"The piston took out the intake valve plus the lifter on cylinder 6."


Absent a failed connecting rod allowing a piston to be in the wrong place at the wrong time; The only way the piston could have come in contact with the valve is if the valve was in a position it shouldn't have been in.



Seem like the valve stem maybe broke and the valve dropped into the combustion chamber bringing its head into contact with the piston. Could be the valve spring failed and allowed the valve to droop into the cumsbustion chamber a bit.


Have you found the missing valve pieces?


I bought am 87 TD with an engine that had an at speed timing chain failure, it suffered a pair of bent valves, a bent connecting rod, and it broke the camshaft in three pieces.