Another Engine Failure Thread....
Hotshot
Joined: Jan 2002
Posts: 17,988
Likes: 207
From: La La Land
There isn't any reason there HAS to be block damage if just the skirts came apart. So long as the wrist pins remained in place, and didn't gouge the cylinder walls, there's a good chance that he can power hone them ten over, use new Mahle's (good call Kris), rings, bearings, and be ready for another 300,000+.
Pop
Lead Driver
Joined: Jan 2006
Posts: 6,267
Likes: 5
I think the skirts degraded and fell off, I'd be wary of the bottom of the bore, and the chunks getting jammed between the crank and bore...
If the chunks fell into the pan scott free, I think damage will be minimal. The piston may have been having extra lateral motion on the wall, but thats only for a few miles, so it should be alright hopefully. With the skirt missing, the piston would have been twisting in an unintended motion against the wall.
Posting Guru
Joined: Oct 2007
Posts: 2,225
Likes: 1
From: Farmington, Minnesota
Well I figured out what the noise was. Good thing I pulled the motor, because I would have still been trying to figure out what the noise was
. This is what was in the oil pan.
I don't have the heads off to tell what the top of the piston looks like, but those are pieces from the #8 piston. Oh yeah here is my list of what was done:
Stock Injectors
Stock turbo(99.5+)
Stock <acronym title="High Pressure Oil Pump">HPOP</acronym>(17*)
<acronym title="DP Tuner - Down Pipe">DP</acronym> tuner 60T, 80E, 120R, 140E(Drove in 80E 90%)
Regulated Return with fuel bowl delete
OBA
Aeromotive 1000 Black
5/8" lines
thats it for performance altercations
.
Needless to say this sucks. I should have the head pulled off tomorrow or Friday with picture of the top of the piston. Interesting point, the truck never died, it ran until I pulled the motor out, and drove everywhere fine, just a very annoying dead miss. I drove it for about a month and a half like this. It passed a contribution test, and a change in cylinder velocity all the cylinders were under 2.0. But in the mean time, Discuss.
. This is what was in the oil pan.I don't have the heads off to tell what the top of the piston looks like, but those are pieces from the #8 piston. Oh yeah here is my list of what was done:
Stock Injectors
Stock turbo(99.5+)
Stock <acronym title="High Pressure Oil Pump">HPOP</acronym>(17*)
<acronym title="DP Tuner - Down Pipe">DP</acronym> tuner 60T, 80E, 120R, 140E(Drove in 80E 90%)
Regulated Return with fuel bowl delete
OBA
Aeromotive 1000 Black
5/8" lines
thats it for performance altercations
.Needless to say this sucks. I should have the head pulled off tomorrow or Friday with picture of the top of the piston. Interesting point, the truck never died, it ran until I pulled the motor out, and drove everywhere fine, just a very annoying dead miss. I drove it for about a month and a half like this. It passed a contribution test, and a change in cylinder velocity all the cylinders were under 2.0. But in the mean time, Discuss.
I think the skirts degraded and fell off, I'd be wary of the bottom of the bore, and the chunks getting jammed between the crank and bore...
If the chunks fell into the pan scott free, I think damage will be minimal. The piston may have been having extra lateral motion on the wall, but thats only for a few miles, so it should be alright hopefully. With the skirt missing, the piston would have been twisting in an unintended motion against the wall.
If the chunks fell into the pan scott free, I think damage will be minimal. The piston may have been having extra lateral motion on the wall, but thats only for a few miles, so it should be alright hopefully. With the skirt missing, the piston would have been twisting in an unintended motion against the wall.
I have no opinion cause I know nothing...really I have no idea, about the internals.
Lead Driver
Joined: Jan 2006
Posts: 6,267
Likes: 5
1.5 months is nothing compared to the life of the engine.
I'm just guessing the piston probably wore out 10-20x faster during than normal.
Hotshot
Joined: Jan 2002
Posts: 17,988
Likes: 207
From: La La Land
True racing pistons have almost no skirt, anyway.
Yes, you're sure going to hear some slap, but damage? Not unless the pin comes out the bottom of the piston. Then, the pin and rod will beat the heck out of the wall.
Pop
Yes, you're sure going to hear some slap, but damage? Not unless the pin comes out the bottom of the piston. Then, the pin and rod will beat the heck out of the wall.
Pop
Lead Driver
Joined: Jan 2006
Posts: 6,267
Likes: 5
I believe the wrist pin is centered so the sideways thrust is distributed along the piston and bore evenly.
If the skirt is missing, the piston would have the tendency to twist in an unintended way, and could possibly score the wall if it were bad enough.
I cant understand why the piston would fail in that area, theres really no stress there compared to the wrist pin area...
If the skirt is missing, the piston would have the tendency to twist in an unintended way, and could possibly score the wall if it were bad enough.
I cant understand why the piston would fail in that area, theres really no stress there compared to the wrist pin area...
Lead Driver
Joined: Oct 2004
Posts: 7,413
Likes: 1
From: Columbia, MO
I'm lost too as to how only the skirt would break. That just doesn't make any sense at all. Cracks typically start in the bowl, and can spread down through the piston, not the other way around. Perhaps it was just a flaw in the casting...no idea really. Can't believe it was still running though.
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Postmaster
Joined: Nov 2003
Posts: 3,595
Likes: 0
From: Utah County, UT
I have talked to one gentleman a while a few years ago that said he was working on an old international tractor that had one horrific pinging sound to it. Started mid summer when they really needed the tractor. Pulled the head off everything looked fine. Still pinged. Next pulled the pan from the bottom, still everything looked normal. Ran the rest of the summer until they could side line the tractor. Tore it apart and found one of the pistons crackted in half. Intact from top side and bottom. Said more than likely the the pinging came from when the bottom of the piston would come up and slap the top portion causing it to slap the head.
Hopefully with the compression loss on it there wasn't any stress created and you can save the block.
Hopefully with the compression loss on it there wasn't any stress created and you can save the block.
Lead Driver
Joined: Oct 2004
Posts: 7,413
Likes: 1
From: Columbia, MO
Yes. Aftermarket. Mahle makes some. If it were me, I'd make sure to have them coated too, both the tops and skirts. These are from DI: Complete set of 8 Mahle Pistons, standard to .40 over, with PolyDyn Performance Ceramic Coating on tops and PolyDyn PDS Dry Film coated skirts, proper sized rings included: $1199.99
Hotshot
Joined: Jan 2002
Posts: 17,988
Likes: 207
From: La La Land
First, we have to acknowledge that every piston, gasoline or diesel, insignificantly "rocks" in it's bore each time it travels up and down. That said......
It likely significant that this was number eight.
If I had to guess the cause of skirt failure, I'd think it was as a result of excessive wear (thus clearance) on the skirt caused by Ford's "better idea" of a fuel system, especially under higher power conditions. I think that one of the components in the noise we describe as "cackle" is the piston slapping.
My own engine has a mechanical "tick" to it, and has had it from the beginning. I have always suspected it to be "slap". It only takes a couple of thousandths extra clearance to hear it.
Most gasoline engines will go their entire lives with it and never cause a real problem, just an annoyance. My wife's Honda with 188K has had some slap in one slug since 33K, but it's not getting worse. It's just there.
But these are diesels, with higher compression pressures, and therefore quicker, more positive slapping of the skirt, a higher wear factor, thus even more clearance, more slap (more shock), and a greater tendency to develop stress cracks. Heck, it's only aluminum, and probably cast at that! (Anybody know for sure what International uses OEM?)
Then one day, maybe even at idle, bang, you've got some REAL clearance issues!
Though not a common failure with these engines, this COULD happen to any of us.
This is one of the best reasons to become friends with your automotive machinist. How well he "fits" the pistons (and rings) can make all the difference in your future. Though I don't have a power hone, so can't do it myself, I like to be there when this procedure is happening. I'll fit the rings on my own, later.
That's why we have very well-engineered specifications on those blueprints. Stay within them.
Pop
It likely significant that this was number eight.
If I had to guess the cause of skirt failure, I'd think it was as a result of excessive wear (thus clearance) on the skirt caused by Ford's "better idea" of a fuel system, especially under higher power conditions. I think that one of the components in the noise we describe as "cackle" is the piston slapping.
My own engine has a mechanical "tick" to it, and has had it from the beginning. I have always suspected it to be "slap". It only takes a couple of thousandths extra clearance to hear it.
Most gasoline engines will go their entire lives with it and never cause a real problem, just an annoyance. My wife's Honda with 188K has had some slap in one slug since 33K, but it's not getting worse. It's just there.
But these are diesels, with higher compression pressures, and therefore quicker, more positive slapping of the skirt, a higher wear factor, thus even more clearance, more slap (more shock), and a greater tendency to develop stress cracks. Heck, it's only aluminum, and probably cast at that! (Anybody know for sure what International uses OEM?)
Then one day, maybe even at idle, bang, you've got some REAL clearance issues!
Though not a common failure with these engines, this COULD happen to any of us.
This is one of the best reasons to become friends with your automotive machinist. How well he "fits" the pistons (and rings) can make all the difference in your future. Though I don't have a power hone, so can't do it myself, I like to be there when this procedure is happening. I'll fit the rings on my own, later.
That's why we have very well-engineered specifications on those blueprints. Stay within them.
Pop