bwolfZ28

iTrader: (40)

Hey guys I was wondering if you could help me out trying to figure out what caused this issue so I can get it back together and not have this issue. The motor had 2700 miles on it. The oil pressure at hot idle is 45 and 70+ at WOT. The engine ran fine but I noticed a slight tapping from 2-3k only under load. I drained the oil and found large amounts of metal so I pulled it apart.

So to complete the story the first time this motor came from the shop it had 35 miles on it and had 0 oil pressure. So I took it back to them and they "fixed" it and now 2600 miles later and 4 oil changes later here is the damage. I don't know what the clearances were set to. However I found that the bearings were .010 oversize. I have a new LSX block now and I'm doing a whole new build. My plan is to rebuild this one as well and try to recoup some money.

Iron 6.0L block
Eagle Crank
Eagle H Beam Rods
Wiseco -15cc Dish
Here is #3 and #4 rod bearings



and here is the #3 main




Here is another find. The ring land between the top and 2nd ring is bent. #7





top of #7 piston






#7 lower rod bearing



#7 upper rod bearing




All the pistons on passenger side are scuffed like this

1FastBrick

iTrader: (16)

How about providing more details?

Iron or aluminum block?
What crank used?
What Rods used?
What where the bearing clearance's?
What oil pump used?
What Oil used?

How many oil changes?

From the pictures. I would say a machining issue with the crank... It doesn't look like it was properly checked for size. Also looks like the oil holes were not properly deburred either as well as trash went through it.

bwolfZ28

iTrader: (40)

Thread updated.

Oil pump is Chevrolet Performance high volume with shimmed spring and oil is Castrol 10w-40.

imma_stocker

iTrader: (19)

Find another machine shop.

bwolfZ28

iTrader: (40)

Yes most definitely. Another buddy of mine had the same shop do his turbo 408 and it did the same thing. New machine did the fix and its running strong.

bwolfZ28

iTrader: (40)

any idea why that piston ring land is like that??

A.R. Shale Targa

iTrader: (2)

Obvious signs of detonation. Plenty

1FastBrick

iTrader: (16)

Agreed on the detonation now that the pictures have been updated!!!

The bearings also show signs of poor machine work on the crank or was over looked while checking parts for assembly.

bwolfZ28

iTrader: (40)

Are you talking about the piston ring land as far as the detonation goes? I just want to get a good idea so I can prevent anything from happening when the new motor goes in.

1FastBrick

iTrader: (16)

Yes, but also you can see pot marks in the top of the piston.

bwolfZ28

iTrader: (40)

what signs of poor machining on the crank would you suggest? There was times early on maybe 1k miles ago we were having some fueling issues and it got lean for a split second. I guess it doesn't take long to do some damage.

1FastBrick

iTrader: (16)

Look at the bearing on the right side. See how it didn't tear part of it up.

See the #7 upper bearing?

If the journal is not perfectly round you will see those affects.

Common in all the cranks manufactured over seas.
You really have to check the journals over prior to assembly.

bwolfZ28

iTrader: (40)

Ok I gotcha. SO the culprit for the bearings on 3 and 4 was detonation as well? Or just poor machining? How much detonation does it take to destroy bearings so quick?

1FastBrick

iTrader: (16)

Looks like a little bit of both.

We're the oil holes debured after they ground the crank. Every bearing looks like it was not done.

bwolfZ28

iTrader: (40)

I don't know if they deburred it. I let them assemble the shortblock and I did the rest. I'm guessing since the first go round it lasted 35 miles with no boost or WOT pulls it has to have some machining flaws. As far as the detonation goes, there is obvious signs of it and that has to be addressed. I hope the people at my shop weren't driving my car around without my meth hooked up. I run a big nozzle and things can get real lean if that isn't on.

I really appreciate all your help with this.

1FastBrick

iTrader: (16)

Not sure how much detonation it takes to destroy a bearing.

Anything is possible as far as the shop goes.

I never let things out my sight when possible. Other people don't care when they are not paying for it.

1FastBrick

iTrader: (16)

I am wondering about the cylinders on the pass side of the block for all the pistons on that side to look like that.

These are things that would be easier to draw a conclusion on if we knew all the specs.

I would be curious if you get it over to another machine shop what they say about it.

bwolfZ28

iTrader: (40)

yeah I left the rest for them to dis-assemble so I can figure out what went wrong.

1FastBrick

iTrader: (16)

In for the results! lol

Deeohgie69

iTrader: (3)

I'd say that most of that is from detonation imo. I had a gen 4 6.0 that I had just put new rings and bearings in it and did two oil changes within less than 350 miles and the oil looked great. It had 432 miles on it when I did a 45-90mph pull and by the time I realized there was a problem (alternator shot crap and it went lean), it was too late. It completely trashed brand new bearings and the crank needed turned. Detonation is no joke

Here's a pic of what a few seconds can do. Turbo car only around 550rwhp and the clearances were between .022-.023 and the top of my piston looked just like yours. This is #7 & #8 king xp rod bearings.