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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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