911 I fear I may have lost an engine

getblown5.9 said:
for what its worth, I bent a pushrod in my 24v and developed a definite pop thru both the intake and the exhaust. however it did not cause any of that smoking etc that you have.

also now that i think back, the night i bent the pushrod, at higher rpm my motor sounded exactly like yours did in that video with the very loud popping/machine gun fire LOL.
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Last time I saw smoke like his, The fire dept got called... someone thought the shop was on fire...


Knuckle dragger are you power systems or earth moving, or free lance?
 
Well, I got the engine opened up... and it's fatal. Looks like the fire rings between cylinders 1 and 2 blew putting metal into the cylinders. Most of the debris is gone, but there are still some pieces mashed into the pistons. I can see that the edges of the pistons are hammered over so they don't look round in the bore any more. Why the fire rings let go in a flat cruise, I don't know, but I'm not thinking pump any more.

I took the injectors to a shop this morning, but I'm wondering if I shouldn't just retrieve them. At this point, I'm looking at a full rebuild because there is proably too much bore wear to just hang two new pistons.
 

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My buddy had the same thing happen to his fire rings. Had to replace the head. Thankfully the pistons weren't damaged to bad and the cylinder walls miraculously survived without a scratch.
 
Wow, might make some of us think twice about fire rings?

Any ideas as to why this might have happend?

How long was the head fireringed for? Who did the work and whose gasket and rings did you use?
 
Wow, that sucks!!!!!!!!! I use firerings myself. I wonder what caused that? Good luck on the rebuild.
 
Knuckle dragger are you power systems or earth moving, or free lance?[/QUOTE]

earth moving field service. im contract maintenace for a local coal company
 
i bet if you pull your intake valve there will be a piece of metal stuck to the seat. that will make it huff through the intake. you might pull your exhaust housing off your turbo to make sure a piece didnt get into it.
 
Knuckledragger said:
i bet if you pull your intake valve there will be a piece of metal stuck to the seat. that will make it huff through the intake. you might pull your exhaust housing off your turbo to make sure a piece didnt get into it.
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I looked in the outlet side of the turbo and saw no damage. I pulled the turbo, but couldn't see the vanes. I agree, there has to be at least a nick to a vane.

The intake is clearly showing soot. My guess is that compression was crossing between the two cylinders and coming back out the open intake valve of the adjacent cylinder. That would give me the huffing sound. It also explains why I hearing the sound from both the intake and the exhaust.

I put the engine together 5 years ago (30,000 miles). I used a head gasket and fire rings from Haisley. I have contacted them to see if they have any ideas as to why the rings may have failed. My initial conversation with them suggested that I was supposed to be retorquing the studs twice a year. That is something that I was totally NOT aware of. Frankly, for a street truck, I'm not sure if I want to be retorquing the head that often.
 
BgBlDodge said:
My buddy had the same thing happen to his fire rings. Had to replace the head. Thankfully the pistons weren't damaged to bad and the cylinder walls miraculously survived without a scratch.
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Yep, no damage at all to the bore. Unfortinatly, I'm thinking that I have enough bore wear to not just rehang two new pistons. The cross hatch is gone, so I'm thinking overbore. If you look at the pictures, you can see some erosion on the #2 piston. My guess is that the #1 ring failed and the hot gasses punched through the #2 ring at this point. The plasma must have eroded the piston until the hole opened up.

When we cut the head for the fire rings, it was cut .020. If there is any damage to the head, I'm not sure just how much more we can cut from the head.

I'm at a loss as to why the rings would have failed. The truck was in a flat, unloaded cruise when they failed. I was not accelerating or decelerating, just cruising.
 
Same happened to my buddy. Just suddenly started knocking and pulled the head and found that. His had around 100k on them and had been drag raced for several years running high 12's and spraying up to 50/50 water/meth.
 
if the bore is just smooth w/ no cross-hatch, I would just hone it and put standard pistons and rings in it... a little extra piston/wall clearance never hurt anyone that's pushing some heat into the pistons :)
 
Forrest Nearing said:
if the bore is just smooth w/ no cross-hatch, I would just hone it and put standard pistons and rings in it... a little extra piston/wall clearance never hurt anyone that's pushing some heat into the pistons :)
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After you scope the bore first-obtain wear measurements- RIGHT FORREST??? We don't like our pistons rockin in the bore.$.02
 
Yeah it never hurts to find out hat you're working with. I'd do the same, if its not out of tolerance, hone and put new parts in.
 
Forrest Nearing said:
I would want the cylinders to be round, if that's what you're getting at :confused:
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Yes that is one reason for multiple measurements of the bore- also too much clearance is not too good either......:Cheer:

just sayin Forrest, some do things their way...others do things the same but more detail involved which is why I added that. :pop:
 
RacinDuallie said:
Yes that is one reason for multiple measurements of the bore- also too much clearance is not too good either......:Cheer:

just sayin Forrest, some do things their way...others do things the same but more detail involved which is why I added that. :pop:
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sounded like you were just insulting my intelligence, but whatever...

so what kind of "scope" do you use to verify bore shape? :confused: I've always just used an inside MIC
 
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