Well THERE'S your problem!

[burning1]

Wait, did he blow half the block off..?

[Paulcet]

REALLY should have gone back and torqued those bolts..... 

[Steel]

In my case it was two quarts in 2300 miles, half street half freeway. I have my full instruments and I never saw an oil light. Basic reason would tell me that a third of the oil can't do the same amount of cooling, but if my light never went on can that mean there was no starvation at the pump? I'm searching for a silver lining here. In a couple of days I'll know if I can return to normal performance or not. I don't know if I'm ready to handle a seize on the road, as a rider, working clutch or no.

[Steel]

UPDATE: I've got my cams out just now to pull shims whose buckets wouldn't rotate, and while pulling the buckets for inspection I could plainly see what looked like glitter in the motor oil. This couldn't be normal, could it? All I could find on the forums was a thread about the first 600 miles, and how it's normal then. I'm getting the impression that something in my engine is/was under a lot of stress.

[burning1]

The reason I recommended UOA is that it would confirm whether or not your engine was seriously damage without a full tear-down. Getting the engine apart isn't terribly difficult, but putting it back together can be a bit of a pain. But if you're seeing a lot of metal in the oil, it's pretty strong indication that something is severely damaged in there.

If you pull it apart now, you may be able to repair it for a moderate cost. Bearings are $5-$10 per half, and a new rod is $50-$70 (may or may not be needed.) This is assuming that your crank is still okay.

Replacing the rod bearings means removing the cams from the engine so that you can get the cam chain off the crank, removing the side covers, and separating the cases. I'm not 100% sure on whether or not the clutch basket needs to come off or not at this point.

Regardless of whether or not you manage to repair the engine, you'll learn something from the process.

[Steel]

After pulling the other followers I did NOT see the same metal flakes present. Maybe the flakes where from fussing at that valve with the shim tool before deciding to pull the cams? I did however see that my two exhaust valves that had zero clearance had buckets that looked like they were wearing and starting to show a brassy color on the outside. The wear appeared even. When I tried to put them back in their places neither would go, I tried encouraging them gently with a rubber mallet, and rotating them with pliers and applying down force. I then tried each intake bucket and they went in easily, came out the same. So I have warped buckets (?) and I can replace them with new ones I suppose.

Does this indicate anything about the condition of my exhaust valves, springs, or other cylinder head components?

PS: Am I "threadjacking"? I'd be happy to start my own thread if so. I felt my issues were related, if not the same to the OP's, but I can also feel the focus moving a bit.

[Steel]

The reason I recommended UOA is that it would confirm whether or not your engine was seriously damage without a full tear-down. Getting the engine apart isn't terribly difficult, but putting it back together can be a bit of a pain. But if you're seeing a lot of metal in the oil, it's pretty strong indication that something is severely damaged in there.

If you pull it apart now, you may be able to repair it for a moderate cost. Bearings are $5-$10 per half, and a new rod is $50-$70 (may or may not be needed.) This is assuming that your crank is still okay.

Replacing the rod bearings means removing the cams from the engine so that you can get the cam chain off the crank, removing the side covers, and separating the cases. I'm not 100% sure on whether or not the clutch basket needs to come off or not at this point.

Regardless of whether or not you manage to repair the engine, you'll learn something from the process.

tl;dnr: I'm a poor kid and I don't like rocking the boat.

Some backstory, and narrative about me: I'm willing to tear down and look, but I want to be as sure as I can be that it's necessary, for my first time especially. My gs is intended to be my daily driver, it's currently my only form of transportation. I have to be frugal with my resources and my downtime, as much as possible. I haven't messed anything up yet being noob, knock on wood, but it would be particularly shitty for me to be meddling and exposing myself to extra expense by f%$king up.

I very appreciate your advice. It's not my intention to be rude when it looks like I'm second guessing you, it's my way of adding details and trying to be sure I was clear, so that your advice still applies.

[Electrojake]

In my case, it went in the middle of a corner with no warning, and put me on the ground before I knew what had happened.
Bent the bike up and dislocated a shoulder in the process.
I'm glad that I came out of it better than the bike did.

It was a catastrophic failure of a relatively stock engine. Yes? 
The important issue is your safety and survivability when pushing a low-tech mill that hard. (I'm assuming the internals were stock?)
Either way, glad you're OK burn1.
Please take the time to heal-up properly before pushing the envelope again.
Take care,
-Ej-

[burning1]

More detail:

Bad rod, removed from engine:



Shame that it came out a little blurry, but the best overview picture for how the rod and crank looked when split:



Detail of the rod and balancer shaft:



Detail of balancer shaft damage:



Detail of damaged rod journal:



Detail of good rod journal and crank bearing:



Detail of crank bearings:



Detail of 'good' rod bearings:

[burning1]

A couple of details to add...

First, the failed piston was about 27mm from top of stroke where I found it; about halfway between TDC and BDC. Crank was rotated near BDC when I found it, so it did appear to spin a little after the piston shattered.



Damaged piston moved freely in the bore when I checked. It could be pushed up and down the bore by hand.

Oil pickup system in the GS seems pretty decent. I can't imagine it sucking in air unless there was less than a quart of oil in the sump. Uncovering the pickup through acceleration or braking would require huge forces, esp since there is a splash guard between the pan and the crank... I'm doubtful that the engine was without oil, though it could have been lacking splash lubrication, low oil pressure, or high oil temperature.

Inspecting the rods, it appears that the big end of the rod is lubricated by the crank, and has a jet designed to spray oil onto the cylinder walls. The small end of the rod and piston skirt appear to be splash lubricated, partially by this jet.

Most of the bearings appear to be in okay condition. I noticed some signs of wear on the crank bearings, but nothing terrible. The non-bent rod had some obvious scouring on the bearing surface, though not the worst I've seen in pictures. Crank bearings seem to be in comparatively good shape.

Looks like this is probably a bottom end failure that resulted in a piston failure. I think we'd have had a much better idea of what went wrong if I had tore the engine down before the whole thing went to hell.

[slipperymongoose]

So we're down to more oil being needed and cooled?

[Electrojake]

Not that I'm a mechanic but. . .
This is a low mileage engine that's properly maintained and is operated in its factory specified RPM range?
I don't get it?
Those photos are frightening.

[mister]

Ej, this is an engine that was run under race conditions with low oil and - one which was a high oil user and which had not been top up in the last few races after damage had been done previously. You cannot cause damage and then subject the bike to similar conditions which caused the damage and expect nothing to go wrong.

Michael

[burning1]

Pretty much what Mister said, although a similar failure is very much possible on a street bike if you let it get low on oil and ignore the indications that something has gone wrong.

[burning1]

For what it's worth, I'm not entirely convinced that this was caused purely by a low oil condition. Everything else in the engine looks very very good. If it is oil maintenance related, it may also be in combination with a oiling weakness in the engine. I'm going to take some detailed photos of the failed rods and see if I can dig out some bits of the bearing to see if there are obvious signs of over-heating and wear associated with lubrication failure.

[twinrat]

Read my reply #27 again i do not believe you had a big end failure it is not discoloured enough .you had a piston skirt failure  for sure . look at your piston where you can see all the oil hole drillings exposed and this never happens unless a piston skirt has failed at this point .seen this before ...check with a magnifying glass and you will not find a single bruise there ,only a crystaline surface  that is oil inpregnated . this is from the crack developing over time ,its just badluck..

[burning1]

I've seen a lot of good theories on what happened. Wish I had torn the engine down before it failed... I think the answers would have been a lot more conclusive.

New photos for everyone...

[burning1]

Detail of big end bearings from broken rod:




Detail of broken rod, showing signs of heat discoloration:



Detail of broken rod, showing wear to the big end and detail of breakage:




Little end of broken rod, showing heat discoloration of pin:



Detail of broken piston & bore showing clean bore, wear on pin bore:

[burning1]

Detail of surviving rod, showing bearing wear:



Detail of surviving rod, showing discoloration of little end:



Detail of surviving piston, showing discoloration of pin:



Detail of surviving piston, showing pin bore wear:



Detail of surviving piston, showing skirt condition:

[Electrojake]

Putting up all those photos & captions is a lot of work.
Thanks for taking the time to post it all.
BTW: I ride like an old hen. I couldn't imagine pushing an engine to that point. Low oil or not.

Thanks for explaining all this stuff too. 
-Ej-