Piston Kit JE Pistons 361310 for Nissan RB Series 86.00 mm Bore - 1.220 in. CH 15.50 CC - USA-JE-361310 - JE Pistons Nissan RB Series Piston Kit – 86.00 mm Bore – 1.220 in. CH, 15.50 CC Sport Compact, Import, and European forged pistons from JE Pistons are the result of over 75 years of industry leading experience extended to our range of premium forged pistons for Nissan RB25 Engines. JE Pistons are designed for each specific engine and racing application to provide the ultimate combination of durability and performance. From drift track to drag strip, JE Pistons’ performance has been proven in victory lane time and time again. This piston set is equipped with the following Custom Level Features: Accumulator Groove, Pin Fit, and Skirt Coat. Sport Compact, Import, and European Pistons are engineered, forged, and machined 100% in the USA. Standard Features Forged in the USA using 2618 aluminum, yielding tensile strength and minimal thermal expansion Designed specifically for Nissan RB25 Engines. To provide optimized performance durability Proprietary Forged Side Relief (FSR) forging design minimizes friction and power loss with reduced skirt width and saves additional weight with a shorter wrist pin Includes high-quality wrist pins, locks, and JE Pro Seal premium piston rings Made 100% in the USA Custom Level Features Accumulator Groove A specialty groove between the top and second ring provides added volume for blow-by gases. This helps reduce pressure between the rings, improving top ring seal and minimizing ring flutter at high cylinder pressures. Pin Fit The pin bore is precision honed to attain an exact pin clearance. Clearances typically range from .0003 to .0010 between the wrist pin and pin bore. Skirt Coat Skirt Coat reduces friction and wear on piston skirts and cylinder walls while simultaneously reducing operating noise Specifications Piston Series JE Pistons Cylinder Head 4-VALVE Bore Diameter 86.00 MM Piston Head Type Dome Compression Height 1.220 IN Piston Volume 15.50 CC Piston Material 2618 Piston Quantity 6 Forging Type FSR Ring Set Included Yes Top Compression Ring Thickness 0.0400 IN Second Compression Ring Thickness 0.0480 IN Oil Ring Thickness 0.111 IN Wrist Pin Material 5115 Low Carbon Steel, Case Hardened Wrist Pin Length 2.250 IN Wrist Pin Wall Thickness 0.150 IN Intake Depth .115 IN Intake Diameter 1.460 IN Intake Angle 23 Exhaust Depth .030 Exhaust Diameter 1.280 Exhaust Angle 23 Top Groove Width 0.04000 IN 2nd Groove Width 0.04800 IN Oil Groove Width 0.11100 IN