Technical Brittle valve stems

I aquired an engine , in the back of a truck that I bought, it was an FE with CJ heads! It had been setting out side for years….not sure how many!
Well while tearing it down, I shoved on one of the valve springs and the valve broke off! Actually two of them broke off!
Really! I always thought that valve stems were some of the tuffest metal out there!
Anyone , else , ever seen anything like this?




Bones

 

Those valves look to have been broken for a long time. The stems are rusty on the ends.

 

Yes.
The failure started long ago.
I can almost see the "beach marks" across the top of the stem. It indicates to me that the designed speed of the valve train has been exceeded. Maybe more than once.
If I had to guess, I'd say either the engine had been abused by over revving or it was involved in a runaway WOT engine incident. I'd replace all the valvetrain.
And check for piston damage.

Another curious clue: Who abandons an FE with CJ heads, unless it had issues in the past?

 

I cannot answer that! I bought two junk trucks, can’t say what year , here. When I went to pick them up, that engine was in the back of one of them! Wasn’t a CJ, but did have CJ heads and a 3:98 crank!
When they broke off, it looked like a clean fresh break!
One of the oddest things , ever!
Here is a close up of the break!



Bones

 

Looks like you might have hit them sideways with that hammer in the picture.

 

Eaton valves had a two piece stem friction welded just under the head. The weld was exposed to exhaust gas and would corrode and snap at the weld. I imagine the same thing would happen to an intake in an engine improperly stored.

TRW valves had a hardened tip not exposed to high sulfur exhaust and didn’t have that issue.

 

I’ve spooled a few big irons past their limit and have done the exact same thing but it usually resulted in a dropped valve and m***ive cylinder damage Another thing to look at is heat fatigue like running it way to hot and the motor locks up. My buddy’s sister did that with her car and all the heads popped off of the valves and all hell broke loose.

 

I broke them with my hands, trying to get the head off! Totally freaked me out when they came off in my hand! I never have seen that in all my years of working on engines! I always figured the valve stem was the tuffest metal in the engine!
I used the big old hammer there to check the rest of the valves and they all moved! One or two even popped back into place with spring pressure ! I would have figured, seeing as how the rest of the engine is stuck, that I would have to drive the valves out…..with that big hammer! lol




Bones