Blown Head Gasket Recovery (no longer) - Massive Engine Failure (!)

[Mullaney]

Good to know. I’ll have to figure out how to check the trans sooner than putting a different motor in. Maybe it did let go.

Also got the pistons out. There is some scuffing but I believe it’s from eating pieces of metal when the motor started to blow apart. There are small fragments of metal suck to the cylinder walls. The “scuff” on the crowns is carbon and can be scraped off.
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Yep, those scuffs look to me like the motor letting go...

 

[gringeltaube]

Doesn't look like carbon to me... missing aluminum it is (!)
Guess that particular piston would have been the next in line, to seize up....

 

[adf5565]

Doesn't look like carbon to me... missing aluminum it is (!)
Guess that particular piston would have been the next in line, to seize up....
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The pictures are definitely deceiving! Here is the same piston after a few passes with a scotch brite pad.

 

[sue]

Can anyone explain this mark on the exhaust valve?
View attachment 925208
A ½”-lockwasher would be about that size... But since this mark is so perfectly centered on the valve head and there are no evident signs on the corresponding piston, I doubt that the engine "ate" a washer... (?)

Again I have been around Reno racers, (Allisons, Merlin’s, with lots of boost)
and tractor pulling. I have to say this is very unique to me for failure of a “stock” engine.
But the beauty of a diesel over a “gas” engine is that you can’t melt a piston by going
“lean”. Ya can by over fueling.
but I don’t see the evidence of heat ……(over fueling)
and the “lock washer” , right up there with finding Bigfoot.

 

[sue]

I was wondering about that valve mark as well. There aren't any lock washers I'm aware of on the motor or turbo, especially ones that would have the potential from getting inside. On piston #7 there is a section on the lower left that seems to me “missing” the soot with some red color which looks odd. By combustion side problem does that include head gasket? Or more like piston/cylinder/injection problem?

Moving over to the passenger side of the block and head (pics below), I have a few valve impact marks in pistons 4 and 6. I’m assuming either the crank bent or something else bent to cause the valves to start opening when the piston was TDC. And strangely a little of the mysterious center valve ring imprinted on the piston too. Along with a red ring on pistons 4 and 8 around the intake valves. Not sure what that is. Also weird is 6 looks cleaner than the rest, with red residue on the head.

IP is a rebuilt 4911 pump that is supposed to be set to standard fueling. In the moments before failure my autometer EGT gauge was <1000. Even when pushing it hard I’ve never had it over 1050. Probe is tapped into the exhaust manifold before the turbo.

I'll lead you know about the heads. I haven't decided yet what I want to do.

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And the carbon above the top ring is normal because if you mic out the top of
most diesels , above the top ring diameter is normally smaller than below the
rings. ( face of the piston gets most of the heat and expands more)
which in heat failure (over fueling or cooling issue) there would normally not be
carbon.

 

[87cr250r]

That amount of scratching on the skirt is definitely not normal for a professionally built engine but it is also not anything that would cause a failure. I believe you are correct that it's caused by debris from the failure.