BLOX Racing Performance Valve Spring - Honda/Acura B18A / B18B / B20 DOHC (BXPT-10302-SP)

Upgrade your B-series engine's valvetrain with the BLOX Racing performance valve spring. Designed for the Honda/Acura B18A, B18B, and B20 DOHC engines, this performance spring provides increased seat pressure and open pressure over the factory spring — improving valvetrain stability at high RPM and supporting performance camshaft upgrades on B18A/B and B20 builds.

Note: Price is per single spring. Order the quantity required for your application — a full set requires 16 springs (8 intake, 8 exhaust) for a 4-cylinder B-series engine.

Key Features:

• Performance valve spring for B18A, B18B, and B20 DOHC
• Increased seat and open pressure over factory springs
• Improved valvetrain stability at high RPM
• Compatible with performance camshaft upgrades
• BLOX Racing quality and engineering
• Sold individually

Performance Benefits:

• Increased Seat Pressure: Higher closed pressure keeps valves firmly seated, reducing valve float risk at high RPM
• Increased Open Pressure: Greater open pressure ensures valves follow cam lobe profile accurately at high RPM
• Valvetrain Stability: Reduces valve float and valvetrain instability that limits rev ceiling on stock springs
• Cam Upgrade Compatible: Higher spring rates support performance camshafts with increased lift and duration
• High-RPM Capability: Extends the reliable rev range of B18A/B and B20 builds

Specifications:

• Brand: BLOX Racing
• Part Number: BXPT-10302-SP
• Product: Performance Valve Spring
• Application: Honda/Acura B18A, B18B, B20 DOHC
• Quantity: Single spring (1x)
• Weight: 1.0 lb (per spring)
• Barcode: BXPT-10302-SP

Fitment Information:

• Honda/Acura B18A — 1.8L DOHC non-VTEC (Acura Integra RS/LS/GS 1990-1993)
• Honda/Acura B18B — 1.8L DOHC non-VTEC (Acura Integra RS/LS/GS 1994-2001)
• Honda B20B / B20Z — 2.0L DOHC non-VTEC (Honda CR-V 1997-2001, Orthia, Stepwgn)
• Common B20 VTEC swap applications: B20 block with B16/B18C VTEC head — verify spring compatibility with your specific VTEC head
• Note: Verify spring dimensions (free length, seat pressure, open pressure, coil bind height) are compatible with your specific camshaft and retainer combination before ordering
• Note: Not for B16, B18C (VTEC), or other B-series variants without confirming compatibility
• Installation: Professional installation required — valve spring replacement requires cylinder head removal or a valve spring compressor tool

What's Included:

• 1x BLOX Racing performance valve spring (BXPT-10302-SP)
• Note: A complete B-series 4-cylinder engine requires 16 springs total (8 intake, 8 exhaust) — order 16 for a full set
• Note: Valve spring retainers and locks (keepers) sold separately — upgrade retainers recommended when installing performance springs

Installation Notes:

• Professional installation recommended
• Valve spring replacement can be performed with the head on the engine using a valve spring compressor tool, or with the head removed
• Verify piston-to-valve clearance if installing with performance camshafts
• Check coil bind clearance with your specific camshaft lift before installation
• Replace valve stem seals at time of spring replacement
• Verify valve spring retainer and lock (keeper) compatibility with new springs

What is Valve Float — and Why Springs Matter:

Valve float occurs when the engine is revving so quickly that the valve spring cannot close the valve fast enough to follow the cam lobe's closing ramp. At the moment of float, the valve is partially open when it should be closed — allowing combustion gases to escape past the valve seat, reducing compression and power, and potentially causing valve-to-piston contact on high-compression or high-lift cam builds. Factory valve springs are designed for the stock rev limit and cam profile. As RPM increases beyond the factory limit, or when performance camshafts with higher lift and faster opening/closing ramps are installed, the factory springs may not provide enough force to keep the valves under control. Performance valve springs with higher seat and open pressures extend the reliable rev range and support the faster valve motion demanded by performance camshafts.

B18A/B — Non-VTEC B-Series Context:

The B18A and B18B are Honda's 1.8L DOHC non-VTEC engines, used in the Acura Integra RS, LS, and GS from 1990-2001. While lacking the VTEC variable valve timing of the B18C, the B18A/B is a popular platform for naturally aspirated and forced induction builds due to its strong bottom end, wide aftermarket support, and compatibility with VTEC head swaps. Performance valve springs are a common upgrade on B18A/B builds running performance camshafts or targeting a higher rev ceiling than the factory springs support.

B20 — The B20 VTEC Build Platform:

The B20B and B20Z are Honda's 2.0L DOHC non-VTEC engines, used in the Honda CR-V (1997-2001) and other Honda models. The B20 is most famous in the performance community as the basis for the "B20 VTEC" build — pairing the B20's larger 2.0L displacement and stronger bottom end with a VTEC cylinder head (typically from a B16B, B18C, or B16A) to create an engine that combines displacement with VTEC's high-RPM power delivery. The BLOX BXPT-10302-SP spring is designed for the B20's non-VTEC head — if building a B20 VTEC, verify spring compatibility with your specific VTEC head's spring seat dimensions and retainer configuration.

Spring Rate Selection — Matching Springs to Camshafts:

When selecting performance valve springs, it is important to match the spring's seat pressure, open pressure, and coil bind height to your specific camshaft's lift and duration specifications. A spring that is too soft will not control the valve adequately at high RPM with an aggressive cam profile. A spring that is too stiff will increase valvetrain wear and may require upgraded retainers and rocker arms to handle the increased load. BLOX Racing's BXPT-10302-SP is designed for performance B18A/B and B20 applications — verify the spring specifications are appropriate for your specific camshaft before ordering. Consult your camshaft manufacturer's recommended spring specifications for guidance.

Upgrade Retainers:

When installing performance valve springs, it is strongly recommended to upgrade the valve spring retainers at the same time. Factory retainers are made from stamped steel and are designed for the load of factory springs. Performance springs with higher seat and open pressures place greater load on the retainers, and factory retainers may not provide adequate strength or the correct geometry for performance springs. Titanium or chromoly steel retainers provide the strength and weight reduction needed for high-RPM valvetrain performance. BLOX Racing and other manufacturers offer compatible retainers for B-series applications.

Why BLOX Racing?

BLOX Racing is a respected manufacturer of Honda and Acura performance parts, known for their quality construction and correct fitment for B-series, K-series, and other Honda platforms. Their valvetrain components are trusted by Honda enthusiasts worldwide for reliable performance at a competitive price point. BLOX Racing's focus on Honda/Acura applications ensures their valve springs are engineered to the correct specifications for B18A/B and B20 builds.

Perfect For:

• Acura Integra RS/LS/GS B18A and B18B builds running performance camshafts
• Honda CR-V B20 builds wanting performance valve springs for higher RPM operation
• B20 VTEC builds — verify compatibility with your specific VTEC head before ordering
• B18A/B builds targeting a higher rev ceiling than factory springs support
• Anyone replacing worn factory valve springs on a B18A, B18B, or B20 with a performance upgrade

Perfect For: Honda/Acura B18A, B18B, and B20 DOHC builds requiring BLOX Racing performance valve springs for improved valvetrain stability, higher RPM capability, and performance camshaft support.

Pro Tip: Replace valve stem seals at the same time as the springs — if you're already in the head doing the springs, the incremental cost and time to replace the seals is minimal, and worn valve stem seals cause oil consumption and fouled spark plugs that will require the same disassembly to fix later.

Sold Individually — Order 16 for Full Set: B18A, B18B, B20 DOHC. Verify spring specs match your camshaft. Upgrade retainers recommended. Replace valve stem seals at same time. Professional installation recommended.

Upgrade your B18A/B or B20 valvetrain with BLOX Racing performance springs — increased seat and open pressure, improved high-RPM stability, performance cam compatible.