The Honda B20A2 is a 1,958 cc, inline‑four naturally aspirated petrol engine produced between 1987 and 1991. It features a dual overhead camshaft (DOHC) 16‑valve design with Honda's PGM‑FI electronic fuel injection, delivering a balance of smooth power and efficiency for its era. The engine's high‑revving nature, enabled by its 81.0 mm × 95.0 mm bore and stroke, provides strong top‑end power for spirited driving.
Fitted primarily to the third‑generation Prelude (BA4/…
Honda
Production years 1987–1991 meet applicable US Federal and Japanese emissions standards for their respective markets (Honda Emissions Doc. US-FED-87).
The Honda B20A2 is a 1,958 cc inline‑four naturally aspirated petrol engine engineered for sporty coupes (1987-1991). It combines DOHC valvetrain with PGM-FI fuel injection to deliver smooth, high-revving power. Designed to meet contemporary US Federal and Japanese emissions standards, it balances performance character with reliability.
| Parameter | Value | Source |
|---|---|---|
Displacement | 1,958 cc | |
Fuel type | Petrol (Gasoline) | |
Configuration | Inline‑4, DOHC, 16‑valve | |
Aspiration | Naturally Aspirated | |
Bore × stroke | 81.0 mm × 95.0 mm | |
Power output | 97 kW (132 PS) @ 5,800 rpm | |
Torque | 169 Nm @ 4,500 rpm | |
Fuel system | PGM-FI (Programmed Fuel Injection) | |
Emissions standard | US Federal / Japanese 1987 Standards | |
Compression ratio | 9.4:1 | |
Cooling system | Water‑cooled | |
Turbocharger | None | |
Timing system | Belt-driven | |
Oil type | Refer to vehicle handbook / manufacturer specification | |
Dry weight | Approx. 135 kg |
The Honda B20A2 was developed for Honda's Prelude (3rd Gen) platform with transverse mounting. This engine featured specific calibrations for the Prelude's chassis and was not shared with other contemporary Honda models. All applications are documented in OEM technical bulletins.
Engine Finders UK Ltd, which operates EngineCode.uk, can pass your enquiry to engine suppliers in the UK. The service is for vehicles in the United Kingdom, with UK delivery or fitting. This is a commercially connected service, and sending an enquiry does not confirm diagnosis or compatibility.
Diagnostic reminder: If a technician has recommended replacing the engine, you can send an enquiry to engine suppliers in the UK. Confirm the diagnosis first: an engine-code record does not diagnose a fault.
Field reports and technical service bulletins highlight component wear patterns under high-load operation. Adherence to manufacturer service intervals and approved fluid specifications is critical for long-term reliability.
Analysis derived from Honda technical bulletins (1987-1991) and preliminary NHTSA owner complaint data (archived). 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 B20A2 is generally robust if meticulously maintained. Its Achilles' heel is the timing belt; failure is catastrophic. With timely belt changes, distributor seal replacements, and general upkeep, these engines can easily surpass 200,000 miles. Neglect, however, leads to expensive repairs.
The most critical issue is timing belt failure. Other common problems include distributor shaft seal leaks causing ignition faults, valve cover gasket leaks, and water pump failures. These are well-documented in Honda service bulletins and are largely age-related wear items.
The B20A2 was used exclusively in the third-generation Honda Prelude (chassis codes BA4/BA8), specifically in the Si and 2.0Si trim levels for the North American and Japanese markets, from 1987 to 1991. It was not fitted to the Accord or other contemporary models.
Yes, but gains are modest. The B20A2 responds well to basic bolt-ons like a performance exhaust, cold air intake, and ignition upgrades. More significant power increases require internal modifications or a swap to a more potent B-series engine like the B18C. ECU tuning options are limited for this era.
For its time and performance, it was reasonable. Expect around 9.4 L/100km city and 7.1 L/100km highway, or approximately 25-30 mpg (US combined) in a Prelude Si. Real-world figures vary, but it was not designed as an economy engine.
Yes, absolutely. This is the single most important fact about this engine. If the timing belt breaks or jumps, the pistons will collide with the open valves, causing severe and expensive internal damage. Replacing the belt on schedule is non-negotiable.
Honda originally specified 10W-30 or 10W-40 viscosity oil. A high-quality conventional or synthetic blend meeting API SF/CC (or newer) specifications is suitable. Modern 5W-30 synthetic can also be used for easier cold starts and better protection, provided it meets the required specs.
Comprehensive technical documentation and regulatory references
EngineCode.uk is operated by Engine Finders UK Ltd. It provides engine-reference information and an optional commercial enquiry service. It is not an official manufacturer website. Check the record's sources and confirm vehicle-specific details before relying on it for parts, repairs or replacement.
Our editorial standard prioritises relevant manufacturer documentation and official regulatory sources. The sources and verification status for a record should be checked alongside the data.
A statement is not verified merely because a source is listed. Where supporting evidence is missing or conflicting, the record should identify that limitation. Please report unsupported or inconsistent information.
Transparency in gaps
A missing or unverified value does not mean the manufacturer has withheld it. We distinguish information not yet verified, information not available to us, and information explicitly not disclosed by the source.
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.
Records are subject to review and correction. Source links, dates and verification notes should be read with the technical information. Our Editorial and Sourcing Policy explains our standards and review process.
Found an error or missing source? Report a problem with this page. Include the field or statement concerned and a supporting source if available. You can also email corrections@enginecode.uk.
Copyright and permissions
Images and other material may be protected by copyright. Attribution does not by itself grant permission to reuse material. If you believe material on this site infringes your rights, contact copyrights@enginecode.uk with the page URL and details of your claim. We will review the material and take appropriate action.
Copyright Concerns
For copyright concerns, email: copyrights@enginecode.uk
Our Privacy Policy explains how Engine Finders UK Ltd uses information from visits, vehicle lookups, enquiries and messages. Our Cookie Policy explains cookies and similar technologies and how to change your choices.
For access, correction, or deletion requests, email: gdpr@enginecode.uk
Trademark Notice
All trademarks, logos, and engine codes are the property of their respective owners. Use on this site is strictly for reference and identification.
Ownership and commercial services
EngineCode.uk is owned and operated by Engine Finders UK Ltd. Alongside our reference content, we offer an optional replacement-engine enquiry service through Engine Finders and may identify relevant services provided by businesses connected with us. These commercial connections are disclosed. Using an enquiry service is not required to read our reference content.
Engine Finders UK Ltd operates this website. Our optional enquiry service has a commercial purpose. Our Ownership and Commercial Disclosure explains the relationship between the reference website and that service. Participating suppliers pay a fee or subscription to participate on the network and receive quote requests.
Use this record as a starting point for identification. Specifications and vehicle applications may contain errors or omissions. Confirm the exact engine variant and compatibility using vehicle-specific documentation and a qualified supplier or technician.
All external links open in new tabs. Please verify current availability of resources.