Did the factory use Alusils or Nikasils?
 

Have an '82 SC and am thinking about rebuild. Is there anyway I can tell if the car has Alusil or Nikasil cylinders w/o removing the engine? Assume that the answer is "No." Then what are the odds that I will find Alusils once I get insidel? Wayne's book, on pg. 54, tells us they are most likely Alusil. But the Pelican technical article online entitled "Extracting Power from the CIS 911" tells us that Alusils were rarely used on CIS cars. Which source is correct?

The factory used both Alusil and Nikasil.

If it's a US spec. SC, most probably you'll find they are Alusil.

If you do a search here or on Rennlist, there is a thread which describes counting the fins on the cylinders and looking for a 'rib' which runs down the center. Although none of these methods will tell for sure, but if you have the 'rib' and either 10 or 11 fins (can't remember which off the top of my head), then most probably they are Alusil.

You can also take off the sump plate/screen, shine a light and see if you can peek at the reflective surface of one of the cylinders. There is a distinct difference in the physical properties between the Alusil and Nikasil.

Here is a good thread with pics:

http://forums.pelicanparts.com/911-engine-rebuilding-forum/113952-rering-salvage.html

Re: Did the factory use Alusils or Nikasils?
 

The article is incorrect in this particular case...

-Wayne