Please excuse my ignorance if the question i am about to put upon you good people of PassionFord,is a common fact.A standard cosworth valve,has anyone ever known one to break?I dont mean by dropping or hitting a piston,i mean break as in head snaps off?I have always wondered wether you ever have to replace them if undamaged.Does the fact the item is a two piece affair have any bearing on strength once of the older variety?I do thank you dear chaps sincerely with your eagerly awaited replies.

Cheers.