Mahle MS 84-89 Porsche 911 Carrera 3.4L 98mm Bore 74.4mm Stroke 127mm Rod 23mm Pin 43.2cc 11CR - PS98-017

MAHLE Motorsport piston and cylinder kit for the 1984-1989 Porsche 911 Carrera, taking the 3.2L air-cooled flat-six to 3.4L with a 98 mm bore on the factory 74.4 mm stroke. The kit pairs a set of six forged 2618-alloy pistons (PP98-017) with matching PC98-001 cylinders and includes a 1.2 / 1.2 / 3.0 mm performance ring set. It is compatible with dual-plug cylinder heads and high-lift cams (DC80). MAHLE's relationship with Porsche dates back to Porsche's beginning, and MAHLE Motorsport North America drew on that OE and racing experience to develop its air-cooled performance kits. The pistons are machined from forgings with narrower, shorter skirts to reduce weight and friction, and the cylinders are produced and machined to original-equipment tolerances for performance, durability and longevity. These kits are modern adaptations of the original parts, so visual differences from factory components are intentional. Specifications Kit Part Number: PS98-017 (pistons PP98-017, cylinders PC98-001) Bore: 98.00 mm Stroke: 74.4 mm Rod Length: 127 mm Compression Height: 32.8 mm Pin Diameter: 23 mm Crown Volume: 43.2 cc Piston Weight: 457 g Compression Ratio: 11.0:1 (92 cc chamber, calculated at 1 mm below deck) Piston Alloy: 2618 forged aluminum Ring Set: 1.2 / 1.2 / 3.0 mm performance rings, included Clearance Guide: 0.0006-0.0014 in (measured at 0.250 in) Fitment 1984-1989 Porsche 911 Carrera 3.2L