| Nissan FJ engine | |
| Manufacturer: | Nissan Machinery |
| Configuration: | Straight-4 |
| Valvetrain: | DOHC 4 valves x cyl. |
| Block: | Cast Iron |
| Head: | Aluminium |
| Turbocharger: | On some versions |
| Timing: | Timing Chain |
| Compression: | 8.0:1-11.0:1 |
| Fueltype: | Gasoline |
| Fuelsystem: | Carburetor Electronic fuel injection |
| Oilsystem: | Wet sump |
| Coolingsystem: | Water-cooled |
| Bore: | |
| Stroke: | |
| Power: | NaN0NaN0 |
The FJ engine was a series of straight-4 four-valve DOHC 2.0- or 2.4 - litre internal combustion engines produced by Nissan in the 1980s. They were one of the first mass-produced Japanese engines with more than two valves per cylinder, as well as having electronic fuel injection.
The FJ series came in 2.4 L guise as a rally motor for the 240RS and 2.0 L for general production models. A 1.5 L variant was designed and a prototype was built, however it never went into production.
The FJ series has an aluminium head, chain driven cams, and an iron block. It featured large ports, dual valve-springs and a wide angle bucket on shim valve-train design similar to other (later) Nissan twin-cams such as the VG, CA, RB, and KA series DOHC motors as well as the previous S20 straight-6 DOHC motor from the early 1970s GT-R. The FJ20 weighs while the FJ24 weighs . Turbo motors were only available in Japan and New Zealand while the non-turbo variants were available in Japan, Hong-Kong, Australia and Europe. It was discontinued in the mid-1980s due to its prohibitive cost (mainly due to its cast-iron block).
It is acclaimed by some as the forefather of the CA engine. Although the DOHC CA head is similar, this is unlikely, as the SOHC CA head was devised as a lightweight replacement for the L/Z series motors when the FJ first entered production, and the DOHC CA head appeared later when the RB series was released around the same time as the DOHC CA engines. Datsun enthusiasts like to swap FJ engines into L or Z series-powered vehicles. The FJ has similar mounting points to L/Z/KA blocks.
NOTE: These engines were developed before Nissan used the "D" designation for dual overhead camshafts, a practice that would be first used with the CA series of engines in the mid-1980s. The FJ is indeed a DOHC 16 valve design with mechanically actuated cam on bucket follower design. The head is aluminium and the block is iron.
| FJ20E | FJ20ET | FJ24 | |||
| Total displacement | |||||
| Bore × stroke | |||||
| Compression ratio | 9.1:1 | 8.0:1 | 8.5:1 | 11.0:1 | |
| Max power at rpm | 1500NaN0 at 6,000 | 1900NaN0 at 6,400 | 2050NaN0 at 6,400 | 2400NaN0 at 7,200 | |
| Max torque at rpm | at 4,800 | at 4,800 | at 4,400 | at 6,000 | |
| First use | Oct 1981 DR30 Skyline 2000RS | Feb 1983 DR30 Skyline 2000RS-Turbo | Apr 1984 DR30 Skyline 2000RS-Turbo C | 1983 S110 240RS | |
The numerical value is gross mark (engine single purpose crankshaft output).
A part of numerical value is different by Skyline and Silvia/Gazelle.
There is a version of the FJ24 with 2750NaN0.
Distinguished by the "E" for "Electronic Fuel Injection". Maximum output was 1500NaN0.
The FJ20E was installed in the DR30 Skyline RS, as well as the US110 and S12 Gazelle/Silvia RS and GP models.
Distinguished by the "E" for electronic fuel injection, with "T" standing for a turbocharged engine. Maximum output was 1900NaN0 in the R30, and 1850NaN0 in the S12. Boost pressure to achieve this power output was only NaNpsi. Later intercooled versions produced 2050NaN0 with a slight boost increase and smaller turbocharger exhaust housing.
The FJ20ET was installed in the DR30 Skyline RS/RS-X/RS-X Turbo C and S12 Gazelle/Silvia RS-X; Turbo C versions of the DR30 were intercooled, as well as some S12 RS-X trim cars. The intake plenum chamber was shortened in the S12 compared with the DR30 because of the smaller engine bay and thus produced slightly less torque and power. However, the DR30 intake plenum can be fitted to the S12 engine bay with very little clearance. The DR30 FJ20ET also featured a twin scroll exhaust manifold, while the S12 received a smaller log-style turbo manifold due to lack of firewall clearance.
200 or more were produced as a homologation car engine of World Rally Championship at that time according to the Group B regulation. Displacement was expanded to 2340cc, though it was carbureted. The FJ24 was installed in the Nissan 240RS based on the S110 model Silvia. Among 200 total production number, 50 were right-hand drive (RHD), and 150 were left-hand drive, and obtained the Group B recognition of the WRC. 30 were used for the domestic rally championship in the WRC and each country from among the original 200. The number of sales in Japan is uncertain because there was no detailed record, though a small number of people bought the original rally cars. Therefore, development was not done in consideration of domestic exhaust emissions regulations.
Three 240RSs came to Guatemala. Their code numbers were 33D, 16E and 77. They were raced in the Guatemalan and Central American Championships in 1985 and 1986.