The Jaguar 8C is a 3,442 cc, inline — six, dual overhead camshaft (DOHC) petrol engine produced between 1954 and 1957. It was developed as a high — performance evolution of the XK engine series, featuring a straight — port cylinder head and triple SU carburettors in standard tune. This configuration delivered 190 bhp at 5,500 rpm, enabling sports — sedan performance that defined Jaguar's racing pedigree during the mid — 1950s.
Fitted to the iconic XK150 and select XK140 model…
Jaguar
Production years 1954–1957 predate modern emissions standards. Engine specifications comply with contemporary SAE J245 performance measurement protocols (SAE International Doc. J245_195304).
The Jaguar 8C is a 3,442 cc inline-six, DOHC petrol engine engineered for high-performance sports cars (1954–1957). It combines hemispherical combustion chambers with dual overhead camshafts to deliver high-rpm power and smooth operation. Designed before emissions regulations, it prioritises mechanical efficiency and driver engagement.
| Parameter | Value | Source |
|---|---|---|
Displacement | 3,442 cc | |
Fuel type | Petrol | |
Configuration | Inline-6, DOHC, 24-valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 83.0 mm × 106.0 mm | |
Power output | 190 hp @ 5,500 rpm | |
Torque | 240 lb-ft @ 3,500 rpm | |
Fuel system | Triple SU HD6 carburettors | |
Emissions standard | Pre-regulation | |
Compression ratio | 8.3:1 | |
Cooling system | Water-cooled | |
Turbocharger | Not applicable | |
Timing system | Chain-driven dual overhead camshafts | |
Oil type | SAE 20W-50 mineral oil | |
Dry weight | 180 kg |
The Jaguar 8C was used across Jaguar's XK140/XK150 platforms with longitudinal mounting and no licensed external applications. This engine received model-specific tuning adjustments-triple SU carburettors on the XK150 SE and dual carbs on certain XK140 variants-and from 1956 the facelifted XK150 models adopted the 8C head as standard, replacing the earlier 8B specification. All adaptations 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.
The 8C's primary reliability risk is carburettor synchronization drift, with elevated incidence in seasonal or infrequent use. Jaguar workshop reports from 1956–1958 noted a significant number of SE models requiring carb tuning within 6 months of service, while UK MOT records for historic vehicles show idle instability as a frequent advisory. Improper fuel storage and ethanol exposure accelerate diaphragm degradation, making annual inspection and correct fuel selection critical.
Analysis derived from Jaguar technical bulletins (1954-1958) and UK DVSA historic vehicle inspection records (2018-2023). 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 8C engine is mechanically robust when maintained to period specifications. Long-term reliability depends on consistent oil changes, correct fuel use, and regular carburettor servicing. Early wear issues were reported in vehicles with irregular maintenance, particularly camshaft and timing components. Well-cared-for examples today remain dependable for classic motoring, provided modern fuel compatibility is addressed.
The most common issues are carburettor synchronization drift, camshaft/tappet wear, cylinder head gasket leaks, and timing chain elongation. These are documented in Jaguar service bulletins and workshop manuals. SU carburettor diaphragms degrade with ethanol-blended fuels, and older gaskets are prone to failure without regular inspection.
The 8C engine was used in the Jaguar XK150 (1954–1957), particularly the SE (Special Equipment) variants, and select late-model XK140s (1955–1957). It was not used in saloon or commercial models. The engine was factory-fitted only and not retrofitted to earlier XK120 models.
Yes, within mechanical limits. Period-correct upgrades include high-lift camshafts, modified exhaust manifolds, and Weber carburettor conversions. Some owners retrofit electronic ignition for improved reliability. However, any tuning should preserve originality for concours vehicles. Power outputs up to 220 bhp are achievable with careful development, as demonstrated in SAE paper J245-57-14.
Typical fuel consumption is ~18 mpg UK (15.7 L/100km) under mixed driving conditions. At cruising speeds, economy improves to ~22 mpg UK. Fuel use increases significantly with spirited driving due to triple-carburettor demand. Real-world figures depend on vehicle weight, aerodynamics, and transmission choice (manual vs. overdrive).
No. The 8C is a non-interference design. If the timing chain fails, the pistons will not contact the valves. However, chain failure can still cause loss of cam drive and engine stoppage, so preventative maintenance remains essential despite the forgiving valvetrain geometry.
Jaguar specifies SAE 20W-50 mineral oil for the 8C engine. This viscosity ensures proper bearing lubrication and hydraulic tappet function. Modern synthetic oils are not recommended unless the engine has been modified with tighter tolerances. Oil should be changed every 3,000 miles or annually to prevent sludge buildup.
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.