This is Porsche 911 (996) Carrera engine. It seems to me that liners can be removed from the block. I think this is a wet liner engine. Am I right?

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  • 1
    If it is, then I would expect to see metal bars to hold the liners in place just in case the crank gets rotated. The friction of the rings can cause the liners to shift but it depends on how the liners are fitted. Some engines the liners are designed to be easily removed , 6 litre diesels come to mind.
    – Solar Mike
    Commented Jun 24, 2021 at 8:39
  • 1
    The space around the cylinders is the water jacket but this engine does no appear to have removable cylinder sleeves.
    – jwh20
    Commented Jun 24, 2021 at 15:35

1 Answer 1


In an effort to reduce costs during production, Porsche utilized a type of insert-mold casting process to directly incorporate Lokasil cylinder liners into the case. While this is a neat way to reduce the total number of parts used in the engine, this design basically casts a wearable part into the engine case. There is no factory replacement for the liners, when they wear, the factory expects you to buy a new engine case. In addition, the design of the cylinder liners allows them to "float" within an area filled with coolant.

Excess vibration and twisting from the normal operation of the engine appears to be causing some cracking in these liners, resulting in a small chunk of the liner breaking off. When this failure happens, you will see oil and coolant begin to mix together or a slight unexplained coolant loss.

If your engine experiences this failure, it can be rebuilt using LN Engineering's Nickasil liners installed. They take your old case, machine out the cracked or damaged Lokasil liners, and install an aluminum Nickies insert, which is stronger and more reliable than the factory cast-in liner.

Porsche parts and info

  • So, all the liners which are available for sale for this engine are aftermarket parts. I thought the liners are removable. Based on your explanation, Porsche doesn't offer genuine spare parts (liners) but in a real wet liner engine (like some diesel engines), you can replace the liners with OEM parts supplied by the factory.
    – LFY MP7.3
    Commented Jun 25, 2021 at 8:13
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    @NarimanAsgharian Yes some engines have the sleeves cast in, some don't.
    – NetServOps
    Commented Jun 25, 2021 at 10:51

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