Alusil Block Hone

[Wh1t3Kn1ght]

As you've done your research, you'll know the original Mahle Alusil coating is long gone. And I don't recall reading of a successful 944 Alusil rebuild, since Wossner had issues a while back. Good luck.

Do you have a link to the information about the Mahle Alusil coating changes?

Like I said above I've seen successful alusil rebuilds with Mahle Motorsport pistons for BMW engines (at the end of the day I understand the blocks are made by the same manufacturer that made the 944 blocks "kolbenschmidt").

I've also been told that the Mahle pistons have the same coating as OE pistons, the same person also told me that Wossner (and others) are/were using a PTFE based coating which isn't suitable for alusil (even though Wossner and others claim it is).

I've reached out to Mahle Motorsport in NA for confirmation before anything gets fitted and built.

EDIT: Mahle Motorsport have replied to my support request confirming that the pistons have a Ferroprint skirt coating which contains iron particles as per the original pistons.

[pauly]

EDIT: Mahle Motorsport have replied to my support request confirming that the pistons have a Ferroprint skirt coating which contains iron particles as per the original pistons.

The original Mahle coating was called Ferostan, but Mahle stopped using it for environmental reasons. And Ferroprint is the replacement that Mahle came up with. Search on Rennlist and contact engine builders on there, if you want to know more about that. Wossners were perhaps cheaper and had shorter lead times, and they worked fine for several years. Though recently they've had issues with their Alusil coating. I don't know if the OEM's are using the same Alusil formulation that Porsche used 30+ years ago, but I did read something about chemical etching rather than polishing the cylinders. I'd be happy to have a working alternative to liners, that partially obstruct the windage ports in 2.7/3.0 blocks.