Strange marks in cylinder wall

Nutter281

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Hi All,

I'll start another thread with more details in a few weeks when time permits, but I'm planning to take on the infamous coyote into my 2009 s197 GT swaparoo "gulp" :)

I got a bare long block out of a 2011 GT with 60k miles for a pretty reasonable price but, turns out, guy who sold it to me didn't share the whole truth and I've uncovered some dirty secrets.

Very long story short: previous owner ran a turbo charger with a bad fuel setup, #7 ran lean and blew up, PO replaced the piston with brand new one, reused all the TTY bolts, honed the cylinder without disassembling the crank and other Pistons (shavings in the crank region) and called it a running engine and sold it to me. Of course, I didn't pull TTY head bolts on a running engine when I bought it cause I was planning on running it as is. I found some light granite dust around some of the intake valves that I didn't notice upon purchase inspection which prompted me to just tear down the engine and rebuild it. Found a second piston that was blown and hadn't been replaced. Failure was piston had a broken chunk of metal between the two compression rings - ran way too lean. I called the guy ready to stop by his house and beat the life out of him and he offered to replace the remaining 7 Pistons with new ones. I took the offer since I'm rebuilding it anyway.
The only positive is that the boneheads didn't ever run the engine after they replaced the one blown piston.

Story was too long. OK, so I honed the block out today and found some strange marks in the cylinder of the piston that was blown/replaced. See picture. I'm typing from phone so I can upload more pictures tonight if that helps. After some pretty intense honing with a medium grit stone hone, that V shape is still present along with what appears to be an imprint of the oil ring. I cannot feel these marks whatsoever and definitely don't catch a fingernail but I'm a bit unnerved that they won't disappear after a good hone job. I can't help but wonder if there was some heat stress that may have caused the steel sleeve to fracture beneath the surface or something.

Anybody seen anything like this before on one of these sleeved aluminum blocks?


Thanks,
Austin
 
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eighty6gt

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Wonder what kind of marks unprotected rod bolts leave as they track down a cylinder when you're beating the piston in with a mallet?
 

Wes06

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Damn that's ugly

It able to be bored out any?
 

01yellerCobra

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Something else to consider is how out of round is that cylinder? It must've gotten pretty hot in order to leave those marks. I'd get it completely checked out before moving forward with it.
 

Nutter281

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I dropped it off at machine shop today for inspection - they were concerned about the little rust trail right where the v shaped marks converge. Going to hot water pressure test tomorrow and let me know if it seals....


Might be cracked block behind the sleeve... Craigslist strikes again!!!!
 
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ford20

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Are those the factory sleeves? I'm confused on what you mean by sleeved aluminium block.
 

crjackson

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Wonder what kind of marks unprotected rod bolts leave as they track down a cylinder when you're beating the piston in with a mallet?

One's that look just like these probably. I've seen similar before too but it's been decades ago.
 

weather man

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The block is actually aluminum with iron-plasma sprayed bores, so it's not a liner in the traditional sense. I've never worked with these blocks but I'm actually surprised that you can recondition them at all. I was under the impression that you could not. The coating is extremely thin on these puppies.

It's done by what is essentially a rotating arc welder is inserted into the cylinder. It uses a wire feed, an electric arc, and compressed air to blast a stream of 35,000-degree iron plasma onto the cylinder walls. The molten iron droplets are tiny, just 20 to 30 microns (0.0008 to 0.0011 inch) in diameter, and they dry in 10-6 seconds(the -6 is an exponent of 10, but I couldn't figure out how to type it in correctly). The wire-fed plasma jet is maneuvered to form the lattice pattern; later the cylinder is diamond-honed for final crosshatching.

This may be information you're already aware of, I'm just putting it out there for those who aren't aware.

Plasma liner is only on the 5.8 block. Not Coyote.
 

crjackson

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Plasma liner is only on the 5.8 block. Not Coyote.

My bad, a ford tech. (actually a service advisor, not a tech.) told me Coyotes were using the same process. Should have researched before posting. A quick Google search would have done the trick. :banginghead:
 
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ford20

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Block is aluminum with steel sleeves from factory right? I'm confused by your confusion

Well yes but there are also aftermarket factory style sleeves so I wasnt sure if the previous owner had the block sleeved when had the turbo on there.
 

Nutter281

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Ahhh now I understand the question - was factory ford Pistons so I 'assume' factory block but that I've already made a few bad assumptions here so far.... LOL


Austin
 

Nutter281

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For anyone who was following this, I took that block to Phase II machine shop in STL while i was up there visiting family and had them check it out. They were pretty nervous about the little crack so they bolted the heads on and pressure tested the block to 80psi. Everything passed and they said it was good to go! In any case, I've since talked myself out of the coyote swap, I've got the balls but not the time to track down every little electrical incompatibility that is going to show up (traction control, AC, cruise control, etc.). i'm going to completely rebuild the bottom end (clevite main bearings, new rod bearings, brand new pistons and rings from Ford (tasca) all new main, rod, head, and cam TTY bolts) then sell the long block and get the ford racing whipple 550 kit for my 3V and call it a day :)

Thanks,
Austin
 

Nutter281

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Come again stang8? I already honed it - what do you mean stock Pistons and rings are useless after honing?

Thanks,
Austin
 
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01yellerCobra

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Why are you going with stock pistons? Why not upgrade since you're there?

Misspelling brought to you by Tapatalk
 

Nutter281

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I would upgrade Pistons and rods if I was keeping the engine but I'm just going to sell it so I don't think it will pay to upgrade them.

Thanks,
Austin
 

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