Manley 625GR2-1 Platinum Piston Nissan GT-R VR38DETT 95.5mm Grade 2 STD Single

Vehicle Fitment

• 2007-2019 Nissan GT-R (R35, VR38DETT, 3.8L Twin-Turbo V6) - Stock 88.4mm Stroke

Fitment Notes

• WARNING: CRITICAL - BORE GRADE SYSTEM: The VR38DETT uses Nissan's OEM bore grading system (Grade 1, 2, and 3). Grade 2 is the middle bore grade. You MUST check the bore grade numbers stamped on the back of your engine block and order the correct grade piston for each cylinder - do NOT assume all 6 cylinders are the same grade
• This part number (625GR2-1) is Grade 2 only - order 625GR1-1 for Grade 1 bores and 625GR3-1 for Grade 3 bores; most builds require a mix of grades across all 6 cylinders
• Sold individually - this listing is for ONE (1) piston with ring set, wrist pin, and wire lock; order the quantity matching the number of Grade 2 bores in your specific block
• Piston-to-wall clearance range: 0.0032 in.-0.0039 in. across all three grades - confirm actual clearance with your machinist using the measured bore
• This is the Standard Series (GR) version - wrist pin is Premium Chrome Moly (.180 in. wall, P/N 42346); for higher-powered builds requiring greater pin strength, see 625EGR2-1 (Extreme Duty, 9310 alloy .210 in. wall pin)
• Designed for stock 88.4mm stroke VR38DETT builds only - not compatible with stroker cranks using a different stroke
• Wrist pin diameter is 23mm - verify connecting rod pin bore compatibility before pairing with aftermarket rods
• Turbo Tuff/DLC wrist pin upgrades (P/N 42745 .250 in. wall and P/N 42746 .300 in. wall) are available separately for maximum-effort builds
• Will accommodate +1mm valve sizes - compatible with ported heads using slightly larger valves
• No manufacturer warranty - Manley Performance does not offer warranty on pistons due to their performance-oriented intended use
• Professional engine builder installation required

Features

• Platinum Series Standard designation - identical piston body, forging, and geometry to the Extreme Duty (EGR) series; differs only in wrist pin spec - the Standard Series uses a Premium Chrome Moly pin (.180 in. wall) versus the 9310 alloy pin (.210 in. wall) in the Extreme Duty version
• Forged 2618 aluminum alloy construction - delivers maximum high-temperature strength, fatigue resistance, and ring land durability under the sustained high-boost conditions of modified GT-R builds
• Near-flat top piston design (-1.5 cc dome volume) produces a 9.25:1 compression ratio - well-matched for high-boost forced induction builds on pump fuel or E85
• Grade 2 skirt diameter corresponds to OEM VR38DETT Grade 2 bore specification - the mid-range bore grade positioned between Grade 1 (smallest skirt) and Grade 3 (largest skirt)
• Offset wrist pin design reduces piston-to-cylinder wall impact at TDC for quieter cold starts and reduced piston slap during warm-up
• Moly-coated (anti-friction) skirts reduce friction and wear, improving break-in and thermal management throughout the piston's service life
• Pressure balance groove equalizes pressure across the top ring land for consistent ring seal and improved combustion efficiency
• Proprietary multi-step top ring groove machining using "one fixturing" method ensures perfect ring groove-to-skirt squareness and precise groove geometry for maximum ring sealing and power
• Federal Form-Scan gauging used to validate ideal skirt indexing to pinhole and skirt-to-skirt polarity for consistent quality across every unit
• Precise pinhole machining delivers exact compression distance and precise lock ring groove concentricity
• "Contour forging" design provides optimal balance between strength and weight without grain-interrupting internal milling
• Premium Steel top ring set with Napier second ring and 9-13 lb. tension oil ring included

Specifications

• Series: Platinum Series, Standard
• Material: Forged 2618 Aluminum Alloy
• Piston Type: Near-Flat Top (Slight Dish)
• Bore Grade: Grade 2 (middle OEM VR38DETT bore grade)
• Bore Size: 95.5 mm
• Stroke: 88.4 mm (Stock)
• Rod Length: 6.500 in.
• Dome Volume: -1.5 cc
• Compression Ratio: 9.25:1
• Piston Weight: ~449 grams
• Piston-to-Wall Clearance Range: 0.0032 in.-0.0039 in.
• Wrist Pin Series: Standard (Premium Chrome Moly)
• Wrist Pin Material: Premium Chrome Moly
• Wrist Pin Part Number: 42346
• Wrist Pin Wall Thickness: 0.180 in.
• Wrist Pin Weight: 132 grams
• Wrist Pin Length: 2.500 in.
• Wrist Pin Diameter: 23mm
• Skirt Coating: Moly (Anti-Friction)
• Ring Set: Premium Steel Top / Napier Second / 9-13 lb. Tension Oil Ring
• Quantity: 1 (Sold Individually)
• Country of Origin: USA

Included Components

• 1x Manley Platinum Series forged 2618 piston (95.5mm Grade 2, moly-coated skirts)
• 1x Premium Chrome Moly wrist pin (23mm / 0.180 in. wall, P/N 42346)
• 1x Complete ring set (Premium Steel top, Napier second, 9-13 lb. tension oil ring)
• 1x Round wire wrist pin lock

Product Description

The Manley 625GR2-1 is a single Platinum Series Standard forged piston for the Nissan R35 GT-R's VR38DETT 3.8L twin-turbo V6 engine at stock 88.4mm stroke and 95.5mm bore. The "GR2" suffix designates this as the Grade 2 bore variant - the middle bore grade in Nissan's OEM three-grade bore sizing system for the VR38DETT. The Grade 2 skirt diameter sits between Grade 1 (smallest skirt, producing the largest piston-to-wall clearance) and Grade 3 (largest skirt, producing the tightest clearance). The piston-to-wall clearance target of 0.0032-0.0039 in. applies across all three grades; the grade system ensures each piston correctly fits its corresponding factory-bored cylinder.

The 625GR2-1 is the Standard Series variant of the 95.5mm stock-stroke GT-R piston - the key difference from the Extreme Duty (625EGR2-1) is the wrist pin. The Standard version includes Manley's Premium Chrome Moly pin (P/N 42346, 0.180 in. wall, 132 grams), while the Extreme Duty version steps up to a 9310 alloy pin (P/N 42546, 0.210 in. wall, 147 grams) for greater strength under higher pin loading. Both versions use the same forged 2618 piston body, near-flat top design (-1.5 cc, 9.25:1 CR), moly-coated skirts, offset wrist pin, pressure balance groove, and ring set. For most street and moderate power builds, the Standard Series pin is entirely adequate; builders targeting very high power levels or sustained high-boost racing applications should consider the Extreme Duty version.

WARNING: Ordering this piston correctly requires understanding the VR38DETT bore grade system. Nissan stamps each cylinder's bore grade (1, 2, or 3) on the back of the engine block at the factory. Before ordering, identify the bore grade of every cylinder in your specific block - most blocks have a mix of grades across all 6 cylinders. This listing (625GR2-1) is for Grade 2 bores only. Order 625GR1-1 for Grade 1 and 625GR3-1 for Grade 3 bores. This part is sold as a single unit - order the quantity equal to the number of Grade 2 bores in your block. Professional installation by an experienced GT-R engine builder is required. Manley does not offer a warranty on performance pistons.