Are these roller cams in our motors known to go bad???

A motor with 157k miles, could the timing chain be worn enough to cause the cam to walk a little.
I have a wierd knock in my motor.
It seems to be tripping the knock sensor and the timing pulled.
No code though.
The most noise using a stethescope is around 1 and 2 and the timing cover.
I had thought of timing chain slapping the cover, but is doesn't really sound like that.
It doesn't sound like the normal bearing knock either.
I don't know how to describe it.
It is vrey wierd sounding and is not even slapping sounding.
I know I am going to have to go through the motor.
I would like to be able to drive it for a while until I decide what course I am going to take.
350? rebuild LB9???
Just not sure what I want to do with her yet.

 

Unless something is seriolsy worn out, roller cam engines cant really "walk the cam"

The front has a retainer that bolts to the block.

The rear is held in check by the distributor.

U could get cam walk from a serioulsy worn distrib gear, if the original managed 157k miles.

If the timing chain is original I would consider it highly suspect.

Get something on the crank so you can slowly turn it back and forth(taking the slack out obvioulsy) and watch to see how much movement u get before the rotor moves in the distrib.

Also could have a stud pulling out of the head or a wounded lifter or rocker with that kind of mileage.

later
Jeremy

 

If you've got "cam walk" your retainer plate would have to be out to lunch. My bet would be on the chain. Get a decent double roller and swap it out. With 157k it should be done noise or not.