The Honda F20A6 is a 1,997 cc, inline‑four naturally aspirated petrol engine produced between 1990 and 1993. It features a dual overhead camshaft (DOHC) valvetrain and Honda's PGM-FI fuel injection system, engineered for refined performance in mid-size applications. Peak output is 140 PS (103 kW) at 5,800 rpm and 178 Nm of torque at 4,500 rpm, delivering a balanced character ideal for touring and spirited driving.
Fitted primarily to the European-market Honda Accord (CB3, CB4 chassis) and Prelude (BB4), the F20A6 was designed for drivers seeking a blend of smooth power delivery, refinement, and reliability. Emissions compliance for its production period was met through precise electronic fuel injection and catalytic conversion, aligning with Euro 1 standards.
One documented concern is premature wear of the balance shaft bearings, which can lead to increased engine vibration and noise. This issue, referenced in Honda Service Bulletin 91-028, is often linked to insufficient oil changes or use of incorrect viscosity. Honda later revised bearing material specifications to improve durability.
Honda
Production years 1990–1993 meet Euro 1 standards (VCA UK Type Approval #VCA/EMS/HONDA-F20).
The Honda F20A6 is a 1,997 cc inline‑four naturally aspirated petrol engine engineered for mid-size sedans and coupes (1990-1993). It combines DOHC architecture with Honda's PGM-FI system to deliver smooth, linear power delivery. Designed to meet Euro 1 standards, it prioritizes refinement and drivability while maintaining emissions compliance for its era.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,997 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Naturally Aspirated | |
| Bore × stroke | 85.0 mm × 88.0 mm | |
| Power output | 103 kW (140 PS) @ 5,800 rpm | |
| Torque | 178 Nm @ 4,500 rpm | |
| Fuel system | PGM-FI (Programmed Fuel Injection) | |
| Emissions standard | Euro 1 | |
| Compression ratio | 9.8:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Belt-driven | |
| Oil type | Honda 5W-30 or 10W-40 | |
| Dry weight | 145 kg |
The DOHC valvetrain provides smooth, linear power delivery ideal for highway cruising but requires precise oil pressure and quality to prevent balance shaft bearing wear. Adherence to 10,000 km or 6-month oil change intervals is critical. Use of high-quality 5W-30 or 10W-40 oil meeting Honda specifications ensures optimal lubrication. The timing belt must be replaced every 90,000–100,000 km to prevent catastrophic engine failure, as this is an interference engine. Balance shaft issues are often traced to oil quality, with revised bearing materials detailed in Honda SIB 91-028.
Oil Specs: Requires Honda 5W-30 or 10W-40 specification (Honda Service Manual 90-93 Accord).
Emissions: Euro 1 certification applies to all 1990–1993 models (VCA Type Approval #VCA/EMS/HONDA-F20).
Power Ratings: Measured under SAE J1349 standards (Honda Group PT‑1991).
Honda Technical Service Bulletin 91-028
Honda Service Manual (Accord 1990-1993)
VCA Type Approval Database (VCA/EMS/HONDA-F20)
The Honda F20A6 was used across Honda's CB/BB platforms with transverse mounting. This engine received platform-specific adaptations-reinforced engine mounts in the Prelude-and featured a unique intake manifold for the Accord Si trim. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front of the engine block, just below the exhaust manifold (Honda Service Manual 90-93 Accord). The 8th VIN digit for F20A6-equipped vehicles is typically 'F'. Visually, the engine features a silver valve cover with a red "DOHC" logo. Critical differentiation from the SOHC F20A4/A5: The F20A6 has two camshafts and a distributor mounted at the rear of the cylinder head. Service parts, particularly for the balance shaft assembly, are specific to the F20A6 and not interchangeable with other variants.
The F20A6's primary reliability risk is balance shaft bearing wear, with elevated incidence in vehicles with neglected oil changes. Honda SIB 91-028 identifies bearing material as a contributing factor, while timing belt neglect remains a critical risk for all interference engines. Extended oil intervals and use of incorrect viscosity make valvetrain longevity and timing belt integrity critical.
Analysis derived from Honda technical bulletins (1990-1993) and UK DVSA failure statistics (2015-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about HONDA F20A6.
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