The Honda C30A4 is a 2,977 cc, naturally aspirated V6 petrol engine produced between 1990 and 1998. It features a dual overhead camshaft (DOHC) with 24 valves and Honda's VTEC (Variable Valve Timing and Lift Electronic Control) system. This design prioritized a broad, flat torque curve and high — RPM power, producing 177 kW (240 PS) and 285 Nm of torque.
Fitted exclusively to the first — generation Honda NSX (NA1 chassis), the C30A4 was engineered for exotic supercar perform…
Production years 1990–1998 meet the emissions standards applicable to their respective markets (e.g., US EPA Tier 0/1, Japanese 1988 regulations, EU Directive 91/441/EEC).
The Honda C30A4 is a 2,977 cc V6 naturally aspirated petrol engine engineered for the NSX supercar (1990-1998). It combines DOHC 24-valve architecture with VTEC to deliver a seamless transition from low-end torque to high-RPM power. Designed to meet the emissions standards of its era, it balances exotic performance with Honda's hallmark reliability.
| Parameter | Value | Source |
|---|---|---|
Displacement | 2,977 cc | |
Fuel type | Petrol | |
Configuration | V6, DOHC, 24‑valve | |
Aspiration | Naturally Aspirated | |
Bore × stroke | 90.0 mm × 78.0 mm | |
Power output | 177 kW (240 PS) @ 7,100 rpm | |
Torque | 285 Nm @ 5,400 rpm | |
Fuel system | Honda PGM-FI (Programmed Fuel Injection) | |
Emissions standard | US EPA Tier 0/1, Japanese 1988, EU 91/441/EEC | |
Compression ratio | 10.2:1 | |
Cooling system | Water‑cooled | |
Turbocharger | None | |
Timing system | Belt-driven | |
Oil type | Refer to vehicle handbook / manufacturer specification | |
Dry weight | Not Available |
The Honda C30A4 was used exclusively in Honda's NA1 platform with mid-engine, longitudinal mounting. This engine received minor revisions for the 1994 model year (C30A5), primarily involving the VTEC oil pressure switch and minor ECU updates, creating interchange limits for certain components. All adaptations are documented in OEM technical bulletins.
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The C30A4's primary reliability risk is VTEC oil pressure switch failure, with elevated incidence in high-mileage vehicles. Honda SIB 94-082 documents this issue, while owner reports frequently cite it as a source of drivability complaints. Adherence to the critical 90,000 km timing belt interval is paramount for engine survival.
Analysis derived from Honda technical bulletins (1990-1998) and aggregated owner repair data (1995-2023). Repair procedures should follow manufacturer guidelines.
The most common questions about engine codes, what they mean, how to find them and how this database works
The C30A4 is renowned for its exceptional reliability and durability, often cited as one of the most robust high-performance engines ever made. Its main long-term concerns are the VTEC oil pressure switch and the critical timing belt. With the switch replaced preventatively and the timing belt changed religiously every 90,000 km, these engines can easily surpass 300,000 km with minimal issues.
The most frequent issues are failing VTEC oil pressure switches (causing VTEC malfunctions), neglected timing belt failures (causing engine destruction), worn distributor caps/rotors (causing misfires), and leaking thermostat housings. These are well-documented in Honda service literature and owner communities.
The C30A4 was used exclusively in the first-generation Honda NSX (NA1 chassis) from 1990 to 1998. It was the standard engine for all variants of the NA1 NSX during this period.
Yes, it responds very well to tuning. Basic modifications like a performance exhaust, intake, and ECU chip can yield significant gains. The engine's high-compression, DOHC VTEC design is inherently strong. More serious builds can involve head porting, cams, and even forced induction, with the bottom end capable of handling substantial power increases.
As a 3.0L V6 in a supercar, fuel economy is not its forte. Expect around 14.0 L/100km (20 mpg US) in city driving and 9.5 L/100km (30 mpg US) on the highway. Real-world combined figures typically fall between 22-25 mpg US, heavily influenced by driving style.
Yes. The C30A4 is an interference engine. If the timing belt fails, the pistons will collide with the open valves, causing severe internal engine damage. Adhering to the 90,000 km timing belt replacement interval is absolutely critical.
Honda originally specified SAE 5W-30 with an API SH rating. Modern multi-grade oils like 5W-30 or 0W-30 meeting API SN or higher are perfectly suitable and offer better protection. Always use a quality synthetic brand and change it regularly (every 7,500 km).
Comprehensive technical documentation and regulatory references
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Regulatory Stability
EU regulations are referenced using CELEX identifiers for long-term stability.
EUR-Lex
EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
GOV.UK: Vehicle Approval & V5C
UK vehicle approval processes, import rules, and MoT guidance.
DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
Vehicle Certification Agency (VCA)
UK type-approval authority for automotive products.
Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
WLTP and RDE testing procedures for emissions certification.
GOV.UK: Vehicle Approval
UK compliance and certification requirements for imported and modified vehicles.
VCA Certification Portal
Type-approval guidance and documentation.
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