The Mitsubishi Saturn or 4G3 engine is series of straight-4 internal combustion engines introduced by Mitsubishi Motors in 1969, along with the Astron, Orion, and Sirius. Displacement ranges from 1.2 L to 1.8 L.

4G30

The 4G30 displaces 1.3 L (1,289 cc). It is an 8-valve SOHC design with an aluminium head and iron block. The engine has five main bearings. Power was 87 hp.

Bore x Stroke: 73.0 x 77.0 mm

Applications:

• 1969.12-1971.09 Mitsubishi Galant A I (A51)

4G31

The 4G31 displaces 1.5 L (1,499 cc). It is an 8-valve SOHC design with an aluminium head and iron block. The engine has five main bearings. Power was 95-105 hp depending on which carburetor combo was used.

Bore x Stroke: 74.5 x 86.0 mm

Applications:

• 1969.12-1971.09 Mitsubishi Galant A II, A III (A52)

4G32

The 4G32 displaces 1.6 L (1,597 cc). It is an 8-valve SOHC design with an aluminium head and iron block. The engine has five main bearings, a cross flow head and a single down draught carburetor. Firing order is 1-3-4-2. The GSR versions used two twin-barrel Mikuni-built Solex carburetors for a total of 110 hp (SAE).

4G32 ECI engine in a Mitsubishi Mirage

A version of the 4G32 engine was made with a DOHC 8 valve cylinder head, and fitted with two twin choke 40mm Solex sidedraught carburettors. A version with an early iteration of Mitsubishi's MCA lean-burn system (MCA-IIB), fulfilling the Japanese exhaust regulations for 1975 (50年), was called G32A. Those with the later, cleaner yet, "MCA-Jet" system were called G32B. Later, the G32B also came in a fuel injected, turbocharged model.

Bore x Stroke: 76.9 x 86.0 mm (3.03" x 3.39")

Applications:

• Mitsubishi Celeste
• Mitsubishi Galant
• Mitsubishi L300
• Mitsubishi Lancer
• Mitsubishi Sapporo
• Mitsubishi Sigma
• Mitsubishi Cordia
• Mitsubishi Tredia
• Mitsubishi Mirage
• Dodge Colt
• Eagle Vista Turbo
• Hyundai Pony
• Hyundai Stellar
• Mazda Familia
• Plymouth Arrow

4G33

The 4G33 displaces 1.4 L (1,439 cc) from a 73.0 x 86.0 mm bore and stroke. There was also an MCA-Jet equipped G33B developed to fulfill the 1978 (53年) Japanese emissions regulations.

Applications:

• Mitsubishi Celeste
• 1979.06-1989.01 Mitsubishi Delica
• Mitsubishi Galant
• 1977-1979 Mitsubishi Lancer
• Hyundai Pony
• Hyundai Stellar
• Plymouth Arrow

4G35

The 4G35 displaces 1.7 L (1,686 cc). It is an 8-valve SOHC design with an aluminium head and iron block. The engine has five main bearings. Power was 105-115 hp depending on which carburetor combo was used.

Bore x Stroke: 79.0 x 86.0 mm

Applications:

• 1972.01-1973.06 Mitsubishi Galant GS (A55)
• 1972-1976 Mitsubishi Galant GTO (A55)

4G36

The 4G36 displaces 1.2 L (1,238 cc). 73.0 x 74.0 mm bore and stroke.

Applications:

• Mitsubishi Celeste
• Mitsubishi Colt
• Mitsubishi Lancer

4G37

The 8-valve SOHC 4G37 displaces 1.8 L (1,755 cc).

Bore x Stroke: 80.6mm x 86.0mm(3.17in x 3.39in)

Compression Ratio: 9.5:1

Applications:

• Mitsubishi Chariot/Space Wagon 1983-91
• Mitsubishi Cordia
• Mitsubishi Galant
• Mitsubishi Eclipse 1990-1994
• Mitsubishi Lancer/Lancer Fiore/Mirage - 4WD Station wagons only

By other brands:

• Eagle Talon DL 1993-1994
• Plymouth Laser 1990-1994

6G34

The 6G34, referred to by Mitsubishi as the Saturn 6, is a 12-valve SOHC straight-6 of 2.0 L (1,994 cc) displacement.

The 6G34 was used only in the Mitsubishi Debonair Executive from September 1970 to June 1976, and saw very limited production. Effectively, the design was that of the standard Saturn four-cylinder block with two additional cylinders grafted on.

Applications:

• Mitsubishi Debonair 1970.09-1976.06 (Japan only)

See also

• List of Mitsubishi engines

• "Engine Epic Part 8 - Mitsubishi Engines", Michael Knowling, Autospeed, issue 48, 21 September 1999