Tomei Metal Head Gasket - SR20DET RWD | 87.0mm Bore | 1.0mm Thickness (TA4070-NS08A)

Build your SR20DET engine with confidence using the Tomei metal head gasket. Featuring Tomei's triple-layer super grommet design, this 87.0mm bore, 1.0mm thickness head gasket is engineered for SR20DET rear-wheel-drive applications — providing superior sealing properties for high-performance and high-boost SR20DET builds on Nissan Silvia, 180SX, and SR20-swapped 240SX platforms.

Head Gasket Specifications:

• Bore Size: 87.0mm
• Thickness: 1.0mm
• Construction: Triple-layer metal with super grommet design
• Application: SR20DET RWD (rear-wheel-drive)

Key Features:

• Triple-layer super grommet design
• 87.0mm bore for stock and overbore SR20DET applications
• 1.0mm thickness for compression ratio tuning
• Superior sealing properties for high-boost SR20DET builds
• Metal construction for durability and heat resistance
• Tomei quality and engineering

Performance Benefits:

• Superior Sealing: Triple-layer construction with super grommet design provides reliable sealing under high cylinder pressure
• High-Boost Capable: Metal construction withstands the cylinder pressures of turbocharged SR20DET builds
• Compression Ratio Control: 1.0mm thickness allows precise compression ratio tuning based on piston choice
• Durable: Metal gasket resists blowout and degradation better than composite gaskets
• Heat Resistant: Metal construction handles the thermal cycling of performance SR20DET use

Compression Ratio Chart:

The 1.0mm thickness gasket provides the following compression ratios with common SR20 piston bore sizes:

Note: Compression ratios are approximate and depend on piston dome volume, combustion chamber volume, and deck height. Always verify final compression ratio with your engine builder.

Available Tomei SR20DET Head Gasket Thicknesses:

Tomei offers the SR20DET RWD metal head gasket in multiple thicknesses to accommodate different compression ratio requirements:

• 0.6mm: Higher compression (9.2:1 with 86.0mm piston)
• 1.0mm: Moderate compression (8.9:1 with 86.0mm piston) — this gasket
• 1.2mm: Lower compression (8.7:1 with 86.0mm piston)
• 1.5mm: Low compression (8.5:1 with 86.0mm piston)
• 1.8mm: Very low compression (8.3:1 with 86.0mm piston)

Note: Thicker gaskets lower compression ratio. Select gasket thickness based on your piston choice, target compression ratio, and boost level.

Fitment Information:

• Nissan Silvia S13 — SR20DET
• Nissan Silvia S14 — SR20DET
• Nissan Silvia S15 — SR20DET
• Nissan 180SX RS13 — SR20DET
• Nissan 180SX RPS13 — SR20DET
• Nissan 240SX S13/S14 — SR20DET swap
• Note: RWD SR20DET specific — not for FWD SR20DE/DET applications (B13/B14 Sentra, 200SX)
• Note: Verify bore size and thickness requirements with your engine builder before ordering
• Installation: Professional installation required — head gasket replacement is a major engine service

What's Included:

• Tomei metal head gasket (TA4070-NS08A)
• Note: Head bolts/studs sold separately — always use new head bolts or ARP head studs when replacing head gasket
• Note: Refer to Tomei installation instructions for torque specifications and installation procedure

Installation Notes:

• Professional installation required
• Clean cylinder head and block mating surfaces thoroughly — no old gasket material or debris
• Verify block and head surfaces are flat — resurface if warped
• Use new head bolts or ARP head studs — do not reuse factory head bolts
• Follow Tomei's torque specifications and torque sequence
• Do not use sealant on metal head gasket unless specified by Tomei
• Break in engine properly after head gasket installation

Tomei Triple-Layer Super Grommet Design:

Tomei's metal head gaskets use a triple-layer construction with a super grommet design around the combustion chamber and coolant passages. The triple-layer design consists of a stainless steel core layer sandwiched between two outer layers, with grommets (raised rings) around critical sealing areas. This construction provides superior sealing compared to single-layer or composite gaskets, particularly under the high cylinder pressures of turbocharged SR20DET builds. The metal construction also resists blowout and degradation better than composite gaskets, making it the correct choice for high-boost SR20DET applications.

87.0mm Bore — Stock and Overbore Applications:

The 87.0mm bore size accommodates both stock SR20DET pistons (86.5mm) and mild overbore applications. The RWD SR20DET uses an 86.5mm bore from the factory. A head gasket with an 87.0mm bore provides adequate clearance for the stock bore as well as pistons that are slightly oversized due to machining or intentional overbore. Always verify your piston bore size and select a head gasket bore that provides adequate clearance without excessive overhang.

1.0mm Thickness — Compression Ratio Tuning:

Head gasket thickness is one of the primary variables used to control compression ratio in an engine build. A thicker gasket increases the combustion chamber volume, lowering the compression ratio. A thinner gasket decreases the combustion chamber volume, raising the compression ratio. The 1.0mm thickness is a moderate option suitable for turbocharged SR20DET builds running moderate boost levels (10-15 psi). For higher boost applications, a thicker gasket (1.2mm, 1.5mm, or 1.8mm) may be required to lower compression and prevent detonation. For lower boost or naturally aspirated builds wanting higher compression, the 0.6mm gasket is the appropriate choice.

SR20DET RWD Platform Context:

The SR20DET is the turbocharged variant of Nissan's SR20 engine family, used in the rear-wheel-drive Silvia (S13, S14, S15) and 180SX (RS13, RPS13) in Japan. In North America, the 240SX (S13 and S14) was sold with the naturally aspirated KA24DE engine, making the SR20DET a popular engine swap for 240SX owners seeking the SR20DET's superior power potential, lighter weight, and aftermarket support. The SR20DET's combination of a strong bottom end, responsive turbocharger, and extensive aftermarket support has made it one of the most popular performance engines in the JDM community. The Tomei TA4070-NS08A head gasket is engineered for the RWD SR20DET's specific head bolt pattern and coolant passage layout.

Why Metal Head Gaskets?

Metal head gaskets (MHG) are the standard for high-performance and turbocharged engine builds due to their superior sealing properties and durability compared to composite gaskets. Metal gaskets resist blowout under high cylinder pressure, handle thermal cycling better, and provide a more consistent seal over the gasket's service life. For SR20DET builds running elevated boost levels, a metal head gasket is essential for reliable, long-term sealing — the factory composite gasket is a common failure point on modified SR20DET engines running above stock boost.

Why Tomei?

Tomei is one of Japan's most respected performance engine component manufacturers, with decades of motorsport and street performance heritage. Their metal head gaskets are trusted by professional engine builders and enthusiasts worldwide for quality construction, correct fitment, and reliable sealing performance. Tomei's engineering expertise and commitment to quality make their head gaskets a benchmark choice for SR20DET engine builds.

Perfect For:

• Nissan Silvia S13, S14, and S15 SR20DET engine builds and rebuilds
• Nissan 180SX RS13 and RPS13 SR20DET builds
• Nissan 240SX S13/S14 with SR20DET swap requiring correct RWD head gasket
• High-boost SR20DET builds needing Tomei triple-layer super grommet sealing
• SR20DET engine rebuilds requiring 87.0mm bore, 1.0mm thickness metal head gasket

Perfect For: Nissan Silvia S13/S14/S15, 180SX, and SR20-swapped 240SX builds requiring Tomei metal head gasket in 87.0mm bore, 1.0mm thickness for reliable high-boost sealing and compression ratio control.

Pro Tip: Always use new head bolts or upgrade to ARP head studs when replacing a head gasket — reusing factory head bolts risks inadequate clamping force and head gasket failure. ARP head studs provide superior clamping force and are reusable, making them the preferred choice for performance SR20DET builds.

87.0mm Bore | 1.0mm Thickness: Triple-layer super grommet. RWD SR20DET. Silvia S13/S14/S15, 180SX RS13/RPS13, 240SX SR20 swap. Not for FWD SR20 applications. Professional installation required. Use new head bolts or ARP studs.

Build your RWD SR20DET with Tomei quality — metal head gasket, 87.0mm bore, 1.0mm thickness, triple-layer super grommet design for superior sealing on Silvia, 180SX, and SR20-swapped 240SX.