Re: Tappet slide failure Posted by Mike Nieuwoudt on March 08, 1999 at 13:34:34: In Reply to: Tappet slide failure posted by A.S.E. Venema on March 08, 1999 at 11:36:58: Hi Anthony Its called fatigue. Without going to a lot of detail think of every piece of material that experience a cyclic stress (as in valve train components) to be breaking very slowly (called fatigue). The trick is to make the component last for more stress cycles than the intended use, but because its a statistical exercise you sometimes experience a fatigue failure before the intended number of cycles has been done. So the slide has probably reached the end of its fatigue life by experiencing rapid crack growth (final failure). Even though a solid component, the origin of the initial fatigue crack could have been a critically positioned scratch during manufacture, a shrinkage crack after casting or forging, or one of a lot of other causes, so the rest of the slides will not nesecarily break in quick sucsession to the first one. Matter of fact, some, or the rest, of them may never fail before the rest of the engine is totally shot. Cheers,
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