The Chrysler FirePower 331 is a 5,425 cc, 90‑degree V8 petrol engine produced between 1951 and 1955. It features a single overhead valve (OHV) design with two valves per cylinder and a Carter WCD carburetor, delivering robust, smooth power for luxury sedans of the early 1950s. The forged steel crankshaft and deep — skirt block provided exceptional durability.
Fitted to models such as the Chrysler New Yorker and Imperial, the FirePower 331 was engineered for effortless, hi…
Production years 1951–1955 meet pre-catalyst U.S. Federal Motor Vehicle Safety Standards (FMVSS 101-103). No EPA Tier ratings apply.
The Chrysler FirePower 331 is a 5,425 cc 90-degree V8 petrol engine engineered for full-size luxury sedans (1951-1955). It combines an OHV valvetrain with hemispherical combustion chambers to deliver smooth, high-torque performance. Designed for pre-emissions performance, it prioritizes raw power and durability over fuel economy or modern environmental standards.
| Parameter | Value | Source |
|---|---|---|
Displacement | 5,425 cc | |
Fuel type | Petrol | |
Configuration | 90° V8, OHV, 16-valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 3.81 in × 3.63 in (96.8 mm × 92.1 mm) | |
Power output | 180 hp (134 kW) @ 4,000 rpm | |
Torque | 312 lb-ft (423 Nm) @ 2,400 rpm | |
Fuel system | Single Carter WCD two-barrel carburetor | |
Emissions standard | Pre-catalyst Federal (FMVSS 101-103) | |
Compression ratio | 7.5:1 | |
Cooling system | Water-cooled | |
Turbocharger | None | |
Timing system | Gear-driven camshaft | |
Oil type | Refer to vehicle handbook / manufacturer specification | |
Dry weight | 655 lbs (297 kg) |
The Chrysler FirePower 331 was used exclusively in Chrysler and Imperial luxury sedans with longitudinal mounting. This engine received no platform-specific adaptations or facelift revisions during its production run, ensuring broad parts interchangeability. All applications are documented in OEM factory service manuals.
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.
The FirePower 331's primary reliability consideration is its age and the need for periodic valve adjustments. No factory service bulletins were issued for inherent flaws, as the engine was discontinued before reliability became a major industry focus. Modern operation requires addressing fuel system degradation, ignition wear, and sourcing correct gaskets.
Analysis derived from Chrysler factory service manuals (1951-1955) and SAE historical standards. 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
Aftermarket ECU tuning is common on the FIREPOWER-331 platform, but increasing boost or altering engine parameters accelerates component wear, impacts emissions compliance, and may void vehicle warranties. Any modifications should be evaluated carefully by a qualified specialist.
The most common issues stem from its age: the need for periodic valve adjustments, degradation of fuel system components by modern ethanol-blended gasoline, wear in the original ignition system, and cooling system inefficiencies. These are well-documented in factory service manuals.
The FirePower 331 was used in the Chrysler New Yorker (1951-1955), Chrysler Saratoga (1951-1952), and Imperial (1951-1954). It was the standard V8 engine for these luxury models during those years.
Absolutely. The FirePower 331 is a legendary platform for performance upgrades. Common modifications include higher-lift camshafts, improved cylinder heads, dual four-barrel carburetors, and headers. Many examples exceed 250+ horsepower while retaining streetability.
Fuel economy is very poor by modern standards. Expect 10-14 mpg (city) and 14-18 mpg (highway), or roughly 20.2 L/100km combined. This is typical for a large-displacement, low-compression V8 from the early 1950s.
No. Like virtually all American pushrod V8 engines of its era, the Chrysler FirePower 331 is a non-interference engine. If the timing chain were to fail, the pistons and valves would not collide, preventing catastrophic internal engine damage.
Originally, non-detergent SAE 10W-30 was specified. For modern operation, a high-quality detergent 10W-30 or 10W-40 oil is recommended for better engine protection and cleanliness. Zinc additives are not critical for this flat-tappet design due to its low spring pressures.
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.