Mitsubishi Saturn engine


The Mitsubishi Saturn or 4G3 engine is series of overhead camshaft straight-four internal combustion engines introduced by Mitsubishi Motors and saw first service in the 1969 Colt Galant. Displacement ranges from, although there was also a rare inline-six version built from 1970 until 1976. The early versions have chain driven valvetrain while the later versions are belt driven and equipped with balance shafts.

4G30

The 4G30 displaces. It is an 8-valve SOHC design with an aluminium head and iron block. The engine has five main bearings. Power was.
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The 4G31 displaces. It is an 8-valve SOHC design with an aluminium head and iron block. The engine has five main bearings. Power was depending on which carburetor combo was used. An updated version with central-point electronic fuel injection was installed in Mirages and Lancers from 1986 on. A version for industrial use has at 3000 rpm.
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Applications

In 1970, the 4G32 was introduced, and it displaces. 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-barrel Mikuni-built Solex carburetors for a total of .
A version with an early iteration of Mitsubishi's MCA lean-burn system, fulfilling the intermediate Japanese exhaust regulations for 1975, was called G32A. 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 called G32B. Later, the G32B also came in a fuel injected, turbocharged model. For competition, a version of the 4G32 engine was made with a DOHC eight-valve cylinder head, and fitted with two twin-choke Solex sidedraft carburettors.
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Turbocharged version of the 4G32.

4G33

The 4G33 displaces from a bore and stroke. There was also an MCA-Jet equipped G33B developed to fulfill the 1978 Japanese emissions regulations.
The 4G35 displaces. It is an 8-valve SOHC design with an aluminium head and iron block. The engine has five main bearings. Power was depending on which carburetor combo was used.
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The 4G36 displaces. bore and stroke.
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The 8-valve SOHC 4G37 displaces.
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Compression Ratio: 9.5:1
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By other brands:
The 6G34, referred to by Mitsubishi as the Saturn 6, is a 12-valve SOHC straight-6 of 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 to replace the KE64.
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