The engine has the same architecture as the 68-79 G60, 1979 to 1985 GQ and 1985 to 1996 MQ Nissan Patrol 4 x 4, a version not sold in the US due to crash regulations. The engine came out in the late 60's , and has been updated in the same manner as the 1F and 2F Toyota Landcruiser L6's.
The Patrol engine was similar to the Austin 4 liter truck L6, as NIssan/Datsun used old forlorn British Motor Corporation patents and engines designs, reworked them slightly, and then sold them in early Datsun Bluebirds, Datsun 1200's etc. The OHV Patrol engine was based on that ancient Austin 4 liter truck engine. By about 1990, the engine got an alloy head, fuel injection, and 4.2 liters. In the early versions, it was rare to exceed 16 mpg around the farm. The latest Patrol with a petrol engine gives about 242 hp, and is 4.8 liter OHC I6. The old Zee 280 L28, Cedric RD28, Skyline RB30 and Chrysler/International/Nissan SD33 engines were also found in the frame rails.
Nissan Diesel and gasoline truck engines are for all intents and purposes the most perfect total quality assured engines for every dollar you can spend. Mercedes Benz/Tata/Musso diesle and gasoline truck engines are possibly better, but more expensive.
Engine salesmen here go broke with Nissan engines, because once they are sold, no-one ever comes back for extra parts. Rebuilds are very difficult, as the bore and rings materiel specs and suface texture tollerances are so high that the rings never bed in. There is one grade of piston, with a very narrow tollerance. Thats how Nissan saves money, by making sure nothing ever has to be serviced again. Little wonder little Nissan 3.0 EFI SOHC I6's can start off with little more than 150 hp in a 17 second quarter mile grocery getter, then receive 30 pounds of boost, better valve gear and special cam and end up with 750 hp all on the stock crank, rods, block and head. Then the same sedan does 9 second quarter miles at 150 odd mph. Magic!
