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Old 07-05-2012, 10:36 PM   #1
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Default m-tuned rod with heat damage

comments please

this was #1 rod, and was only one with this heat marking

block was not damaged, crankshaft and camshaft bearing surfaces had scraches/damage
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Last edited by mx594m; 07-05-2012 at 10:48 PM.
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Old 07-05-2012, 10:45 PM   #2
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its done
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Old 07-05-2012, 10:59 PM   #3
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what did you do with it?
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Old 07-05-2012, 11:02 PM   #4
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I have never seen an H-beam failure in our motors before, B6 or BP.

Any chance of what caused the problem?
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Old 07-05-2012, 11:04 PM   #5
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wild guess: no lubrication on crank/bearing with extreme friction?
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Old 07-05-2012, 11:06 PM   #6
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That was what came to mind first, but I'm hardly an expert on the subject. I'm sure OP will give us some insight.
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Old 07-05-2012, 11:55 PM   #7
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Quote:
Originally Posted by viperormiata View Post
That was what came to mind first, but I'm hardly an expert on the subject. I'm sure OP will give us some insight.
mechanical autopsy in process

thoughts - foreign object friction; loss of oil; inadequate cooling; random failure of bearing, crank, rod; ???

first external sign was no oil pressure at speed, followed by expensive noise sounds

oil smells burnt, but no H2O overheat

block is 99 [NB], head is MSM [wrong head gasket???]

damage to other bearing surfaces suggest foreign object

damage to that one, and only to that one, rod suggest local and not systemic root cause

right now I think it started as local failure at #1 rod bearing, and as the bearing was rapidly worn caused secondary damage to other bearing surfaces; that suggests this bearing has been failing for some time

motor had less than 3000 miles since build, included new oil pump

used Mobile 1 full synthetic [euporean blend] for oil change at 1000, 2000 miles

motor ingested a compressor wheel 2000 miles ago, but no sign of damaage to top of pistons, cylinder walls, or rings so probably not a factor
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Old 07-05-2012, 11:57 PM   #8
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How does it still have a bearing hanging from it?
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Old 07-06-2012, 09:15 AM   #9
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Oiling failure. Basically the only way a rod bearing can fail is from touching the crank. There are only a couple ways it can touch the crank. Most likely is local loss of oil pressure be that from something in one of the oil passages or from a bur that broke the skin tension of the oil at the edge of the bearing. Next likely is excessive cylinder pressure vs oil pressure either from lugging or knock.
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Old 07-08-2012, 02:11 PM   #10
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If you started to hear the "expensive noise sounds", based on prior experience, you were <60 seconds away from a ventilated block.
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Old 07-08-2012, 02:19 PM   #11
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my crank had the same heat marks when i was starving my engine for oil...
99 engine too...
my issue was foreign objects in the oil passages/galleys/whatever they're called.

i had a bottom end noise when i stepped on the gas - bearings were obviously shot. oil pump was fucked up (brand new oem pump too)...

i think #1 and #4 get oil first, how does #4 look? any signs of heat or extra wear?

how does the oil pump look?
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Old 07-09-2012, 12:02 AM   #12
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Sav: been there, done that, twice; hate those ventilated blocks

PhillyB: yeah, we suspect foreign debris in the oil, source unidentified at this time
only rod #1 showed these marks, but did trash the crank - have a line on a used crank and possibly a set of new Carrillo's' [or how ever you spell that]

hoping to save the head [lots of labor in porting], depends on how much we have to remove to rebore the cam journals AND if we can get the lifter shims to make it work after - have a rebuild-able spare head if needed

did you do anything special to the block after [assuming you rebuilt on that block]?

oil pump was new, expensive after market performance pump
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Old 07-09-2012, 02:16 AM   #13
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lol. my head was also ported and polished. i still picked up a spare head too. my head has to have the same ---- done - cam caps ground down to remove play in the cam shafts and whatever else needs to be done.

my issue was with stock sized pistons...rebuild has 83.5 wiseco's going in.

my oil pump was shot by the time everything was pulled back out - boundary engineering pump for the new rebuild. mine still isn't done.

i got my new crank from parts group
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Old 07-09-2012, 02:19 AM   #14
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Quote:
Originally Posted by Savington View Post
If you started to hear the "expensive noise sounds", based on prior experience, you were <60 seconds away from a ventilated block.
This gives me a piece of mind. Every time I hear some noise I think to myself "OH ---- IS BLOCK ABOUT TO BLOW?". Then I realize it's coming from some other car

At least now I have only 60 seconds to worry about.
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Old 07-09-2012, 09:33 AM   #15
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I've got no experience at all with this type thing, but that's the kind of damage I would have expected from a bearing being too tight. A few 1000 miles without enough lubrication and the friction eventually takes its toll.

Good luck with the rebuild.
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Old 07-12-2012, 06:30 PM   #16
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Have seen plenty of destroyed boosted engines, but that rod is scary, almost caught on fire, LOL!

Just WOW!

Do have the same rods, just went thru one engine where the machine shop messed up the clearances, the pistons jammed on the engine block.

The rods are still brand new, as if never installed, and it happened at 15 psi with a T3/T4 with 550cc injectors, cylinder head is intact. Whatever it was it is NOT on the quality of the rods.
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