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| Mitsubishi Saturn engine | |
|---|---|
 | |
| Overview | |
| Manufacturer | Mitsubishi Motors |
| Also called | 4G3 |
| Production | 1969–1999 |
| Layout | |
| Configuration | Straight-4 &Straight-6 |
| Displacement | 1.2–2.0 L (1,239–1,994 cc) |
| Cylinder bore | 73 mm (2.87 in) 74.5 mm (2.93 in) 77 mm (3.03 in) 79 mm (3.11 in) 80.6 mm (3.17 in) |
| Piston stroke | 74 mm (2.91 in) 77 mm (3.03 in) 86 mm (3.39 in) |
| Cylinder block material | Cast iron |
| Cylinder head material | Aluminium |
| Valvetrain | SOHC &DOHC, 2 valves x cyl. |
| Compression ratio | 9.5:1 |
| Combustion | |
| Turbocharger | On G32B & 4G32T |
| Fuel system | Mikuni-builtSolexcarburetor Central-pointEFI |
| Fuel type | Gasoline |
| Cooling system | Water-cooled |
| Output | |
| Power output | 37–115 hp (28–86 kW) |
TheMitsubishi Saturn or4G3 engine is series ofoverhead camshaft (OHC)straight-fourinternal combustion engines introduced byMitsubishi Motors and saw first service in the 1969Colt Galant. Displacement ranges from 1.2 to 1.8 L (1,239 to 1,755 cc), although there was also a rare 2-litre (1,994 cc)inline-six version built from 1970 until 1976. The early versions havechain driven valvetrain while the later versions arebelt driven and equipped withbalance shafts.
The4G30 displaces 1.3 L (1,289 cc). It is an 8-valveSOHC design with an aluminium head and iron block. The engine has fivemain bearings. Power was 87 hp (65 kW).
Bore x Stroke: 73 mm × 77 mm (2.87 in × 3.03 in)
The4G31 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 (71–78 kW) depending on whichcarburetor combo was used. An updated version with central-pointelectronic fuel injection was installed inMirages andLancers from 1986 on.[1] A version for industrial use has 37 PS (27 kW) at 3000 rpm.[2]
Bore x Stroke: 74.5 mm × 86 mm (2.93 in × 3.39 in)
In 1970, the4G32 was introduced, and it displaces 1.6 L (1,597 cc). It is an eight-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-barrelMikuni-builtSolex carburetors for a total of 110 hp (82 kW) (SAE).
A version with an early iteration ofMitsubishi'sMCAlean-burn system (MCA-IIB), fulfilling the intermediate Japanese exhaust regulations for 1975, was calledG32A. This was built for less than one year, as the new MCA engine arrived in November 1975. Those with the later, cleaner yet, "MCA-Jet" system were calledG32B. Later, the G32B also came in afuel injected,turbocharged model. For competition, a version of the 4G32 engine was made with aDOHC eight-valve cylinder head, and fitted with two twin-choke 40 mm (1.6 in) Solex sidedraft carburettors.
Bore x Stroke: 77 mm × 86 mm (3.03 in × 3.39 in)
Turbocharged version of the 4G32.
The4G3 displaces 1.4 L (1,440 cc) from a 73 mm × 86 mm (2.87 in × 3.39 in) bore and stroke. There was also an MCA-Jet equippedG33B developed to fulfill the 1978 Japanese emissions regulations.
The4G35 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 (78–86 kW) depending on which carburetor combo was used.
Bore x Stroke: 79 mm × 86 mm (3.11 in × 3.39 in)
Applications:
The4G36 displaces 1.2 L (1,239 cc). 73 mm × 74 mm (2.87 in × 2.91 in) bore and stroke.
Applications:
The 8-valveSOHC4G37 displaces 1.8 L (1,755 cc).
Bore x Stroke: 80.6 mm × 86 mm (3.17 in × 3.39 in)
Compression Ratio: 9.5:1
Applications:
By other brands:
The6G34, referred to by Mitsubishi as theSaturn 6, is a 12-valveSOHCstraight-6 of 2.0 L (1,994 cc) displacement.
The 6G34 was used only in theMitsubishi 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 to replace theKE64.
Applications:
