2008 Porsche Cayenne Turbo 957 Cylinder Scoring and Piston Ring Specifications

[andrewjt19]

Hello everyone,
         I can provide more information if needed, but I'm submitting myself to the advice and information of the Porsche community. I have a 957 CTT with cylinder scoring in cylinders 5 and 8. I would like to try and hone the cylinders and replace the rings with larger ones. I have a few questions:

1. What are the stock cylinder sleeves/liners made out of? I understand they are coated with Alusil.
2. What are the steps of the ring gap on all three rings?
3. A place to purchase rings, cylinder sleeves and pistons to insert them myself. 

I'm not a mechanic, but I have family and friends who are and would be assisting. I'm aware of LN Engineering's Nickie's, 928 Motorsports solution and basically rebuild options with larger cylinders and pistons. Please help and thank you. 

[andrewjt19]

Photos of Scoring

[JFP in PA]

33 minutes ago, andrewjt19 said:

Hello everyone,
         I can provide more information if needed, but I'm submitting myself to the advice and information of the Porsche community. I have a 957 CTT with cylinder scoring in cylinders 5 and 8. I would like to try and hone the cylinders and replace the rings with larger ones. I have a few questions:

1. What are the stock cylinder sleeves/liners made out of? I understand they are coated with Alusil.
2. What are the steps of the ring gap on all three rings?
3. A place to purchase rings, cylinder sleeves and pistons to insert them myself. 

I'm not a mechanic, but I have family and friends who are and would be assisting. I'm aware of LN Engineering's Nickie's, 928 Motorsports solution and basically rebuild options with larger cylinders and pistons. Please help and thank you. 

 

I would pretty much forget trying to install new liners yourself, it requires both special equipment and knowledge.  LN Engineering is were most shops send their bare engine cases to have new liners installed.

[andrewjt19]

Thanks buddy for the reply. You've helped me out in the past I appreciate your advice. Do you happen to know though if the stock sleeves are steel? And what the bore size is along with the rings?

[JFP in PA]

1 hour ago, andrewjt19 said:

Thanks buddy for the reply. You've helped me out in the past I appreciate your advice. Do you happen to know though if the stock sleeves are steel? And what the bore size is along with the rings?

 

The sleeves are an alloy of aluminum, with an coating on the inside.  LN's are also an alloy, but completely different construction.  Bore diameter is 96 MM or 3.78 inches.