine end result might be out of range to be acceptable for use without balancing engine rotating assembly.

I have seen several different stampings on seemingly similar pins. They could be manufacturing batch number or something like that. If they are pins weight tolerance group I didn't figure out numbering system for it from three different sets of 968 pistons for example.

In case you need one or few pins I might have something you can use. Have two extra 968, several GTS and full set of S3 pins at least which I don have immediate use for. Since its fairly easy to make lighter pin from heavier one some of these might work.

Thom

Thanks Erkka.

I will pm you if I do not find a solution locally.

Thom

I still need a piston pin. Where can I buy one, preferably new ?

Porsche won't sell me one unless I take all four with four new pistons !

2bridges

careful Thom - you generally don't replace a pin independent of piston in ANY engine. This is why you can't buy them individual.

If you must, you better get your micrometer out and double check everything, length, etc. in addition to basic dimensions and weight.

A pin mis-match or retaining clip mishap could result in catastrophic failure.

good luck

Thom

I know that thanks.
Do you know where I can buy new ones ?