Positioning:
The Mazda R100 was a pioneering compact sports coupe that introduced the rotary engine to a wider audience, competing with small European sports cars and domestic performance coupes.
Competitors:
Datsun 240Z, Toyota Corolla Levin/Sprinter Trueno (early generations), Alfa Romeo Giulia GT, Ford Capri.
Engine Type:
Unique 2-rotor (10A) Wankel rotary engine, offering a compact, high-revving, and smooth power delivery.
Design:
Distinctive coupe styling with clean lines, sporty proportions, and often a characteristic 'bubble' rear window.
Driving Experience:
Known for its nimble handling, lightweight feel, and the unique sound and acceleration characteristics of the rotary engine.
Usefulness:
Essential for owners and mechanics maintaining the iconic R100, providing crucial technical data and procedures for preserving this unique vehicle.
Engine:
Rotary Engine (10A), including apex seals, rotor housing, rotor, eccentric shaft, lubrication, cooling, and combustion.
Lubricating System:
Oil pump, oil filter, oil passages, oil pressure testing, and oil type specifications.
Cooling System:
Radiator, water pump, thermostat, coolant hoses, coolant type and capacity, and system pressure testing.
Fuel System:
Carburetor (likely Hitachi or Mikuni side-draft), fuel pump, fuel filter, fuel lines, and emissions control components (if applicable).
Electrical System:
Ignition system (distributor, coil, spark plugs), starting system (starter motor, solenoid), charging system (alternator, regulator), lighting, instrumentation, wiring diagrams, and component testing.
Clutch:
Clutch disc, pressure plate, release bearing, clutch pedal adjustment, hydraulic system (if applicable), and removal/installation.
Transmission:
Manual transmission (likely 4-speed or 5-speed), gear lubrication, internal components, shift linkage, and removal/installation.
Propeller Shaft:
Driveshaft, universal joints, balancing, and inspection.
Rear Axle:
Differential, axle shafts, bearings, and fluid specifications.
Suspension:
Front and rear suspension components (springs, shock absorbers, control arms, ball joints, bushings), alignment specifications, and replacement procedures.
Steering:
Steering box, tie rods, steering column, linkage, and adjustment procedures.
Brakes:
Front and rear brake systems (drum or disc), master cylinder, wheel cylinders, brake lines, pads/shoes, hydraulic fluid specifications, bleeding procedures, and parking brake.
Body And Trim:
Body panel repair, door mechanisms, window mechanisms, interior trim, and weather stripping.
Chassis And Frame:
Frame inspection, rust repair, and structural components.
Heating And Air Conditioning:
Heater core, blower motor, ducting (if factory AC equipped).
Emissions Control:
Early emissions systems, PCV valve, air injection (if equipped).
Maintenance:
Routine checks, fluid changes, filter replacements, lubrication points, spark plug replacement, and ignition timing adjustment.
Troubleshooting:
Diagnostic charts, symptom-based troubleshooting for engine performance, electrical issues, and mechanical failures.
Repair:
Step-by-step instructions for component removal, disassembly, inspection, repair, reassembly, and installation.
Overhaul:
Detailed instructions for complete engine, transmission, and differential rebuilds.
Adjustment:
Carburetor tuning, ignition timing, clutch pedal, brakes, and suspension alignment.
Wiring Diagrams:
Comprehensive electrical schematics for all vehicle systems.
Torques Specifications:
Torque values for critical fasteners across all vehicle systems.
Depth:
Comprehensive and detailed, suitable for professional mechanics and experienced DIY enthusiasts.
Diagnostics:
Advanced diagnostic procedures, including electrical testing, compression testing (adapted for rotary), and visual inspections.
Rebuild Procedures:
Full rebuild procedures for major mechanical components like the rotary engine and transmission.
Engine Type:
Mazda 10A (Wankel Rotary)
Displacement:
984 cc (equivalent to approx. 1.0L, but rotary displacement is calculated differently)
Configuration:
Two-rotor, naturally aspirated
Horsepower:
Approximately 100-110 hp (net, depending on market and tuning)
Torque:
Approximately 100-110 lb-ft (net, depending on market and tuning)
Redline:
Typically around 6,000-7,000 RPM
Compression Ratio:
Typically around 9.4:1 to 9.8:1 (rotary specific) - actual effective compression is different from piston engines.
Carburetor:
Single Hitachi or Mikuni side-draft downdraft carburetor (e.g., 40mm or 45mm).
Fuel Type:
Unleaded gasoline (premium recommended for optimal performance and longevity, though leaded was common when new).
Oil Type:
API SG or higher, SAE 10W-30 or 20W-50 (refer to manual for exact specification). Rotary engines often require specific oil properties.
Oil Capacity:
Approximately 4-5 US quarts (refer to manual for exact capacity and filter refill).
Coolant Type:
Ethylene glycol-based coolant (typically 50/50 mix with distilled water).
Oil Change:
Every 3,000-5,000 miles or 6 months (refer to manual for exact interval and oil type).
Spark Plugs:
Inspect at 15,000 miles, replace as needed (specific plug types for rotary engines). Refer to manual for correct part numbers and gap.
Air Filter:
Inspect every 6 months or 7,500 miles, replace as needed.
Fuel Filter:
Replace as needed, typically every 15,000-20,000 miles or if symptoms of fuel starvation appear.
Coolant Flush:
Every 2 years or 30,000 miles.
Transmission Fluid:
Check level periodically, change every 30,000-50,000 miles or as recommended in the manual.
Engine Oil Viscosity:
SAE 10W-30 or 20W-50 recommended (verify with manual).
Transmission Fluid Type:
GL-4 or GL-5, SAE 75W-90 or 80W-90 (verify with manual).
Brake Fluid:
DOT 3 or DOT 4 (verify with manual).
Rotary Engine Apex Seals:
Wear and failure of apex seals leading to loss of compression, rough idle, and smoking are common issues with older rotary engines. Proper lubrication and avoiding over-revving are critical.
Oil Consumption:
Rotary engines inherently consume some oil as part of their lubrication system. Excessive consumption can indicate seal wear.
Carburetor Issues:
Aging diaphragms, worn jets, and vacuum leaks in the carburetor can lead to poor running conditions.
Cooling System:
Radiator leaks, water pump seal failure, and degraded hoses can cause overheating.
Ignition System:
Distributor wear, coil failure, and incorrect spark plug types can affect engine performance and starting.
