Wiseco Subaru WRX 4v R/Dome 8.4:1 CR 93mm - Single Piston

Engineered, forged, and machined in the USA from 2618 aluminum for improved tensile strengthArmorGlide? Skirt Coating: seizure resistant, friction reduction, and quieter operationFully machined crown featuresPrecision ring grooves, anti-detonation groove, and additional ring seal improving featuresForced pin oilingDesigned and built to withstand heavy to severe duty performance applications