MWM Acteon Workshop Manual page 86

Pistons and Connecting Rods
Check the ring grooves, pin housing and the skirt of
the piston. Check the clearance of the rings in the
piston grooves.
Lubricate the liners and piston rings. When installing
the piston / connecting rod set in the cylinder, mind
the correct assembly position. The arrow on to top of
the piston must point toward the flywheel side.
Before installing the pistons in the cylinders, position
the ends of the rings in the direction of the pin, displaced
180° to each other.
9.612.0.006.7160 - 05/04