🏷️ Basic Information Identification Make: Porsche Model: 928 Product Type: Conversion Instructions Codes Engine Code Original: M28/15 (early 16V), M28/41 (late 16V), M28/44 (4V, 16V), M28/50 (early 32V), M28/52 (late 32V) Conversion Target Engine: 32 Valve (4 Valves per Cylinder) 👋 Introduction Market Position Product Category: Performance Enhancement / Engine Modification Target Audience: Porsche 928 owners seeking to significantly increase engine power and performance through a V8 4-valve per cylinder conversion. Competitive Analysis Alternatives: Purchasing a factory 32-valve 928 (GTS), aftermarket performance heads, or other engine swap options. Key Features Performance Gain Potential: Significant increase in horsepower and torque over 16-valve models due to improved volumetric efficiency. Technical Focus: Detailed, step-by-step instructions for a complex engine modification. 📋 Manual Details Coverage Areas Manual Title: PORSCHE 928 16V to 32V GEAR CONVERSION INSTRUCTIONS Primary Application: Modification of Porsche 928 16-valve engines to 32-valve specification. Page Count Estimated Page Count: Variable (typical conversion guides range from 20-60 pages, depending on detail level and included diagrams). Manual Type Manual Type: Technical Conversion Guide / Modification Manual Language Language: English Format Format: Likely Digital (PDF) or Print-on-Demand. Specific format not explicitly stated but common for specialized guides. 📖 Manual Coverage Systems Covered Engine Mechanical: Cylinder head modification, valve train conversion, camshaft installation, piston selection, cylinder block preparation (if applicable for 4-valve heads). Engine Management: Fuel injection system adaptation, ignition system considerations for 4 valves per cylinder, ECU remapping or replacement recommendations. Procedures Included Disassembly Assembly: Detailed steps for disassembling the 16-valve cylinder heads and assembling the 32-valve components. Component Installation: Instructions for installing new camshafts, valves, valve springs, retainers, and potentially piston crowns or connecting rods. Timing Procedures: Specific instructions for setting the timing of the new 4-valve cylinder heads and camshafts. Component Identification: Identification of necessary 32-valve components (cylinder heads, camshafts, valves, pistons, intake manifold, etc.). Technical Depth Depth: Advanced mechanical and engine management modification. Assumes a skilled mechanic with prior Porsche 928 experience. Diagnostic Focus: Troubleshooting potential issues arising from the conversion process, such as incorrect timing, fueling, or ignition. Modification Level: Detailed instructions for a significant engine hardware modification, bridging the gap between OEM 16V and 32V engines. 📊 Manual Specifications File Format File Format: PDF (likely, if digital) Print Quality Print Quality: High resolution diagrams and text (expected for technical guides). Binding Type Binding Type: Not Applicable (if PDF). If printed, likely comb or spiral bound for ease of use in a workshop environment. Paper Type Paper Type: Not Applicable (if PDF). If printed, standard or glossy paper for diagrams. Completeness Manual Completeness: Specific to the 16V to 32V head conversion. Does not cover general service or overhaul of the entire vehicle. ⚙️ Engine Specifications Primary Engine Engine Family: Porsche V8 Displacement Original: 4.5L, 4.7L, 5.0L (depending on 928 model year and engine variant). Valvetrain Original: SOHC, 2 valves per cylinder (16 valves total). Valvetrain Conversion Target: DOHC, 4 valves per cylinder (32 valves total). Engine Configuration: V8 Performance Horsepower Gain Estimated: Potential for 300-400+ HP depending on the specific conversion kit, supporting modifications, and tuning (factory 16V models ranged from ~240-300 HP). Torque Gain Estimated: Significant increase in torque across the rev range. Fuel System Original Fuel System: Bosch L-Jetronic, then Bosch Motronic fuel injection. Conversion Fuel System Considerations: May require larger fuel injectors, upgraded fuel pump, and potentially a different fuel pressure regulator to support the increased air intake. 🔧 Transmission Standard Transmission Options: Porsche transaxle system (Rear-mounted transmission and differential). Transmission Types: 4-speed Automatic (AWS - Automatic Transmission) or 5-speed Manual (G-Series). Optional Gear Ratio Considerations: The increased power output from the 32-valve engine may warrant consideration of different final drive or gear ratios for optimal performance. Features Clutch Requirements: Upgraded clutch may be necessary to handle the increased torque, especially with a manual transmission. 📐 Dimensions Exterior Wheelbase: 2550 mm (100.4 in) Length: 4650-4750 mm (183.1-187.0 in), varies by model year. Width: 1775-1835 mm (69.9-72.2 in), varies by model year. Height: 1280-1320 mm (50.4-52.0 in), varies by model year. Weights Curb Weight: Approximately 1550-1700 kg (3417-3748 lbs), varies by model year and transmission. 🛡️ Safety Features Ratings Historical Safety Features: Early 928s featured robust chassis design, crumple zones. Later models included airbags and ABS. Specific ratings are less relevant for a modification guide. Active Features Braking System: Originally 4-wheel disc brakes. Conversion may not directly impact brake system but increased performance requires ensuring brake system is in excellent condition. ABS standard on later models. Passive Features Chassis Integrity: The conversion does not typically alter the chassis structure, preserving its original safety characteristics. 💡 Technology Features Infotainment Original Infotainment: Early models had basic radio/cassette players. Later models featured more integrated sound systems, and optional CD players. Some markets received basic trip computers. Driver Assistance Original Driver Assistance: ABS (Anti-lock Braking System) became standard on later models. Some...