HKS G-Cupring metal head gasket 90.8mm for RB26DETT on white background
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HKS G-Cupring 90.8mm

HKS
HKS14999-AK037
Hardware - Singles
4 Units In Stock - Ships Next Business Day
$ 50.00
$ 50.00

SKU: 14999-AK037

HKS G-Cupring Head Gasket 90.8mm Bore 1.2mm Thick Nissan Skyline GT-R R32 R33 R34 RB26DETT

The HKS G-Cupring metal head gasket fits RB26DETT engines in Nissan Skyline GT-R models from 1989-2002. This 90.8mm bore gasket with 1.2mm compressed thickness uses a bead-type G-Cup stopper and grommet design for reliable sealing in high-boost and high-compression setups up to 1500+ hp. It suits 86.5-87mm pistons common in stroked RB26 builds.

Key Features

  • G-Cup Stopper Design: Bead-type stopper reinforces cylinder sealing for high-boost applications.
  • Grommet Construction: Folded stopper layer delivers consistent pressure and resists blow-out.
  • 90.8mm Bore Size: Fits 86.5-87mm pistons in stroked RB26 engines.
  • 1.2mm Compressed Thickness: Supports higher compression with aftermarket pistons.
  • Multi-Layer Steel: Stainless steel construction handles heat and provides durability.
  • High-Temp Coating: Enables easy installation and maintains long-term sealing.
  • Made in Japan: Built by HKS to precise quality standards.

Product Notes

  • Part number 14999-AK037 for 90.8mm bore and 1.2mm thickness with ±0.05mm tolerance.
  • Bore compatibility 86.5-87.0mm for 0.8-1.0mm overbore from stock 86.0mm.
  • Single gasket per engine weighs approximately 0.8-1.0 kg.

Installation Notes

  • Professional engine builder installation required.
  • Block and head surfaces need RA 20-30 finish and must be flat.
  • Pair with ARP or HKS head studs and follow HKS torque sequence.

This Part Fits

Year Make Model Submodel
1989-1994 Nissan Skyline GT-R R32 BNR32 RB26DETT
1995-1998 Nissan Skyline GT-R R33 BCNR33 RB26DETT
1999-2002 Nissan Skyline GT-R R34 BNR34 RB26DETT
Universal Nissan RB26DETT Swaps 86.5-87mm bore

Why Choose HKS?

  • JDM brand with decades of RB26 development and motorsport wins.
  • G-Cupring design tested in 1000-2000+ hp RB26 drag and time attack engines.
  • Engineered for reliable sealing in high-boost high-compression RB26 builds.

Frequently Asked Questions

  • Q: What thickness options exist?
    A: 1.2mm standard plus 1.6mm and 2.0mm for lower compression.
  • Q: Does it need head or block machining?
    A: Direct replacement if deck surfaces are flat and clean.
  • Q: Is it reusable?
    A: Metal head gaskets are designed for one-time use.

Shipping & Handling

  • Method: Standard ground shipping.
  • Availability: In stock - ships same or next business day
  • Packaging: Box dimensions approximately 18" × 18" × 2".
  • Weight: Approximately 2-3 lbs package weight.

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