Mirror bore cylinder lining

Nissan, Ford, VW, and other engine manufactures now use something they call mirror bore instead of the more traditional steel sleeve liners. Molten iron is sprayed on to aluminum cylinder walls to a thickness of 0.2 mm then polished to a mirror like finish. Instead of the normal cross hatching to hold oil film there are microscopic pits that have the same function.

I’m curious if there has been any issues with this technology similar to the problems with nikasil plating.

There doesn’t seem to be any issues. No one seems to be posting about oil consumption problems with these engines.

The nikasil issue was more of a problem with “high sulfur” gasoline forming sulfuric acid than a problem with the lining so when the EPA basically ended the production of cheap high sulpher gas in 2000 the problem was basically solved.

For more information go to BMW Nikasil Engine Damage - M60 8 Cylinder - 540i, 740i and 840i.

I don’t think I would ever buy a vehicle that uses this technology, because you then have a disposable engine which cannot be rebuilt. I try to avoid all-aluminum engines and open-deck designs as well…too difficult to repair when the time comes.

Gotta be reason alum block is used vs iron. On a 4 cyl motor? 50 lbs lighter?

That’s a big “if”. With perhaps a few exceptions, like Hemi camshafts and Hyundai Theta, engines are the most durable parts of the cars these days. Most cars will see their end of life far before the engine fails.

Sure, there will be engine failures requiring replacement due to someone neglecting their maintenance, or continuing to drive in an overheat situation, but that’s not the fault of the engineering. That’s driver error.

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