Found a week spot on zetec, its the conrod bolts so all you people running a zetec its worth changing them. Good job i have a new block with forged pistons and steel rods ready to go in.

Slapping a turbo on a stock standard highish compression NA engine is bound to break the bottom end eventually.

[Edited on 13/4/08 by CaptainJosh]

Did lower compression ratio, was expecting standard pistons giving up first.

It's normally over revving which breaks big end bolts. The piston has too much momentum when changing direction and will stretch/break big end bolts. Check for signs of wear on the "wrong" shells i.e. the lower of the big end shells.

Over loading will show signs of wear on upper big end shells and lower main bearing shells.

Davie