The Mitsubishi Neptune or 4G4 engine is a series of iron-block OHV straight-4 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 emissions rules for 1978 meant that the Neptunes were replaced by the 4G1 Orion.

4G41

Displacement — 1378 cc
Bore — 76.5 mm
Stroke — 75.0 mm
Compression ratio — 9.0:1
Power — 64 kW (87 PS) @ 6,000 rpm
Torque — 115 Nm (85 ft·lbf) @ 4,000 rpm

Applications

• Mitsubishi Galant
• 1971-1973 Mitsubishi Galant FTO
• 1971.10-1979.06 Mitsubishi Delica 75/1400

4G42

Displacement — 1187 cc
Bore — 71.0 mm
Stroke — 75.0 mm
Compression ratio — 9.0:1
Power — 51 kW (70 PS) SAE @ 6,000 rpm
Torque — 95 Nm (9.7 kgm) @ 4,000 rpm

Applications

• 1973.02-1976.10 Mitsubishi Lancer A71

See also

• List of Mitsubishi engines