what made this happen?

 

More info needed.......
How many miles were on them?
Was that from a rebuilt engine?

 

What were the clearances on the rod bearings?

 

6000 miles and rebuilt engine

 

Since the trash that's in them happens to line up conveniently with the oil hole, I'd say that the last motor that was built in that block, blew up; and all somebody did to clean it up, was to tank it. IOW all they did was to pretend to clean it up.

That's debris in the oil passages at build time, being flushed into the bearings. More common than most people would like to admit.

 

Next time try the macro setting on the camera, it wont be so blurry. And fix your date stamp if those pictures were just taken

I agree with the above, thats debris damage. Dirty oil passages. Cleaning, Scrubbing and painting the outside of the block is nice and all but... whats inside is a lot more important.

 

How do the mains look?
And even more important, how's the crank?
What bearings are those?

 

damn did you lock down the maro?..................i got a nice tree fity if you need another one............

looks like you lost oil presure to me, after 6000 miles the filter would have got most of the **** that came out of the oil ways

 

its does have that look of oil starvation, what with the metal swapping parts. BUt, it could very well be the effect of debris. As the oil pressure dropped the fit hit the shan.

 

my oil pump went out on my old moter.....it looked the same way, cept the bearing were stacked

 

[quote=Sonix;3670256]How do the mains look? good
And even more important, how's the crank?good
What bearings are those?rod 1,3,6 others are good
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[quote=jay_d;3670267]damn did you lock down the maro? no just wasnt sounding rgt.

 

No, the mains should look exactly the same as the rods, if any of the abovementioned theories are right.
Post a close up macro pic of main #1, #3, and #5.

 

i paid someone to clean the block. inside and out. washed it out when i got it back.

 

Rod bearings too tight? Wrong clearance shells?
If the mains are ok, i'd be very suspicious.

 

Could have been from junk in the crank oil holes. They run from the mains out to the rod journals. If so the mains would be fine.

RBob.

 

Did you SEE them run rifle brushes or similar down all the passages, and a small toothbrush-size wire brush in the groove behind the cam bearings? That's where the debris lurks.

I always specify that blocks be returned to me, after tanking and machining, with NO plugs or cam bearings in them. Then I load them up along with the crank and take them to the car wash, preferably early in the morning on a bright sunny warm day, along with a gun cleaning kit and so forth, and stop along the way and grab a couple cans of engine degreaser (diesel fuel in a spray can). I rifle-brush EVERY SINGLE oil passage with the cleaner; that's 3 big ones front-to-rear, 5 vertical ones from the cam bearings down to the mains, one tall one from bottom to top of the block at the back, and a few more short ones at the back around the air filter; and the 8 little ones in the crank. Then I car wash every one of those with the high-pressure blast, until I run out of quarters. Then I dry the bores and lifter bores and main saddles and journals with a towel, load it up and take it back home, let it sit out in the sun all day to dry, paint it inside and out, oil the bores, and put the cam bearings and oil passage plugs all back in myself (making sure not to miss the ½" dia one that's about 1" up into the block under the rear main bearing cap).

That pretty much eliminates any possibility of what happened to your motor there.

Looking at your bearings, you have a debris trail right down the center, right in line with the hole. Dead giveaway for leftover debris from the last motor that was built in that block and blew up. Any foreign matter left inside the block, has NOWHERE to go, except RIGHT STRAIGHT INTO the bearings the instant oil begins flowing and dislodges it.

Metal chips don't dissolve in the tank, and they don't float.... and so, if they didn't take the plugs out BEFORE they tanked it, then there's no chance whatsoever that they'll come out in the tank. Like I said, it happens more often than most people would feel comfortable admitting.

Like RBob said, if the mains were still OK but the rods looked like that, then it was the crank that had the trash in it, to start all that. But now, there's trash in the whole thing, so...