Valve stem failure

[CDXXVII]

Installed 8 new exhaust valves. 200 miles of street driving the tip broke off #7.
Ever seen this?
Cam, push rods and rockers are stock. No evidence of any piston contact.

[Barry_R]

Who made that valve?
Stainless valves are - with very rare exception - not one piece no matter what the advertisers say.  They have an 8645 steel wafer friction welded to the tip for wear.  Stainless steel is a real bugger to harden.  The tip broke off on your valve, indicating poor welding.

[CDXXVII]

Definitely bad weld. Counter guy at Egge Machine said they were old stock TRW.
None of the markings on the stem provide definite proof though.

[Barry_R]

Old TRW stuff was made in the Danville plant.  I have been there.  They would have a TRW part number clearly stamped/etched on the stem.

[CDXXVII]

I know. The valves are clearly marked with X 3381.
Near as I can tell the old TRW number was 211 1883.

[blykins]

Had it happen on a set of custom Ferreas.  Had checked all the install heights on the head, put the valve seals on, then went to stick the valve up in the guide and the thing exploded.  Called my Ferrea guy and they took care of it, but it was the result of the wrong material being used on the stem, as I do believe the stem is drilled and the tip pressed in on those. 

[CDXXVII]

Brent,
When you discovered the wrong material, did you replace all the valves or just the failed one?

[blykins]

Replaced all of them.