The Prince G-series engine was the company's only straight-four and straight-six engines which began production in 1955. A number of variations were made, with both OHV and OHC heads. A diesel four-cylinder with 1862 cc was also built, called the D-6. The G series was used in the Skyline, the Laurel, and the Gloria from the 1950s to the early 1970s. Note that, prior to its merger with Prince, Nissan also made a G series of engines. These are unrelated engines and are documented at the Nissan G engine page. The source of the listed information is the corresponding article at Japanese Wikipedia.

Flat-2

In 1956, Prince developed a flat-2 engine, the FG2D, for their DPSK (later CPSK) concept car. It displaced 601 cc and produced 24 hp. The engine suffered excessive vibration and noise issues and was replaced with the FG4C engine.

Flat-4

Prince developed the FG4C, a flat-four displacing 599 cc and producing 38 hp, as a replacement for the FG2D. The FG4C was used in the 1957 CPSK concept.

Straight-4

FG4A-10

1484 cc diameter X stroke: 75x84 mm, OHV

FG4A-20

1484 cc diameter X stroke: 75x84 mm, OHV

FG4A-30

1484 cc diameter X stroke: 75x84 mm, OHV Renamed GA-30 in 1958 Applications:

GA-30

1484 cc diameter X stroke: 75x84 mm, OHV

GA-4

1484 cc diameter X stroke: 75x84 mm, OHV 1959 improvement on the GA-30; also known as FG4A-40 Applications:

GB-30

1862 cc diameter X stroke: 84x84 mm, OHV Also known as FG4B-30 Applications:

GB-4

1862 cc diameter X stroke: 84x84 mm, OHV Also known as FG4B-40 Applications:

G-1

The Prince G-1 was the improved GA-4, and was rated at 1.5 L, but displaced 1484 cc thanks to an entirely different 75 by bore and stroke. This undersquare arrangement was similar to the designs Nissan licensed from Austin Motor Company, though this is probably coincidental. This engine was also an OHV design and power output was similar to the Nissan G at 73 hp and 12 kgm. Applications:

G-2

The G-2 is a 1862 cc version used by Prince. Bore and stroke were square at 84 mm, and output was 96 hp and 15.7 kgm with a 2 barrel carburetor. It was an improved version of the GB-4 and was introduced in 1962 and was installed in the S40 series Prince Gloria as well as the Clipper and Super Miler commercial vehicles. The G-2 was an OHV design. Applications:

G-15

The SOHC G-15 was a 1483 cc engine produced in 1967 for the Skyline. Bore and stroke was 82x70 mm. With a 2 barrel carburetor equipped, the engine produced 94 hp and 13.3 kgm. With a crossflow cylinder head, a V-shaped canted valve arrangement and a multi-spherical combustion chamber design, the G-15 was the most technologically advanced Japanese car engine of its day, eclipsing even Nissan's L series engine in their design. The Nissan G engine was not related to the Prince engine; the Nissan version was OHV and slightly smaller displacement. Applications:

G-16

1593 cc inside diameter x stroke: 85x70.2 mm mmin, SOHC The G-15 was bored out 3 mm to form the G-16. Adapting the engine to more stringent US emissions was deemed too expensive, and it was replaced by the L16 engine in 1975. Applications:

G-18

The G-18 was a 1815 cc. Its 85 mm bore was the largest in the range (except for the G20 mentioned in the next paragraph), and the 80 mm stroke gave it good oversquare dimensions. It was an SOHC cross flow cylinder head design like the G-15 and produced 105 hp and 15.9 kgm. This engine was discontinued in 1975 due to tightening emission regulations and replaced with the L18. Applications:

G-20

1990 cc inside diameter x stroke: 89x80 mm, SOHC Twin Barrel single Carburetor Twin SU carburetor regular gasoline Twin SU carburetor high octane gasoline This engine was only used in the 1968-1975 C30 & C130 Laurel, and was discontinued in 1975 due to tightening emission regulations.

Straight-6

Prince used a straight-6 version of the G family in their famous Skyline cars. All of the Prince straight-6 engines used single overhead cam heads. Engine displacement was kept below 2000cc to limit the amount of Road tax to be paid yearly in addition to other Japanese Government mandated expenses.

G-7

The G-7 is a straight-6 version displacing 1988 cc. It was the engine of the GT-model Prince Skylines and was an OHC engine unlike the mainly-OHV family that spawned it. Bore and stroke were square at 75 mm and power output varied with the carburetor equipped. Plain versions featured a 2 barrel carb and 8.8:1 for 106 hp and 16 kgm, while the 1965 Skyline GT-B used 3 twin-barrel Weber carburetors and 9.3:1 compression for 127 hp and 17 kgm. It was influenced by the Mercedes-Benz M180 straight six engine. The intake and exhaust manifolds are on the left side of the engine because Japanese drivers sit on the right side and the steering column would interfere, while the Mercedes-Benz engine places the intake and exhaust on the right side due to left hand driving conditions. Applications:

G7B-R

1988 cc inside diameter x stroke: 75x75 mm An improvement on the G7 using a cross-flow cylinder head and was converted into racing use during 1965 - 1966 in the S54 Skyline GT used for racing. Was not commercially available.

GR-8

1996 cc inside diameter x stroke: 82x63 mm, DOHC Racing engine used in the Prince R380 and Nissan R380-II, based on the G7 engine. It used 4 valves per cylinders and DOHC, used 3 Weber carburetors model 42DCOE-18, producing a claimed 200 hp for the R380 and 220 hp for the R380-II. The GR-8 used in the R380-III featured mechanical fuel injection. The Nissan S20 engine was derived from the GR-8.

G-11

The G-11 is another straight-6 OHC version, displacing 2494 cc. Bore was up to 84 mm like the G-2 4-cylinder, while stroke remained at 75 mm as on the G-7. Power output with a 4 barrel carburetor was 134 hp with 19.9 kgm of torque. Applications: