Nissan GTR VR38DETT (94.40mm Crank.) 9.5:1 Diamond Forged Pistons w/ H-13 Tool Steel Pins

Out of stock (available on backorder)
Forged Pistons
Brands: .

The Nissan GT-R VR38 pistons are made by Diamond Racing USA. They are built as tough as can be to withstand the vigorous demands of racing. No matter how much boost pressure you are running or how high you are revving, these pistons will take it and ask for more !!To accommodate the rapidly escalating strength requirements, they redesigned the underside of the piston to make it far stronger and they made it a full round design to help stiffen it and spread the higher loading on the cylinder walls. The full round design also resists piston slap and stabilizes the piston in the bore under high cylinder pressures to help the ring package maintain optimum sealing. The new pistons are made from 2618 alloy with very robust pin bosses and under crown milling to achieve equal crown thickness across the piston. The piston skirts are also milled and 3-D radiused.Piston crowns feature 3-D modelled valve pockets in anticipation of bigger cam profiles. They are larger and deeper to ensure adequate piston-to-valve clearance in all applications. Tool steel H13 wrist pins are standard to accommodate applications up to 1600 horsepower. They use tried and true wire locks for ease of assembly and reliable pin retention. Thicker wall pins can be specified when ordering these pistons, up to 0.250-inch wall to accommodate the cylinder pressure of 1600 horsepower. All pin dimensions are 0.905 x 2.500-inch with variable wall thickness as required.The pistons use a full Total Seal ring pack consisting of a 1.2mm steel compression ring in a 0.260-inch down top ring land far enough away to protect the rings from the tremendous heat of highly-boosted combustion. The second ring is a 1.5mm Napier style followed by a 3mm oil ring. The cylinder blocks have integral oil squirters for pin oiling and the pistons are equipped with Diamond’s forced pin oiling feature and multiple drain back ports. Horizontal gas ports are employed on the compression ring land to enhance ring seal and stability.

Product Features and Design

  • 2618 Low-silicon / High expansion alloy for High HP/Boost applications
  • Round skirt design with bottom reinforcing band
  • 3D under crown milling to ensure minimal weight without compromising strength.
  • 3D milling on piston crowns for ready to install finish
  • Over size valve pockets for larger than stock valves and clip cuts on the edge of the pistons
  • Window milling, reduce piston overall weight while maintaining its strength and structural integrity
  • Lateral gas ports for better ring seal
  • Offset pins for quiet operation
  • Molly Skirt coating for friction minimization and skirt wear protection
  • Tool steel H-13 alloy pins (Rockwell hardness around Rc54) Wall Thick. 6.35mm
  • Total Seal Pro-Select 1.20mm x 1.50mm x 3.00mm ring set included

A key distinction is the application of additional performance features on all pistons including those destined for stock rebuilds. Hence, even a stock rebuild gains the robust piston design plus all the standard built-in upgrades such as offset pins, horizontal gas ports, premium ring package, Moly skirt coating, and other features that substantially enhance the performance and reliability of any build level.By bringing such a high level of design quality to the VR38DETT piston line, Diamond has effectively eclipsed all inferior designs while providing the performance features and the superior strength and durability needed for these engines to achieve astonishing power levels and live reliably in that rarified atmosphere.

Optional coatings offered per request.

  • Thermal barrier coating “Blast Off Bronze”
  • Piston side-skirt and under-crown coating
  • Hard Anodized Coating
  • Double diamond coating

Additional information


Bore Size

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Comp Ratio

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Comp Height


Pin Diam.

Dome CCS

Wrist Pin Pn

Piston Material

Ring Thickness