meissen

Let's play a game of "Guess that ****!"


We recognize the blue gasket. Does the aluminum bits look like bearing material or rings? We only yanked one piston out and the ring looked OK. Also - anyone recognize what the circle piece is? We thought it might go to the oil level sensor but we're not sure. What's pictured in my hand is what we pulled out after only 15 seconds of searching... I'm sure there's a lot more in there.




Here's the carnage of one of the bearings that was spun:


Only got 100 miles out of it. Should've checked the bearings before we put it together - we bought the engine used with "60k" but we never checked the piston rings or the bearings. Not sure how much damage was inflicted by us or was already there, unfortunately.

Kevin Blown 95 TA

Those bearings make baby Jesus cry

ACE1252

That circular piece looks to be part of the oil level sensor.

bw_hunter

Neither the rings nor the bearings are made from aluminum so it can't be them. The circular piece does look like the oil level sensor...they break just by looking at them funny.

If you're sure those pieces are aluminum, there aren't that many places they can come from in an LT engine. The timing cover is a possible source...it has plenty of curved areas that could get shaved by a misbehaving cam chain. Nothing in the bottom end is aluminum...other than the pistons themselves. Better have a look at the bottom of them.

OneShoe50

Oh jeez, I think I'm going to be sick.

I'd take a second look at the bearings, that could be bearing material as it softened and extruded from the sides of the bearing leaving the long strips.

And I agree with bw_hunter, check those pistons if the bearings died from lack of lube the pistons would be close beind.

brianswimmer23

yea this makes me sad.

meissen

Yeah, it was a real painful sight to see. I only had 100 miles on the engine. Purchased it used with "60,000 miles" but it had been sitting in storage for a few years. Very stupidly, we didn't check the bearings.. only thing we touched on the bottom end was replace the oil pump spring with the white spring.

What basically killed it was running the car 4-5 times (not driving, just starting and idling) on 30# injectors with the stock tune. Fuel washed past the cylinder rings and got into the oil causing catastrophic wear to the bearings. Amazingly, the engine temperature never reached higher than 195 degrees in the 100 miles I put on the car.

So, lesson to be learned - never trust what you read on forums like this when people say they heard second hand about someone that can drive untuned on 30# injectors for a short period of time. I only ran for 10-15 minutes total on the 30# injectors before the PCM was recalibrated to handle the injectors but apparently it was too late.

bw_hunter

Running 30# injectors on a tune for 26# injectors will dump approximately 15% more fuel into the engine. I say approximately because the pcm will be trying like crazy to lean that out but won't be able to. It should have run poorly and blown a bit (or a bit more than normal ) black smoke out the tailpipe.

That said, I'm surprised that the failure was due to oil dilution wiping the bearings out. How do the cylinder walls look? I would think they'd be scratched to hades if the oil film was washed off.

I'm sorry you're having the trouble but look on the bright side, no you can mod the thing till it screams....

meissen

Just out of curiosity - if it ran for about 10-15 minutes (we'll even say 30 minutes tops...) through about 8 start ups on those 30# injectors and a CC503 cam with a stock tune, would it make sense that all this fuel got dumped in there? Like I said, the PCM was quickly calibrated for the 30# injectors by the guy who was going to eventually tune my car but I stupidly thought everything was safe as long as I didn't go near WOT.

I'm just curious what everyone thinks because a few guys on my site think something was wrong with the engine prior to my buildup and that what I did just pushed what was already there even further to failure.

The cylinder walls are scratched but they don't look *too bad* to a newbie eye. I'll be taking the block over to a machine shop soon to have them look at it and see if they can just hone it out or if it needs to be bored out. I don't know anything about machine work.

bw_hunter

Those cylinders don't look too bad. How about the bearings, were they blue on the steel shell side?

meissen

Sorry, this is where my newbness comes in. The main bearings? I don't recall seeing any blue anywhere - it was all just bare metal. I had no bronze/brass on any main surfaces of the bearings that we looked at. They all were scratched up but the one pictured in the first post was by far the worst. We knew it was bad when we cracked each bolt loose for the bearings - each time we cracked a bolt loose you could smell this really bad "burnt" smell.

Speaking of which - how do you guys get the bearings loose where the studs for the windage tray are? Extra deep socket? Our deepest sock was still too short.

bw_hunter

Ok, the bearings are a steel shell over which copper is layered and then a lead colored material that used to be called babbit is layered. That babbit material is much softer than the crank surface and will 'wipe' the second the crank touches it. The only thing that let's it survive is the hydraulic effect of of .003 or so inches of oil. If the hydraulic effect goes away for whatever reason, the crank lands on the bearing and starts removing the material. First goes the babbit then the copper. When it hits the steel, things start to heat up and damage to both the bearing shell and the crankshaft. The bearing shell, being much thinner than the crank, turns blue from the high heat generated. The crank, having so much more mass, doesn't heat as much and doesn't turn blue except in extreme cases. If you don't see any blue on the convex side of the bearings then you caught it just in time...maybe there isn't any significant dammage to the crank that a quick grind and polish can't fix.

You're right, you'll need an extra deep 16mm deep socket to get the main bolts off at the windage tray. I think Snap-on sells them...but try Sears as well.

meissen

Thank you for that information! I didn't know about the blue - that makes sense. From what we've seen, sounds like we caught it just in time then. Unfortunately the one crank journal has some gouges in it so I think the crank will have to be machined?



We haven't gotten it torn all the way down yet to see the rest.

Anyway - thanks for all of your help, I really appreciate it!

bw_hunter

Wow, is that the crank journal or the back of the bearing? If that's the crank, it looks bad..maybe to bad to turn down. Your machinist would be a better judge than me lookingn at pictures, though, so better ask him.

The number one main..the one furthest forward, would be the worst of the bunch...it's the fartest from the oil source and the first to be starved....

Good luck!

meissen

You know now that I think about it, I think that might be the back of the bearing... good call. I was snapping pictures while my dad was pulling the stuff apart and looking at the pic I think I see the ridge where the bearing is ontop of the journal. I must have snapped that before he pulled the actual bearing out. That's the #2 main bearing. The #2 was spun but the #1 didn't look as bad if I remember correctly. Honestly, Sunday was such a blur... we backed the car into the garage at 10am and had the engine dropped out of the bottom by 4pm between just my dad and I doing the work at a semi-leisurely pace. Once the engine was out, though, we started hustling to try and get the block torn down to see the bearings. My dad's tearing more of the engine apart today so I'll have to take a look tonight and snap some pics.