Nikasil or Alusil
 

I have a 1981 3.0SC ROW engine. Did the rest of world engines use the Nikasil cylinders or the Alusil? I have read that you won't know what cylinders you have till you pull them but I was wondering if anyone had some insight in to this. I am putting together my rebuild project and would love to know before I crack open the engine if I need to spend a couple grand on new cylinders.

Thank You

try posting a picture of what you can see of them from the outside, maybe someone here can help ID them

Try searching for alusil or nikasil on the rebuild forum. Here are a couple of recent threads

http://forums.pelicanparts.com/911-engine-rebuilding-forum/177245-identifying-cylinder.html?highlight=alusil
http://forums.pelicanparts.com/showthread.php?threadid=175104&highlight=alusil

good luck

yes, please search.

My first response to this post from 5 days ago should also help, it links to some other threads as well:

http://forums.pelicanparts.com/911-engine-rebuilding-forum/180615-new-variation-old-question.html

You don't necessarily have to spend money on new P&C's. I know that our host has an opinion that you have to go with new however from what I have read from others, and from local shops here in Denver, you can reuse.

Now, who can do it in Alaska I don't know. But here, they use a place that they have had great success with (i.e. not a problem with them seating).

As well, if you are very, very careful, you can seperate the P&C as a unit.

Just my two cents for today. Of course, I bought new ones. If I only new then what I new now.

Michael

Just to clarify, The opinions (not really rules) for reusing alusil and nikasil are different. Reusing nikasil stuff that is in spec is pretty straightforward. Lots of debate on whether you can reuse alusil stuff. Some people have, but I'm not sure what the most miles someone has on reused alusil is.

Which were you referring to, Michael?

Alusil is where the great debate seems to be. I remember a thread that went on for page after page concerning reusing alusil. Had some in depth scientific study on the reuse. I believe that they concensus was that you could reuse as long as you use a certain paste to do the work.

I now have brand new Nikasil in my engine but in retrospect, I could have saved some substantial $ by going with my Alusils.

Of course, my opinions are just that. I don't have the years of rebuilding experience like many of the members of this board.

I have never seen Alusil used in the 9.8 to 1 comp 3.0. ROW engine. If this engine has never been apart I would bet you have Nikasil.

As for reusing Alusil, of coarse you can. The question is what are your chances of the rings reseating. If the cylinders are nice and you use the factory rings for Alusil your chances are good. Better than 70/30. If you use after market rings or rings designed for Nikasil cylinders your odds go down. Now the only question is "Are you a gambling man?"

Henry,

What happens when your rings don't seat properly? Do you get compression leaks that never get better? Do you do damage to the engine? I'm guessing that the engine would run, just never run to optimum. And if this is the case, what percentage of optimum will you get to? I'm also guessing that you would have emissions problems.

Thoughts?

The biggest problem with rings that don't seat properly is oil consumption. Generally compression rings if gapped properly will seal sufficiently to live with but oil consumption means smoke.

Quote: mtelliott
Rebuilt the same engine twice. Does that count as building two engines for experience!.
one minus and one plus equals 0. After the next one you'll be in the plus column.:)

Henry,

Thanks for the info. I was hopping someone would say that the higher compression row engine would have Nikasil cylinders. I will keep my fingers crossed when I open the engine up. It would be nice to be able to save that money and put it elsewhere in the engine.

Thanks,
John

Not any bearing on thread but here is an interesting article I read a couple months ago.
http://waw.wardsauto.com/ar/auto_boring_trutheverybodys_ideas/index.htm