Quote:
Originally Posted by JFP in PA
No, because there is no spec for how much they should move, plus these cylinder liners tend to go oval with wear. The proper way to measure piston to bore clearance is to use a bore gauge to measure the bore at the thrust sides and use a micrometer to measure the piston skirt diameter, subtract one from the other.
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Ah, ok, thanks, never heard it to be but worth a check.
Quote:
Originally Posted by The Radium King
ask yourself what caused the foreign object damage. i'd be suspicious that it was a little piece of piston ring. which means pistons have to come out regardless of what you do about the cyls.
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After some close up pics, it looks like the damage was caused with the engine apart since the indentation starts from outside the edge of the cylinder as would happen without the head and gasket installed. So that would point to mechanic error on a previous repair. I don't think the gouge itself poses too much of a problem but there is also a indentation/scratch parallel to the rings which must cause the rings to move slightly on every engine rotation.
Also, the last pic shows a detail of the silicon in the Lokasil coating. Pretty cool!
Oh, and I've been reading up on bore scoring and I never realized there is life with beginning bore scoring. Many videos with Charles Navarro and Lake Speed talk about using moly in the oil to slow the scoring plus oil analysis to show the progression of scoring so you know when to finally abandon all hope! That's a huge plus at this point and gives me hope about seeing this car run again.
For now, I'm going to borrow a borescope from Autozone and check the bottom of the cylinders to see if there is any scoring still not seen. My situation is unique as my damage appears to have been caused by a hack mechanic and not from traditional M96 methods so hopefully the bottom end(s) are all undamaged.
(Crossing fingers...!)
