Piston ID - 98mm Turbo?

[andrew15]

Hi Guys and Gals - I just finished taking apart a 3.3 Turbo engine that had a bit of fire damage - luckily the engine survived, but I wasn't sure what condition it was in, so I took it apart today.

So far some good stuff -
twin plugged heads with 39/38 ports, titanium retianers, etc
Fabspeed Muffler and GHL headers
Kokeln intercooler
ARP Headstuds and rod bolts
Really nice turbo oil pump
etc - basically some good stuff

The really nice part is that it looks to have been rebuilt recently and with new Mahle P&Cs - the cylinders still show cross hatching and the pistons have most of their machined grooves on the sides.

That said - what are they?
The Cylinders are fully finned and the pistons are marked:
91005441
303-00-1
25383
2273
and stamped with the measure 97.945 - 98mm P&Cs

Did Mahle make different compressions for a Turbo setup or are they all the same?

Thanks
Andrew M

[spuggy]

Originally Posted by andrew15

The Cylinders are fully finned

Might be 965 cylinders, they went fully-finned.

Originally Posted by andrew15

Did Mahle make different compressions for a Turbo setup or are they all the same?

Think I remember from somewhere that Mahle did a 3.4 kit with a choice of 7.5:1 or 8:1, but someone who knows what they're talking about will probably be along in a while

[Steve@Rennsport]

Those look like the Ruf 98mm pistons which have an abbreviated skirt, compared to the regular ones.

[EBS_Don]

I have a Ruf sample here and the skirts are actually shorter than that. This is likely the standard Mahle Motorsport 7.5:1 piston. The 3.4 DME skirt is about the same length as your pics.

Don