Check out this strange cam bearing wear

[rjrobin2002]

Brought home a 1996 roller 351 block from the junkyard. Pulled the heads at the junkyard and bought a shortblock. Cylinders were stock 4.000 bore with original cross hatch, stock rod bearings with no real wear.

Honed it and put new rings in it while waiting for a new cam.

Had to work pretty hard to get the cam to pop put and look at these cam bearings!!!

How is the rest of the engine so clean if it had this cam bearing failure?

 

[rjrobin2002]

Would loss of oil pressure, over heating, or poor maintenance eat cam bearings first?

All the rod bearings, oil pump, and stock 4.000 bore block and ford pistons make me feel like someone hadn't been in the motor before.

 

[DirtDonk]

Wow, nasty. Could it have happened from an overheating, that did not go far enough to effect everything else? Or perhaps it was never damaged while running, but happened while sitting in the junkyard?
Never actually seen anything like it, so not sure what can cause it.
Maybe just a defect, where they simply were not sized properly, or the cam was defective.
Is it a stock cam? Or could it be a retrofitted aftermarket cam? Did you catch how many miles on the vehicle?

Paul

 

[phred]

The engine in my 78 bronco ate the no 2 cam bearing and it did no damage to anything else. By ate I mean the entire bearing was in pieces in the pan. I don’t see how the cam didn’t break with no support in that journal. The engine had over 200000 miles on it.

 

[B RON CO]

Hi, I spun a cam bearing in an old Bronco many years ago. My machinist said to scrap the block because he couldn't guarantee the new bearing would stay in place. Good luck

 

[Yeller]

That's ugly. I'd certainly be putting cam bearing in it.

@phed there is a certain very popular and in demand 6cyl engine that is known for its robustness that only has a bearing in the front and the rear, but it only runs 2600-3000rpm LOL.

 

[rjrobin2002]

The thermostat was installed backwards, so maybe overheat?

 

[rjrobin2002]

That's ugly. I'd certainly be putting cam bearing in it.

@phed there is a certain very popular and in demand 6cyl engine that is known for its robustness that only has a bearing in the front and the rear, but it only runs 2600-3000rpm LOL.

Now I get to buy a new tool, new part, YouTube learn a new skill, LOL

 

[phred]

Remains of said cam bearing.

 

[rjrobin2002]

Now I'm wanting to flush the oil passages that feed the cam bearings to make sure flow is good.

Should I just blow brake cleaner back towards the oil pump with it removed?

 

[73azbronco]

isnt it impossible to fit a thermostat in backwards?

 

[rjrobin2002]

isnt it impossible to fit a thermostat in backwards?

Looks backwards to me?