Market Position:
The Armstrong Siddeley Sapphire 346 was a premium British luxury car, competing with established brands like Rolls-Royce, Bentley, and Jaguar in the post-war era. It offered a blend of performance, comfort, and advanced engineering.
Competitive Analysis:
Competed against vehicles such as the Jaguar Mk VII/Mk VIII, Rover P4, and Daimler Conquest. The Sapphire's unique preselector gearbox and robust engineering set it apart in certain aspects.
Key Features:
Powerful inline-six engine, comfortable and spacious cabin, advanced (for its time) suspension and braking systems, and the availability of the distinctive preselector gearbox.
Manual Utility:
Designed for the official Armstrong Siddeley dealer network, this manual provides the in-depth, authoritative information required for accurate diagnosis and repair, making it invaluable for owners and specialists alike.
Mechanical Systems:
Engine, Engine Lubrication, Carburettor, Decarbonising, Valve Grinding, Centrifugal Clutch, Preselector Gearbox, Synchromesh Gearbox, Automatic Gearbox, Propeller Shaft, Rear Axle, Front Wheel, Suspension, Braking System, Steering Gear, Wheels, Tyres & Jacking
Electrical Systems:
Battery, Dynamo, Starter, Distributor, Control Box, Lamps, Trafficators, Windscreen Wiper, Electric Horns
Other Systems:
Preselector Gear Change Mechanism
Page Count:
Not specified in product information
Manual Type:
Workshop Manual / Service Manual / Repair Manual
Format:
Digital (PDF - requires Adobe Reader)
Engine Mechanical:
Comprehensive coverage of engine disassembly, assembly, tuning, and overhaul, including decarbonising and valve grinding.
Lubrication System:
Detailed procedures for engine lubrication system maintenance, oil change intervals, and troubleshooting.
Fuel System:
In-depth information on the carburettor, including adjustment, cleaning, and overhaul.
Transmission Preselector:
Extensive coverage of the Armstrong Siddeley Preselector gearbox, including operation, maintenance, and repair of the preselector mechanism and gearbox internals.
Transmission Synchromesh:
Detailed guidance on the maintenance and repair of the Synchromesh gearbox and its associated clutch.
Transmission Automatic:
Information pertaining to the Automatic Gearbox, likely referring to the Fluid Flywheel and associated systems of earlier models or optional transmissions.
Drivetrain:
Coverage of the propeller shaft and rear axle, including maintenance and repair of these components.
Suspension Steering Brakes:
Thorough coverage of front wheel assembly, suspension systems, braking system maintenance and repair, and steering gear adjustments.
Wheels Tyres Jacking:
Guidance on wheel and tyre maintenance, including jacking procedures and safety precautions.
Electrical Charging Starting:
Detailed instructions for the battery, dynamo, starter motor, and distributor, including testing and troubleshooting.
Electrical Accessories:
Coverage of control box functions, lighting systems, trafficators (indicators), windscreen wipers, and electric horns.
Routine Maintenance:
Oil changes, lubrication, filter replacements, spark plug checks, and general tune-ups.
Major Overhaul:
Complete engine rebuild, gearbox overhaul, clutch replacement, and brake system relining/repair.
Troubleshooting:
Diagnostic procedures for common faults and issues across all major systems.
Adjustment Calibration:
Carburettor tuning, ignition timing adjustment, brake adjustments, and suspension geometry checks.
Component Replacement:
Step-by-step guides for replacing parts such as gaskets, seals, bearings, brake shoes, and electrical components.
Technical Depth:
Comprehensive, from basic maintenance to complete engine and gearbox rebuilds. Suitable for both amateur and professional mechanics.
Index Type:
Fully Bookmarked & Interactive Index
Engine Type:
Inline 6-cylinder, Overhead Valve (OHV)
Engine Displacement:
3,435 cc (3.4 Litres)
Bore X Stroke:
Not specified in product information, but typically around 83 mm x 105 mm
Compression Ratio:
Typically 7.0:1 or 7.5:1 depending on year and variant.
Horsepower:
Approx. 125-140 bhp at ~4,000 rpm (depending on exact model year and tune).
Torque:
Not specified in product information.
Fuel System Type:
Updraft Carburettor (e.g., Solex or Zenith, depending on year and market).
Engine Block Material:
Cast Iron
Cooling System:
Water-cooled, with fan and thermostat.
Standard Transmission:
Preselector Epicyclic gearbox with manual overdrive control (often referred to as Wilson gearbox).
Optional Transmission:
Synchromesh gearbox and Fluid Flywheel (introduced in later models, often labelled 'Automatic Gearbox' in the manual's scope).
Clutch Type:
Centrifugal clutch for Preselector gearbox, Dry single-plate clutch for Synchromesh gearbox.
Overdrive:
Often equipped with an electrically operated overdrive, providing higher cruising speeds and improved fuel economy.
Gear Ratios:
Not specified in product information.
Wheelbase:
Approximately 105 inches (2,667 mm)
Length:
Approximately 176 inches (4,470 mm)
Width:
Approximately 66 inches (1,676 mm)
Height:
Approximately 60 inches (1,524 mm)
Curb Weight:
Approx. 3,000 - 3,400 lbs (1,360 - 1,542 kg), depending on body style and equipment.
Gross Vehicle Weight:
Not specified in product information.
Infotainment Features:
Basic analogue radio (optional), heater. Focus is on mechanical and electrical systems rather than entertainment.
Driver Assistance Features:
None by modern standards. Driver aids would be limited to the vehicle's inherent driving dynamics and controls.
Connectivity Features:
No electronic connectivity features as understood today.
Electrical Voltage:
6 Volt electrical system.
Engine Oil Change:
Typically every 3,000 miles or 6 months. Refer to manual for specific viscosity recommendations.
Grease Points:
Regular lubrication of chassis grease points is critical. Intervals typically every 1,000-2,000 miles.
Valve Adjustment:
Recommended at specific mileage intervals (e.g., 6,000 miles), crucial for engine performance and longevity.
Engine Oil:
Refer to manual for SAE viscosity grade (e.g., SAE 20W/50 or SAE 30 for older engines). Early models may have used oils with higher ZDDP content for flat-tappet camshafts.
Gearbox Oil:
Specific oil for the Preselector gearbox (e.g., SAE 80 or similar EP gear oil, consult manual). Synchromesh gearbox would use a different specification.
Brake Fluid:
Likely a mineral oil (LHM) or DOT 3/4 fluid depending on the specific brake system components fitted. Manual will specify.
Known Issues:
Preselector gearbox maintenance (especially fluid levels and band adjustments), potential for oil leaks from engine and gearbox seals, carburettor tuning complexity, and wear in suspension bushings.
Part Numbers:
This manual would contain specific part numbers for gaskets, seals, bearings, filters, and other components. These are crucial for accurate sourcing of replacement parts.
Brand Heritage:
Armstrong Siddeley was a long-standing British manufacturer, known for its aircraft engines before entering the automotive industry. The company had a reputation for producing sturdy, well-engineered, and often luxurious vehicles.
Model Evolution:
The Sapphire 346 was a significant model for Armstrong Siddeley, representing a move towards more modern styling and performance. It evolved through two main series, with updates to the engine, transmission options, and styling cues between 1953 and 1958.
Production Period:
1952-1958
Production Location:
Coventry, England
