Impreza WRX STI F4-2.5L DOHC Turbo (2007)
Piston Ring: Specifications
Piston ring
Ring closed gap
Top ring
Standard ....................................................................................................................................................... 0.20 - 0.25 mm (0.0079 - 0.0098 in)
Limit ......................................................................................................................................................................................... 1.0 mm (0.039 in)
Second ring
Standard ........................................................................................................................................................... 0.37 - 0.52 mm (0.015 - 0.020 in)
Limit ......................................................................................................................................................................................... 1.0 mm (0.039 in)
Oil ring
Standard ....................................................................................................................................................... 0.20 - 0.50 mm (0.0079 - 0.0197 in)
Limit ......................................................................................................................................................................................... 1.5 mm (0.059 in)
Ring groove gap
Top ring
Standard ....................................................................................................................................................... 0.04 - 0.08 mm (0.0016 - 0.0031 in)
Limit ..................................................................................................................................................................................... 0.15 mm (0.0059 in)
Second ring
Standard ................................................................................................................................................... 0.030 - 0.070 mm (0.0012 - 0.0028 in)
Limit ..................................................................................................................................................................................... 0.15 mm (0.0059 in)
