The Mitsubishi Neptune or 4G4 engine is a series of iron-block OHV inline-four engines built by Mitsubishi Motors from 1971 to 1979, alongside the Orion, Saturn, Astron, and Sirius. This was to be Mitsubishi's last OHV engine. The inability to clear new passenger car emissions rules for 1978 meant that the Neptunes were replaced by the 4G1 Orion. The Neptune continued to be built until 1979 for commercial vehicles, which suffered less restrictive environmental regulations.
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Overview | |
Manufacturer | Mitsubishi Motors |
Also called | 4G4 |
Production | 1971–1979 |
Layout | |
Configuration | Inline-4 |
Displacement | 1.2–1.4 L (1,188–1,378 cc) |
Cylinder bore | 71 mm (2.8 in) 76.5 mm (3.01 in) |
Piston stroke | 75 mm (2.95 in) |
Block material | Cast iron |
Valvetrain | OHV 2 valves x cyl. |
Compression ratio | 9.0:1 |
Combustion | |
Fuel type | Gasoline |
Cooling system | Water-cooled |
Output | |
Power output | 70–87 PS (51–64 kW; 69–86 hp) |
Torque output | 9.7–11.7 kg⋅m (95–115 N⋅m; 70–85 lb⋅ft) |
Chronology | |
Predecessor | KE engine |
Successor | 4G1 Orion |
Displacement — 1.4 L (1,378 cc)
Bore x Stroke — 76.5 mm × 75 mm (3.01 in × 2.95 in)
Power — 87 PS (64 kW; 86 hp) at 6,000 rpm (Galant FTO)
Torque — 11.7 kg⋅m (115 N⋅m; 85 lb⋅ft) at 4,000 rpm
Displacement — 1.2 L (1,188 cc)
Bore x Stroke — 71 mm × 75 mm (2.80 in × 2.95 in)
Power — 70 PS (51 kW; 69 hp) SAE at 6,000 rpm
Torque — 9.7 kg⋅m (95 N⋅m; 70 lb⋅ft) at 4,000 rpm
Mitsubishi Motors technologies | |
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