Engine knock - tore it open. Pix inside...

[atlantadan]

Had a knock when hot, and only when hot. Pulled the engine and dug into it and didn't find anything that screams "bad bearing", but I did see that the center mains were polished to a mirror like shine. What do you all think?

Rearmost cap has some weird horizontal scars.
https://i.imgur.com/95ZohVql.jpg

Cap 2:
https://i.imgur.com/53B4sv2l.jpg

Cap 3:
https://i.imgur.com/hbwlEWUl.jpg

Cap 4 - has a gouge in it. You can also see the different color of the 'gray' bearing surface up by my thumb. The rest of it has been polished-off
https://i.imgur.com/G1SEZIal.jpg

Front cap:
https://i.imgur.com/q3aV3P8l.jpg

Some of the rod bearings also had horizontal scars:
https://i.imgur.com/AMXHgfTl.jpg

https://i.imgur.com/PdHjHA6l.jpg

All of the rod bearings also had these odd deposits on the bearing surface. Could not be wiped off. Not able to actually feel anything, though
https://i.imgur.com/Vk5Ageal.jpg

https://i.imgur.com/8bGzDa5l.jpg
Cam lobes looked ok. This one looked a bit weird. Probably get it polished pre-install
https://i.imgur.com/5Kzwuecl.jpg

Anyway, if anyone wants to offer any ideas, I'm all ears. I don't want to do this again.

I also noticed a lot of oil-scale on the tops of my pistons. I am going to get the heads checked out and make sure the valve seals are good.

[fullforce]

oil pressure drop when hot?

[atlantadan]

oil pressure drop when hot?
Eh, no more than normal. 28-32psi hot on average.

[72LT1]

What does the crank look like on the journal surfaces? Any coolant leaks internally before? I know Dexcool will kill one fast if it gets in there. Did you check the oil for debris or metallic particles?

[atlantadan]

What does the crank look like on the journal surfaces? Any coolant leaks internally before? I know Dexcool will kill one fast if it gets in there. Did you check the oil for debris or metallic particles?

Journals on the crank looked fresh from the machine shop. No coolant leaks. I cut open the filter and there were tee-tiny flecks of metal in there, which is what led me to pull the engine and tear into it. I also am suspect of the lifters as it appears that some of the external coating on the rollers has started to flake off. Yes, you can catch a nail on these defects. These are Crower 6630 lifters.

https://i.imgur.com/i0zyly8h.jpg

https://i.imgur.com/c1fXmCDh.jpg

https://i.imgur.com/UGzqXuOh.jpg

[Daveyhouse]

That flaking off your lifters is probably what got embedded into your bearings causing those pits. My guess

How did the skirts look on the pistons? Too much piston to wall clearance will also cause a "knock" piston slap

[atlantadan]

Skirts looked practically brand new. There is some scuffing inside the cylinder bores, but nothing outlandish. Pin-to-piston clearance is within spec. Still have not seen anything that points to "well THERE'S the knocker..." which in itself, pisses me off. I'm glad I tore into it because those lifters would have eventually killed the cam and made for large, expensive problems - but that knock I was hearing sounded exactly like a rod. The cam is shot, however.

https://i.imgur.com/YpKHwCoh.jpg

[fullforce]

Did you crank it with the belt off to make sure it wasnt something in the acc drive?

[72LT1]

Any updates on what you suspect or found? Did you contact Crowers and email them pictures of the lifters?

[Falco78]

Man I would be angry if this were my engine, you are handling it much better than me.

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