Wiseco K557M865AP Nissan SR20 Turbo Forged Piston Set 86.5mm Bore

The Wiseco K557M865AP is a Professional Series forged piston set for the Nissan SR20 engine, featuring an 86.50 mm (3.405 in.) bore and a 1.260 in. (32.00 mm) compression height.

Wiseco's Professional Series pistons are designed and manufactured in the USA with no compromises. Forged from 2618 aluminum alloy for superior tensile strength and thermal stability, these pistons deliver custom-level performance and durability straight out of the box. Crown thickness and ring land geometry are specifically optimized for forced induction, nitrous oxide, and supercharged builds.

Key Features:

• Forged from 2618 aluminum alloy — engineered and machined in the USA
• ArmorGlide® skirt coating — seizure-resistant, reduces friction, and quieter operation
• 86.50 mm bore / 3.405 in. — 0.020 in. oversize
• 1.260 in. (32.00 mm) compression height
• 0.8661 in. (22 mm) pin diameter — includes pin part #S625
• Precision ring grooves with anti-detonation groove and additional ring seal features
• Forced pin oiling for enhanced wrist pin lubrication under high load
• Fully machined crown features for optimized combustion efficiency
• Compatible with SR20DE and SR20DET engines
• Compression ratio: 11.0:1 (flat-top / FT configuration)
• Stroke: 86 mm (3.386 in.) | Rod length: 136.25 mm (5.364 in.)
• Includes premium ring set #8650XX

Built to withstand heavy to severe duty race conditions, the K557M865AP is the definitive choice for SR20 engine builders seeking maximum reliability and performance under boost. The included premium ring set and wrist pins make this a complete, ready-to-install kit.