Manley Pistons 100.0mm +.50mm Bore 9.8:1 Dish Extreme Duty Subaru WRX / STI EJ257

Part #: 632305CE-4. Our new Turbo Tuff lineup for EJ25 engines makes us the top aftermarket Subaru piston company. We've used design improvements from our 'Formula-Won' piston forging to create the ultimate Subi piston. It can handle high boost and stress, and runs quietly and trouble-free for daily drivers. Like all Manley Subaru pistons, these are made of 2618 alloy, have an offset wrist pin design, skirt coating, and come with a standard 2.500' x .180' wall premium chrome moly wrist pin (P/N 42346). You can also upgrade to 9310 alloy .210' wall pins. Order the EXTREME DUTY part number below. These pistons come with 9310 pins (P/N 42546). Each set includes premium steel top rings, Napier style second rings, and higher tension oil rings for great oil control, along with round wire locks. Recommended clearances are .003' for mildly boosted engines and .0035' for highly boosted engines, measured at .850' (79/83mm Strokes) and 1.100' (75mm Stroke) from the bottom of the oil ring groove. Manley Subaru EJ257 pistons now have Napier style second rings and higher tension oil rings (by Total Seal) for better oil control.

Using these Manley pistons is straightforward. First, make sure to check the recommended clearances based on your engine's boost level. When installing, handle the pistons carefully as they are precision - made parts. For mildly boosted engines, use a clearance of .003', and for highly boosted engines, go for .0035'. The measurement should be taken at specific points from the bottom of the oil ring groove. During maintenance, regularly check the piston rings and wrist pins. If you notice any signs of wear or damage, replace the parts promptly. The 9310 alloy pin upgrade option can offer enhanced performance, but make sure it's compatible with your engine setup. Keep the pistons clean and lubricated to ensure smooth operation and a long lifespan.