Manley Pistons 99.75mm Bore +.25mm Size 8.5:1 Dish Extreme Duty Subaru WRX / STI EJ257

Part #: 632202CE - 4. Manley, the leading aftermarket Subaru piston company, has taken it a step further with the new Turbo Tuff lineup designed specifically for EJ25 engines. Drawing on design improvements from our 'Formula - Won' piston forging, we've crafted the ideal Subaru piston. It can handle the toughest high - boost and high - stress situations, while also running quietly and trouble - free for daily drivers. These pistons are made from 2618 alloy, feature an offset wrist pin design, and have a skirt coating. They come with our standard 2.500' x .180' wall premium chrome moly wrist pin (P/N 42346), and 9310 alloy .210' wall pin upgrades are available. Order the EXTREME DUTY part number, and you'll get pistons equipped with 9310 pins (P/N 42546). Each set includes premium steel top rings, Napier style second rings, and higher tension oil rings for excellent oil control, along with round wire locks. Recommended clearances are .003' for mildly boosted engines and .0035' for highly boosted ones, measured .850' (79/83mm Strokes) and 1.100' (75mm Stroke) from the bottom of the oil ring groove. Manley Subaru EJ257 pistons now use Napier style second rings and higher tension oil rings (by Total Seal) for better oil control.

Using these Manley pistons in your Subaru WRX / STI EJ257 is straightforward. First, make sure to choose the right part number based on your engine's boost level. If you need extreme duty performance, go for the EXTREME DUTY part number. When installing, pay close attention to the recommended clearances. For mildly boosted engines, aim for a .003' clearance, and for highly boosted ones, use a .0035' clearance. This is measured at specific points from the bottom of the oil ring groove. As for maintenance, keep an eye on the oil control. The included Napier style second rings and higher tension oil rings are great at managing oil, but regular oil checks are still a must. Also, check the wrist pins periodically to ensure they're in good condition. If you notice any unusual noises or performance issues, it's a good idea to have your engine inspected right away.