Nope. I just don’t get it. As loud as the noise is I’d think the issue would stand out like a search light.

 

Still pretty sure the noise is valve train related. Loose rocker arm cups (alloy arms) can not be found with only visual inspection. Try to spin them with small screwdriver or toothpick. Bad if they spin. Visual also does not identify sticky lifters. Simplest way to pinpoint is with Mechanic's stethoscope while engine is running, valve covers off. Probe especially the rocker shaft support pillars.

 

Rockers were just replaced with overhauled ones from TWS

 

Well I finally found the problem. Not sure if it was an installation error or a defect in the sleeve but the number 8 sleeve has separated from the hat section. It’s cracked all the way around right bellow where the piston stops in the bore.

 

Glad you found it, but that's about the worst, isn't it? I'd call the shop and see what they say. Did they build it or only do the machine work?

 

They only did the machine work. I’ll call them Monday to see if they are willing to help out in any way.

 

Who did the machine work, who made the liners? You are in NC right? Get a 4.0 block from Doc Heydary in Asheboro, more reliable than crappy 4.6 blocks.

 

Walker Machine shop in Raleigh. Not certain on the sleeve manufacturer but would guess Melling.

 

Based on what I see I think the machine shop bears the brunt of the responsibility, but I would still expect Melling to warranty the liner. The liner should be a press fit to the engine block and bottomed out on the ledge at the bottom of the liner, and based on the failure it appears likely it is not. Assuming the Mellling top hat is large enough to be part of the clamping surface area from the head and hg then the liner cannot move up. The liner should not be able to move down if it is properly placed in the block because there is ledge the bottom of the liner is supposed to butt up against. Based on your photo I doubt the bottom of the liner was resting against that lip or ledge at the bottom. The press fit should be tight enough that even when hot the block should not expand to the point where the press fit is not still extremely tight (aluminum expands more than steel or cast iron as temperature increases, hence the issues with the original engines.

I would insist that Melling provide a free replacement liner and Walker install it free of charge (correctly this time) and inspect all other liners to make sure they are installed correctly in the block against the bottom ledge.

 

It sounds as if Walker is going to replace the broken liner on their buck. I am really concerned about the others though and sure hate to put this thing back together only to have another one break down the road. I was easily able to pry the hat section out of the block so that I could remove the piston without damaging it or the rings. It looked as though it was fully seated in the groove machined into the block. What concerns me is that there appears to be no or minimal radius at the transition of the lip to the sleeve and there is a sharp corner where the groove was machined into the block. Is there any information out there about how these sleeves should be installed and the block prepped?

Edit: I found Melling's manual and gave LA Sleeve a call. LA sleeve was very nice and gave me piece of mind. Said it was very rare for this to happen and was most likely a result of using too much force to push the sleeve into the block. They also said if the other cylinders haven't failed by now they are most likely fine.