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Forum namePerformance/Engine
Topic subjectrod bearing mushroomed, but not spun???wtf
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i5&topic_id=110063
110063, rod bearing mushroomed, but not spun???wtf
Posted by twinvenges, Sep-18-08 04:09 PM
what happend: oil was low (my stupid ass fault...and im sure it caused this...
)
Driving, then i got on it alittle hard for a few seconds, then once i slowed, and parked, i started to hear it..a knock. i limp home.

Engine :
Built Je Piston
Eagle rods
Clevite 77 bearings

so i dropped the pan, and Blam..slight shavings...they are mostly under cyl 1 (closest to drive side). i remove the rod cap/beariing, and a chunk falls out of the oil hole in the rod!! I can see the bearing is smooshed, but not spun, like it melted and or was soft. I examined the crankshaft journal, and strangely...it looks pristine..i cant detect any scratches or gouges in the journal..the chunk must have been boobling inside the oil hole. the bearing halves almost appear to have melted slightly. the inner bearing surface is lke a flaky metallic substance, and i think t saved my journal... has anyone ever seen the smooshed bearing? ill post pix later.. so im thinkin i should order new bearings (the size i need, and plastiguage it..what do you think? should change to a different bearing? mm guessing the bearings were on their way out..
110064, RE: my rod bearing mushroomed???wtf
Posted by Slo2g, Sep-18-08 04:46 PM
Mine did almost the same thing, instead of mushrooming it just failed. I couldn't hear anything because of my open downpipe. Once I could hear it, it was too late. I'm now in the process of rebuilding again. Mine plastigauged out to spec too. I guess its just one of those things. :(
110066, RE: my rod bearing mushroomed???wtf
Posted by twinvenges, Sep-18-08 05:01 PM
hmm, yea, mine didnt spin, i guess they were on their way tho....im thinking a little oil starvation caused this. slo, what was the cause of ur issues? im just thinking i cought it b4 a spin, and can get new bearings..
110069, RE: my rod bearing mushroomed???wtf
Posted by xcasbonx, Sep-19-08 02:44 AM
Just because the bearing doesn't look "spun" does not mean it didn't fail. Also just because you didn't see any gouges or marks on the crankshaft journal does not mean its okay to slap a new bearing in there plastigage it and move on. Chances are you will have another bearing failure months down the road if you half-ass it.

When I spun a rod bearing I went ahead and got a brand new crankshaft, I was building my motor at the time anyway. That made me feel more confident about not having a problem later down the road.
110070, RE: my rod bearing mushroomed???wtf
Posted by azdave, Sep-19-08 03:48 AM
Here is what eventually happens when you try to just put in a new rod bearing and hope it works out.

The whole motor was full of chips and every bearing was showing signs of failure at this point. This is from my GSX I'm bringing back to life.







110071, RE: my rod bearing mushroomed???wtf
Posted by twinvenges, Sep-19-08 09:07 AM
dam, well, the main idea( i should have noted it above lol) is to get it operational, limp it to an empty garage (~45 mins away), and pull motor, and turn the crank. yea, with what i want to push on this motor, theres no way i would slap new bearing on there and call it a day lol. i cant remember what i used on the build tho.. they are .002, so i believe thats around stock, and ill have it turned, to the next size, .010? i cant figure out what bran i used , ,it just says EH, STD .002.. i thought it was clevite, but, i dont think they are..whats ur opinon on clevite 77's?
110072, RE: my rod bearing mushroomed???wtf
Posted by bullettdsm, Sep-19-08 09:39 AM
Just put in a set of bearings and take a shot. What's it like $40 for bearings a couple hours work? I've done this with various different cars on various occasions. Most times, its worked. The last time was on my NA. Ran for like 5k more miles before I did a power rebuild (not because of bearing).

If the bearing is as you said, and the journal is as you said, that should get you around for a bit.

110073, RE: my rod bearing mushroomed???wtf
Posted by twinvenges, Sep-19-08 11:14 AM
my next? is how do i know what size to get.. im guessing STD, since the bearing says" eh STD od.002 and where might i get them? is the OD .002 an OEM spec?
110074, RE: my rod bearing mushroomed???wtf
Posted by Star Turbo Talon, Sep-19-08 04:42 PM
That flakey metal your talking about is red hot metal that separated from the bearing itself. Def not good.
110075, RE: my rod bearing mushroomed???wtf
Posted by twinvenges, Sep-19-08 06:16 PM
yea, i figured...low oil prolly caused it to get super hot and go thermal...
110079, RE: my rod bearing mushroomed???wtf
Posted by Slo2g, Sep-20-08 01:40 PM
Mine was from starvation I think. Mine didn't separate the rod cap from the rod but it sure did turn colors. I am getting another crank and rebuilding the entire engine. Like dave said, that metal flake is in more places than you think.
110080, RE: my rod bearing mushroomed???wtf
Posted by twinvenges, Sep-20-08 04:16 PM
i just checke d with plasti, and it came back fine. like said above, ive put new bearing in, and im gunna limp it to the garage, pull it, and have the crank turned.