L92 Piston Markings, very curious
L92 Piston Markings, very curious My recently acquired L92 engine, wondering what all these #s are on the pistons. Especially curious about what looks like hand inscribed "14?" on one bank, "15?" on the other bank. I say hand inscribed, because on each piston they are slightly different, but still "14?" or "15?". Looks like they're centerpunched in. I thought it was strange.
Anyone know what this is all about?
Anyone know what this is all about?
OK, let me try something to get the full pictures up..... ah, I think I've got it now.
Again, looks like the marks were NOT made by a machine, and a crappy L92 sure isn't a hand built engine. And by all appearances, I was the first guy to ever pull the heads off this engine. But maybe these marking are the norm??
So thanks if someone can shed some light on this.
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Again, looks like the marks were NOT made by a machine, and a crappy L92 sure isn't a hand built engine. And by all appearances, I was the first guy to ever pull the heads off this engine. But maybe these marking are the norm??
So thanks if someone can shed some light on this.
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Last edited by Scotty_82; Sep 6, 2012 at 06:33 PM. Reason: typo
Thanks for the feedback guys.
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Regarding someone being in there before, that would have been my first thought on seeing those hand-made markings, like maybe indicating a need for addn. honing, etc. Or, I thought maybe it was an engine pulled aside for a QC check.... if they even do that. But again, I'm no expert, but looks like the motor hasn't been apart, or should I say, not recently.
The sleeves? I think that's an illusion. By eye, all sleeves look equal. Moot point since the block is busted anyway (starter mount gone), apparent crash damage, which why I got it for real cheap.
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2009 Escalade? Good to know. I was "told" my engine is from a 2008 Escalade, yet it had AFM, and some say it wasn't yet available in Escalades in 2008??
Another mystery about this engine, Looks like it had run like **** for some time. Combustion chambers were crudded up somewhat, lots of black & wet. One sparkplug was even fouled. Inside the valve covers and crankcase, looks like brand new.
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The sleeves? I think that's an illusion. By eye, all sleeves look equal. Moot point since the block is busted anyway (starter mount gone), apparent crash damage, which why I got it for real cheap.
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Another mystery about this engine, Looks like it had run like **** for some time. Combustion chambers were crudded up somewhat, lots of black & wet. One sparkplug was even fouled. Inside the valve covers and crankcase, looks like brand new.
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the dots on the two ?'s are in the exact same pattern, too close to replicate by hand in my opinion. It looks like someone had a single punch to inscribe a "?".
Why someone would have that "?" punch is a total mystery to me...
Why someone would have that "?" punch is a total mystery to me...
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From: Texas and Qatar
That thinner cylinder wall is fairly normal on the 6.2L blocks. Not a fan or saying it's normal, but it's on just about all of them that I've ever seen.
Interesting markings, I never looked or have seen any. I'll be sure to look on the next one I tear into. I like parts that have a "?" on them, lol.
Interesting markings, I never looked or have seen any. I'll be sure to look on the next one I tear into. I like parts that have a "?" on them, lol.
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Further, two pistons have a crooked 1 in front of the 4 & 5s.... realized they too are the same as each other, so they are actually backslashes. So I have 15?, 14?, /5? and /4?, etc.
That thinner cylinder wall is fairly normal on the 6.2L blocks. Not a fan or saying it's normal, but it's on just about all of them that I've ever seen.
Interesting markings, I never looked or have seen any. I'll be sure to look on the next one I tear into. I like parts that have a "?" on them, lol.
Interesting markings, I never looked or have seen any. I'll be sure to look on the next one I tear into. I like parts that have a "?" on them, lol.
