🏷️ Basic Information

Make:

Porsche

Model:

911

Year:

1973

Chassis Code:

911 / 911G Series (Early G-Series)

Engine Codes Covered:

2.4L Flat-6 (911/53, 911/57, 911/73, 911/77)

👋 Introduction

Market Segment:

Luxury Sports Car / Grand Tourer

Key Competitors:

Ferrari Dino 246 GT, Jaguar E-Type, Chevrolet Corvette C3, Aston Martin V8.

Unique Selling Points:

Iconic rear-engine layout, legendary handling, build quality, air-cooled flat-six engine sound and performance, timeless design.

Intended User:

Porsche technicians, independent specialists, and knowledgeable DIY enthusiasts working on a 1973 Porsche 911.

Specific Variants:

The manual should cover the base 911, 911 T, 911 E, and 911 S variants for the 1973 model year.

📋 Manual Details

Systems Covered:

Engine, Fuel System, Ignition System, Clutch, Transmission (4-speed manual), Drive Shafts, Suspension (Front & Rear), Steering, Brakes (Front Disc, Rear Disc), Electrical System, Body & Chassis, Interior Trim, Heating & Ventilation, Lubrication, Cooling System, Emission Controls (US models), Wheels & Tires

Body Trim Interior:

Details on interior component removal and installation, seat adjustments, dashboard layout, and trim panel access.

Estimated Page Count:

Approximately 700-900 pages (typical for this era's comprehensive factory manuals)

Diagram Illustration Quality:

Expect high-quality exploded-view diagrams and technical illustrations that clearly depict component relationships and assembly sequences.

Manual Type:

Factory Service Repair Manual

Language:

English

Format:

Likely Print; Digital versions (PDF) may exist from aftermarket sources but original is print.

Manual Type Clarification:

This is a technical service manual, providing repair and maintenance procedures, not an owner's manual (which focuses on operation and basic care) or a parts catalog (which lists part numbers).

📖 Manual Coverage

Engine Mechanical:

Disassembly, assembly, inspection, repair, and overhaul procedures for the 911's air-cooled flat-six engine, including cylinder heads, pistons, connecting rods, crankshaft, camshafts, valve train, oil pump, and cooling system.

Fuel System:

Details on fuel pumps, fuel lines, fuel tank, and particularly the Bosch mechanical fuel injection (MFI) system (CIS was not yet introduced for this year) or Solex carburetors depending on model variant and market.

Ignition System:

Information on distributor, ignition coil, spark plugs, and ignition timing adjustment.

Drivetrain:

Repair and maintenance of the clutch assembly, the 915 5-speed transaxle (although 1973 also offered 4-speed), axle shafts, and final drive.

Suspension Steering:

Front and rear suspension components, shock absorbers, torsion bars, bushings, wheel alignment specifications, steering rack, and steering column.

Brakes:

Hydraulic system, master cylinder, brake lines, calipers, brake pads, rotors, and parking brake adjustments.

Electrical System:

Wiring diagrams, generator/alternator, starter motor, battery, lighting, fuses, relays, instrumentation, and dashboard controls.

Body Chassis:

Body panel removal/installation, chassis lubrication points, door mechanisms, window regulators, and basic bodywork repair considerations.

Heating Ventilation:

Operation and maintenance of the cabin heating system, often relying on heat exchangers fed by engine exhaust or air flaps.

Repair Procedures:

Detailed step-by-step instructions for major component overhauls (engine, transmission), part replacements (e.g., brake calipers, suspension arms), and system repairs.

Maintenance Procedures:

Routine service tasks such as oil changes, spark plug replacement, filter changes, lubrication, and safety checks.

Troubleshooting Diagnostics:

Guides for identifying and rectifying common problems, often including symptom-based diagnostics and specific checks for fuel, ignition, and electrical issues.

Specifications Tolerances:

Crucial data like torque values, clearances, fluid capacities, electrical resistance, and dimensional tolerances required for accurate repairs.

Wiring Diagrams:

Detailed electrical system wiring diagrams for various models and options, crucial for troubleshooting electrical faults.

Depth Of Coverage:

Comprehensive, covering everything from basic adjustments to full engine and transmission rebuilds. Assumes a degree of mechanical aptitude and specialized tools.

Special Tool Requirements:

The manual will likely list and illustrate specific Porsche factory special tools required for certain complex procedures (e.g., engine disassembly, valve adjustments, fuel injection calibration).

📊 Manual Specifications

Digital File Type:

If digital, likely PDF. Original is printed material.

Original Print Quality:

High-quality factory printing on durable paper stock.

Original Binding:

Typically hardcover or robust stapled/stitched binding for factory originals.

Original Paper Type:

Durable, often coated paper stock to resist grease and wear in a workshop environment.

Manual Scope:

Factory original, comprehensive coverage intended for professional technicians. Likely includes exploded views, diagrams, torque specifications, and diagnostic charts.

⚙️ Engine Specifications

Engine Type:

Air-cooled, naturally aspirated, Boxer-6 (Flat-6)

Displacement:

2341 cc (2.3 Liters)

Bore X Stroke:

84.0 mm x 70.4 mm

Compression Ratio:

8.0:1 (approx.)

Horsepower:

130 PS (96 kW; 128 hp) @ 5800 rpm (for 911 / 911 model); 165 PS (121 kW; 163 hp) @ 6500 rpm (for 911 T); 190 PS (140 kW; 187 hp) @ 6500 rpm (for 911 E); 210 PS (154 kW; 207 hp) @ 6200 rpm (for 911 S).

Torque:

189 Nm (139 lb-ft) @ 3500 rpm (for 911 / 911 model); 197 Nm (145 lb-ft) @ 4500 rpm (for 911 T); 207 Nm (153 lb-ft) @ 5000 rpm (for 911 E); 230 Nm (169 lb-ft) @ 5000 rpm (for 911 S).

Fuel Delivery:

Bosch Mechanical Fuel Injection (MFI) for 911 S and E variants; Zenith or Solex carburetors for 911 T (twin dual-throat carburetors).

Fuel Type:

Premium Unleaded Gasoline (Octane rating as specified by Porsche for the era, likely 96 RON / 91 AKI).

Cooling Method:

Forced Air Cooling with Oil Cooling

Oil System:

Dry Sump Lubrication with external oil tank

Engine Codes:

911/53 (2.4L US), 911/57 (2.4L Europe), 911/73 (2.4L CIS for California models – though CIS was more prevalent from 1974), 911/77 (2.4L for other export markets). The manual would detail the differences.

🔧 Transmission

Transmission Type:

Porsche 915 Transaxle (5-speed Manual)

Optional Transmission:

Some early 1973 models may have retained a 4-speed manual transmission, though the 5-speed 915 became standard.

Gear Ratios:

Varies by model variant (e.g., 911 T, E, S), specific ratios would be detailed in the manual.

Transmission Fluid:

Gear Oil API GL-4 or GL-5, viscosity typically 75W-90 or 80W-90. Specific Porsche part numbers and specs would be in the manual.

📐 Dimensions

Wheelbase:

2271 mm (89.4 inches)

Length:

4160 mm (163.8 inches)

Width:

1610 mm (63.4 inches)

Height:

1290 mm (50.8 inches) (approx., varies slightly by model)

Curb Weight:

Approx. 1070–1140 kg (2359–2513 lb) depending on model variant.

Fuel Capacity:

77 liters (20.3 US gallons), with an optional 90-liter (23.8 US gallons) tank.

🛡️ Safety Features

Safety Standards Era:

Designed to meet safety regulations of the early 1970s. Modern crash test ratings do not apply.

Active Safety:

Disc brakes on all four wheels, responsive steering, balanced chassis. Some models might have had optional anti-roll bars.

Passive Safety:

Steel body construction, padded dashboard, three-point seatbelts (standard in many markets by 1973), integrated roll bar in Targa models.

💡 Technology Features

Infotainment System:

Basic analog instrumentation, likely a period-correct radio with AM/FM reception. No integrated infotainment or digital displays.

Driver Assistance Features:

None by modern standards. Focus is on driver engagement and mechanical feedback.

Connectivity Features:

None.

🔧 Maintenance

Oil Change Interval:

Typically every 3,000-5,000 miles (5,000-8,000 km) or annually, with filter change at each interval. The manual will specify.

Major Service Interval:

Valve adjustment and spark plug replacement often recommended around 15,000-20,000 miles (25,000-30,000 km).

Engine Oil Type:

Typically SAE 20W-50 or 10W-40, air-cooled specific oil with high zinc content (ZDDP) is often recommended by specialists. Manual will specify Porsche A40 or equivalent.

Brake Fluid Type:

DOT 3 or DOT 4 hydraulic brake fluid.

Clutch Fluid Type:

Same as brake fluid (DOT 3 or DOT 4).

Engine Oil Capacity:

Approximately 8.0 liters (8.5 US quarts) including oil tank and cooler. Manual will confirm exact capacity and oil filter part number (e.g., Mann W912/1, Mahle KL066).

Common Wear Items:

Valve guides, oil leaks (especially from through-bolt seals and fan shroud), fuel injection system components (MFI pump, lines), clutch release bearing, torsion bar bushings, engine tin wear, heat exchanger corrosion.

Air Cooled Engine Care:

Requires diligent maintenance to prevent overheating and oil consumption issues common to air-cooled designs of this era. Proper oil level and engine tin integrity are critical.

📚 Vehicle History

Brand Origin:

Stuttgart, Germany, founded by Ferdinand Porsche.

911 Generations Covered By Manual:

This manual covers the early 'F-Series' 911 and the very beginning of the 'G-Series' 911. The 1973 model year represented a transition with the introduction of the longer wheelbase and the 2.4L engines, a significant evolution from the original 901/911 platform.

Production Location:

Zuffenhausen, Stuttgart, Germany.

Production Years For This Platform:

The 2.4L engine platform ran from 1972-1973. The G-series chassis itself was introduced in 1974.

🏆 Awards & Recognition

Automotive Excellence Awards:

While specific awards for the 1973 model year are not typically documented in the same way as modern cars, the 911 line consistently received accolades for its performance, engineering, and driving dynamics throughout its history. Considered a benchmark sports car of its era.