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Anyone have any insight on my mains? Went to change the oil and I was met with loads of mechanic’s glitter Cut the filter apart, same story Didn’t make sense to me because it always had perfect pressure, never made any noise aside from the cammed-LS-sewing-machine sounds, never gave me any issues whatsoever.
Said whatever, pulled the motor out and tore it down.
The mains were flaking apart, and there’s some perpendicular wear up the sides.
I don’t want to slap it back together as-is if something is out of round. What do y’all think? Figure taking it in to have everything checked is my best bet.
We can figure this out. Need some info…
What clearances we’re mains setup at? Thrust also?
What did you use the vehicle for?
Typical rpm you ran the motor at?
Boost?
Nitrous?
What’s the combination…compression, cubic inches, etc?
ARP main bolts or studs?
How do the rod bearings look? Cam bearings also?
It doesn’t look like oil temp was a problem, as I don’t see heat there. throw in as much detail as you can about the setup.
I'm seeing victims of debris in your photos, not sources. Not really seeing any "flaking apart" or really any other bearing failure at all. They look perfectly fine, on their own. Looks like they're full of steel fragments from somewhere else that embedded into them.
Are the rod bearings essentially the same? If so, I'd be looking carefully at the valve train at this point.
We can figure this out. Need some info…
What clearances we’re mains setup at? Thrust also?
What did you use the vehicle for?
Typical rpm you ran the motor at?
Boost?
Nitrous?
What’s the combination…compression, cubic inches, etc?
ARP main bolts or studs?
How do the rod bearings look? Cam bearings also?
It doesn’t look like oil temp was a problem, as I don’t see heat there. throw in as much detail as you can about the setup.
Not sure on clearances/thrust, engine was built by a reputable performance shop in Tampa prior to purchase.
Just my daily driver, occasionally took it out to the strip.
50/50 highway/city miles
I wouldn’t say I took it easy but I didn’t constantly beat the **** out of it either
N/A, no boost or nitrous
Flat tops, not sure on exact compression but I can take some measurements and run the numbers. It’s a factory bore and stroke (6.0L LS2)
ARP main bolts and head bolts
Rod bearings looked perfect. Haven’t looked at the cam bearings yet, the moment you lay an eye on em they need replaced 😂
It definitely wasn’t heat damage or low pressure. It was perfectly fine up until that last oil change.
Here’s some pics of the oil and inside the filter.
I'm seeing victims of debris in your photos, not sources. Not really seeing any "flaking apart" or really any other bearing failure at all. They look perfectly fine, on their own. Looks like they're full of steel fragments from somewhere else that embedded into them.
Are the rod bearings essentially the same? If so, I'd be looking carefully at the valve train at this point.
Per the others, more details would help.
Here’s a higher-res shots of the worst bearing, more details in my reply above
Yup, just the result of embedded metal. The bearing itself is perfectly fine, or at least WAS, before all those chips and debris visited itself upon it.
It's steel. Not a cam bearing. A moving steel part. Look for destroyed rockers, push rods ate up at the ends, damaged valve stem tips, lifter that spun in the tray (most likely this I think), etc.
Yup, just the result of embedded metal. The bearing itself is perfectly fine, or at least WAS, before all those chips and debris visited itself upon it.
It's steel. Not a cam bearing. A moving steel part. Look for destroyed rockers, push rods ate up at the ends, damaged valve stem tips, etc.
I’ll run through everything again. Upon my last inspection, I didn’t find anything out of the ordinary. The entirety of the valvetrain looked STELLAR, but I’ll go over everything with a fine-tooth comb again and give an update. I appreciate the advice
How many miles on the build?
you’ve def got some debris in there from somewhere, but all 5 are roached. Initial impression is it looks like it was set up too tight, or the ARP main bolts took the mains out of round. Got any pics of the thrust surface? Was the car running hotter (coolant temp) than usual?
How many miles on the build?
you’ve def got some debris in there from somewhere, but all 5 are roached. Initial impression is it looks like it was set up too tight, or the ARP main bolts took the mains out of round. Got any pics of the thrust surface? Was the car running hotter (coolant temp) than usual?
Almost 20k on the build.
Biggest fear is throwing it back together as is and facing issues down the line because something is out of round, I just don’t want to foot a huge machine-shop bill if I don’t have to. Definitely understand it’s better to be sure, but I’m trying to do this myself to save a chunk. Call me an idiot, I’m 23 and stubborn 😂
How many miles on the build?
you’ve def got some debris in there from somewhere, but all 5 are roached. Initial impression is it looks like it was set up too tight, or the ARP main bolts took the mains out of round. Got any pics of the thrust surface? Was the car running hotter (coolant temp) than usual?
I’ll shoot some pics of the thrust surface, I’ll be at my shop in a bit.
Wasn’t running any hotter than usual, nothing out of the ordinary aside from the glitter surprise when I pulled the drain plug
Almost 20k on the build.
Biggest fear is throwing it back together as is and facing issues down the line because something is out of round, I just don’t want to foot a huge machine-shop bill if I don’t have to. Definitely understand it’s better to be sure, but I’m trying to do this myself to save a chunk. Call me an idiot, I’m 23 and stubborn 😂
Do you have the tools to check for roundness? It’s not hard with the right tools and patience. You need to go through everything first and figure out where the debris is coming from. Then I can tell you why it happened. Any pics of the thrust bearing surface?
Do you have the tools to check for roundness? It’s not hard with the right tools and patience. You need to go through everything first and figure out where the debris is coming from. Then I can tell you why it happened. Any pics of the thrust bearing surface?
How can I go about checking for roundness? I’ve got a full shop full of tools, just unsure how to go about it properly. I’ve built countless engines, but I always left super detailed stuff like this to the machinists. Decided it’s time I step up and start learning more.
How can I go about checking for roundness? I’ve got a full shop full of tools, just unsure how to go about it properly. I’ve built countless engines, but I always left super detailed stuff like this to the machinists. Decided it’s time I step up and start learning more.
You can use a telescoping gauge and a caliper, or you can use a dial bore gauge and measure one at a time. You’ll want to torque the mains while measuring either way. You could get your machinist to measure the mains for prolly a bill, and be certain what’s what, if you’ve never tried it. This looks like a good time for you to jump in and learn how to me.
How can I go about checking for roundness? I’ve got a full shop full of tools, just unsure how to go about it properly. I’ve built countless engines, but I always left super detailed stuff like this to the machinists. Decided it’s time I step up and start learning more.
There are plenty of resources. Here is just 1 example of how to check the bearing clearance.
You can use a telescoping gauge and a caliper, or you can use a dial bore gauge and measure one at a time. You’ll want to torque the mains while measuring either way. You could get your machinist to measure the mains for prolly a bill, and be certain what’s what, if you’ve never tried it. This looks like a good time for you to jump in and learn how to me.
Might sound like a dumbass here, any reason I couldn’t just torque down the mains with a strip of plastigauge around the circumference? May not be precise enough…
02-15-2024, 07:58 AM
LS2 Main Bearing Failure 
