Nykasil or Alusil

[sliminbay]

How do you tell whether you have Nykasil or Alusil cylinders? I have 2.7 from 74 911T that needs to be rebuilt. I heard about magnet test on cylinder walls, but is there stamping or something else? Thank you.
-Steve

[Scott Clarke]

Steve-
You should be able to find a mark on the cylinders that either says "Kobelschmidt" or "Mahle." If they are Kobelschmidt, then they are Alusil.. If they are Mahle, they are probably Nikasil, although Mahle did make some Alusil cylinders as well. Also, the Alusil cylinders are more grey, and Nikasil a brighter silver.
-Scott

[kstylianos]

see thread:

Rering or salvage?

[Scott Clarke]

I stand corrected on the exterior color reference. The above mentioned thread contains much more useful photos. By the way, it should be mentioned that alusil cylinders can be reconditioned by EBS. They are able to finish the cylinder walls with nikasil, even when using alusil cores.

[mtelliott]

[By the way, it should be mentioned that alusil cylinders can be reconditioned by EBS. They are able to finish the cylinder walls with nikasil, even when using alusil cores. [/B][/QUOTE]

I always heard that you have to use certain pistons with certain cyclinders and that you can't mix and match. Therefore, if you refinished Alusil with Nikasil, then you would need new pistons. Am I wrong here?

[kstylianos]

I always heard that you have to use certain pistons with certain cyclinders and that you can't mix and match. Therefore, if you refinished Alusil with Nikasil, then you would need new pistons. Am I wrong here?

You are correct. If you replate the Alusil's with Nikasil, you will need either need new Nikasil or JE pistons. It's not recommended to mix piston types. EBS charges $150/cylinder to replate.

[Wayne 962]

I use a magnet - I can't imagine why you would need another marker or test...

-Wayne