Editing Saturn I4 engine (section)

===Connecting rods and pistons===
From 1991 to 1998 the [[connecting rod]]s were [[forged steel]] with standard type crank pin bearings. SOHC engines during that period used a dished piston design whereas the twin cam engines used a flat top piston with 2 recesses for the intake valves. Twin cam pistons received several re-designs throughout the production run aimed at reducing oil consumption issues. These included reducing the clearance between the top of the piston and the first compression ring, redesigning the skirts on the pistons and the oiling ports on the bottom of the pistons. For the 1999 model year all pistons were totally redesigned. Both engines used the flat top pistons with 2 valve recesses and featured a new hypereutectic design with coated skirts. Also for 1999 all connecting rods switched to a slightly longer powder forged design and cracked bearing caps. The piston pins floated in the connecting rod bushings. The pistons were cast aluminum alloy with the piston pins being retained with snap rings.