can valves drop just from old age (roughly 200K miles) from normal driving?
everything with my car was fine and one day i reved to 6k and a valve dropped and blew out my piston.


if its not from old age, how else can valves drop.

it was a b20z block and an old 200K mile gsr head.

 

A valvespring could have broke, a retainer failure. . .

 

but how often to old age motors drop valves? personnally ive never seen it happen.