Nissan RB engine


The RB engine is an oversquare 2.0-3.0 L straight-6 four-stroke gasoline engine from Nissan produced from 1985 to 2004. The RB followed the 1983 VG-series V6 engines to offer a full, modern range in both straight or V layouts. It was part of a new engine family name PLASMA.
The RB engine family includes single overhead camshaft and double overhead camshaft engines. Both SOHC and DOHC versions have an aluminium head. The SOHC versions have 2 valves per cylinder and the DOHC versions have 4 valves per cylinder; each cam lobe moves only one valve. All RB engines have belt driven cams and a cast iron block. Most turbo models have an intercooled turbo, and most have a recirculating factory blow off valve to reduce compressor surge when the throttle quickly closes.
The RB engines are derived from the six-cylinder L20A engine, which has the same bore and stroke as the RB20. All RB engines were made in Yokohama, Japan where the VR38DETT engine was also made. Some RB engines were rebuilt by Nissan's Nismo division at the Omori Factory in Tokyo as well. All Z-Tune Skylines were rebuilt at the Omori Factory.
Since 2019, small-scale production of the RB26 blocks and heads are currently being produced as part of Nismo's Heritage Series.

Bore and stroke

All Nissan engines follow a naming convention, identifying the engine family, displacement, features present—see the list of Nissan engines for details.
The stock dimensions for the Nissan RB Engine:
  • RB20 -, bore x stroke:
  • RB24 -, bore x stroke:
  • RB25 -, bore x stroke:
  • RB26 -, bore x stroke:
  • RB30 -, bore x stroke:
  • "D" indicates a dual overhead cam as opposed to a single overhead cam
  • "E" indicates the individual engine ports are electronically fuel-injected 'single-cam'
  • "S" indicates the engine is carbureted
  • "T" indicates the engine has a factory installed turbocharger
  • "TT" indicates the engine has factory installed twin turbochargers
  • "P" indicates the engine runs on LPG

    RB20 (2.0L I6)

The first RB20ET/DE/DET engines were fitted to the HR31 Skyline and the Nissan Fairlady 200ZR, produced from August 1985. The early twin cam engines featured the NICS injection system, while the later twin cam engines used ECCS. Later versions which used ECCS engine management, discarded the twelve tiny runners for six much larger ones. It was also fitted to the A31 Cefiro, C32 and C33 Laurel. The Fairlady 200ZR was fitted with an intercooled NICS type RB20DET.
The first RB20E engine was used in the C32 Nissan Laurel, produced from October 1984.
Laurels, R32 Skyline and Cefiros used the second series RB20E/DE/DET. This had an improved head design, and used the ECCS injection system. These later motors are known as "Silver Top" engines.
The RB20DET-R was used in the Nissan Skyline 2000GTS-R and was limited to 800 units.
There were a variety of 2.0 L RB20 engines produced:
  • RB20E
  • :single-cam
  • :Power: at 5600 rpm
  • :Torque: at 4000–4400 rpm
  • :Camshaft duration: 232° intake; 240° exhaust
  • :Camshaft lift: 7.3 mm intake, 7.8 mm exhaust
  • RB20ET
  • :single-cam, turbocharged
  • :Power: at 6000 rpm
  • :Torque: at 3200 rpm
  • RB20DE
  • :twin-cam
  • :Power: at 6400 rpm
  • :Torque: at 5600 rpm
  • :Camshaft duration: 232° intake, 240° exhaust
  • :Camshaft lift: intake, exhaust
  • RB20DET
  • :twin-cam, turbocharged
  • :Power: at 6400 rpm
  • :Torque: at 3200 rpm
  • :Camshaft duration: 240° intake, 240° exhaust; 248° intake, 240° exhaust
  • :Camshaft lift: intake, exhaust; intake, exhaust
  • RB20P
  • :single-cam, 12 valves, autogas LPG
  • :Power: at 5600 rpm
  • :Torque: at 2400 rpm
  • RB20DET-R
  • :twin-cam, turbocharged
  • :Power: at 6400 rpm
  • :Torque: at 4800 rpm
  • RB20DE NEO
  • :twin-cam
  • :Power:
  • :Torque:

    RB24S (2.4L I6)

This is a comparatively rare engine, as it was not produced for the Japanese domestic market. These were fitted to some left hand drive Nissan Cefiros exported from Japan new. Mechanically, the RB24S combines an RB30E head, RB25DE/DET block and RB20DE/DET crank with 34 mm height pistons. The resulting bore and stroke combined to form a inline-six engine.
This engine used carburetors instead of the Nissan ECCS fuel injection system. It is able to rev higher than the RB25DE/DET as well as being almost the same displacement as the RB25DE/DET. A common modification is to fit a twin cam head from other RB series motors while retaining the carburetor set-up. The standard single cam form produced at 5,000 rpm and of torque at 3,000 rpm.

RB25 (2.5L I6)

The RB25 series of engines was first introduced in the R32 Nissan Skyline GTS25 sedan and coupe models in 1991. The RB25DE and DET variants produced from August 1993 also featured NVCS for the intake cam. This gave the new RB25DE more power and torque at lower rpm than the previous model. From 1995, both the RB25DE and RB25DET had a revised electrical system and the turbocharger on the RB25DET had a ceramic turbine wheel rather than aluminium. The most obvious change to the system was the introduction of ignition coils with built in ignitors, therefore the coil ignitor that was on previous models was not used. Other changes were a different air flow meter, ECU, cam angle sensor and throttle position sensor. Mechanically the series 1 and 2 are very similar, the only mechanical difference would be the camshafts as the series 2 cam angle sensor's shaft that goes into the exhaust cam is slightly different. Early series 2 featured the traditional Mitsubishi CAS which was later swapped for the Black Hitachi CAS which used a grooved shaft because of a half circle positioning tooth which occasionally broke off when removing CAS.
In May 1998 a NEO head was fitted, which enabled the engine to be classified as a low emission vehicle engine due to their lower fuel consumption and emission output. The NEO head featured solid lifters rather than hydraulic, revised camshafts, with on/off solenoid variable VCT, used a hotter thermostat, model-specific coil packs and a revised inlet manifold in particular the RB25DE NEO which had two inlets going into the inlet manifold. The combustion chamber of the head is smaller so model-specific pistons are used to compensate. The turbo received the larger OP6 turbine wheel, while some came with an aluminium compressor and super alloy turbine wheels, others had the nylon plastic compressor wheel and ceramic turbine wheel. Turbo engines were upgraded to use GT-R spec connecting rods. Some also used an N1 type oil pump and had the oil pump drive collar on the crank revised to help cope with the breakage problems associated with fast, high revs.
All in all they are quite a different engine in their own right — a culmination of 20 years of Nissan RB engine building rolled into one.
The non-VCT, non-turbo RB25DE was fitted to the R32 Skyline, the VCT turbo and non-turbo was fitted to R33 Skylines and the WNC34 Stagea and the Laurel C34. R34 Skyline, C35 Laurel and later Stagea models use the NEO RB.
The 2.5 L RB25 engine was produced in four different forms:
  • RB25DE
  • :twin-cam, non-turbo with 10:1 compression ratio
  • :Power: at 6000 rpm
  • :Torque: at 4000 rpm
  • RB25DET
  • :twin-cam, turbocharged with 9:1 compression ratio
  • :Power:
  • :Torque:
  • RB25DE NEO
  • :twin-cam, non-turbo with 10:1 compression ratio
  • :Power: at 6000 rpm
  • :Torque: at 4000 rpm
  • RB25DET NEO
  • :twin-cam, turbocharged with 9:1 compression ratio
  • :Power: at 6400 rpm
  • :Torque: at 3200 rpm)

    RB26 (2.6L I6)

RB26DE

The RB26DE is a naturally aspirated variant of the RB26DETT made specifically for the 1992 Nissan Skyline Autech Version GTS-4 sedan. Mechanically, it is similar to the RB26DETT as it uses the same cylinder head, bore and stroke and individual intakes as the RB26DETT, minus the usage of a parallel twin-turbo system. The engine and ECU were tuned by Autech and S&S Engineering to make at 6,800rpm and at 5,200rpm. It also has a higher compression ratio than the RB26DETT, at 10.5:1.

RB26DETT

The RB26DETT engine is a twin-turbo inline-six engine manufactured by Nissan, for use in the 1989-2002 Nissan Skyline GT-R. The RB26DETT engine block is made from cast iron, while the cylinder head is made from aluminium alloy, which contains DOHC 4 valves per cylinder setup. The intake of the RB26DETT varies from other RB-series motors in that it has six individual instead of a single throttle body. The engine also uses a parallel twin-turbo system, using a pair of T25-type ceramic turbochargers set by the wastegates to limit boost pressure to, although the Skyline GT-R has a built in boost restrictor to keep boost under.
The first 2.6 L RB26DETT was rated by Nissan at around at 6,800 rpm and at 4,400 rpm. By the end of production, power levels had gone up to around at 6,800 rpm and at 4,400 rpm, not only because of developments and modifications to the engine, but also because of the "Gentlemen's Agreement" made between automakers at the time to limit the "advertised" horsepower of any vehicle to. While the published figures from Nissan were as quoted above, it has been known among enthusiasts that the car actually had a factory power output closer to the figure. The RB26 is widely known and became quite popular for its strength and power potential thanks to its iron block and forged internals, making it a modification friendly platform for tuners and aftermarket modifications in general.
Some factory features of the RB26DETT:
  • 6 throttle body intake
  • Solid lifter valve actuation, shim under bucket
  • Belt driven cams
  • CAS driven off exhaust cam, tells ECU crank/cam position
  • water cooled, oil pressure lubed turbos
  • OEM cast pistons have cooling channels under the crowns
  • Piston oil squirters
  • Sodium filled exhaust valves
  • 8 Counter weighted crankshaft
  • 'I' beam connecting rods
There is a common oiling problem with the pre-1992 R32 RB26 motors, as the surface where the crankshaft meets the oil pump was machined too small, eventually leading to oil pump failure at high rpm. This issue was resolved in later versions of the RB26 with a wider oil pump drive, which is found in all R33+ RB26 motors. Aftermarket performance parts makers also make oil pump extension drive collars to rectify this problem. More recently a spline drive solution has been developed by an aftermarket tuner Supertec Racing who moves away from the OEM flat drive system and uses splines to drive the oil pump gears in the same way as the Toyota's 1JZ-GTE engine found in the Toyota Supra. This kit is available for most uprated RB26 oil pumps including Nissan's own OEM, N1 and Nismo parts, although most high HP RB-series engines all over the world have been proven to be reliable without spline driven oil pumps when built and tuned correctly.
Besides minor cosmetic updates and ECU fine tunings, changes were made in the R34 generation to ball bearing T28 turbochargers as opposed to journal bearing turbos. The R34 GT-R turbos retained the ceramic exhaust turbine wheel. Models that had steel exhaust turbine wheels included the R32 Nismo, R32-R33-R34 N1 models and R34 Nür spec skyline GT-R's.
R34 GT-R model RB26DETT engine specific differences to the R32-R33 engines include:
  • Candy red cam/coil pack covers
  • Different coil cover emblem
  • Plastic CAM gear cover
  • Non-painted inlet plenum
  • Hitachi CAS has different drive fitting compared to earlier R32-R33 exhaust cams
  • Igniter built into coil packs
  • Ball bearing turbochargers with ceramic exhaust turbine wheels
  • Stainless steel dump pipes
  • Sump front differential has a different ratio
  • Different diameter coolant/heater pipes on intake side of block
  • Dual mass flywheel
Originally, the R32 GT-R was planned to have the 2.4 L RB24DETT and compete in the 4000 cc class. This was at a time when Nismo was going through the process of designing the R32 GT-R to be a Group A race car. However, when the engineers added the AWD system, they found that it made the car heavier than expected and as a result, much less competitive. Nismo made the decision to make the engine a 2.6 L twin-turbo and compete in the higher 4500 cc class, resulting in the RB26DETT engine many known today.
file:Nissan Skyline GT-R R34 V Spec II.jpg|thumb|The Nissan Skyline GT-R V-spec II is powered by the RB26DETT.
The RB26DETT was used in the following vehicles:
  • Nissan Skyline GT-R BNR32
  • Nissan Skyline GT-R BCNR33
  • Nissan Skyline GT-R Autech Version 40th Anniversary BCNR33
  • Nissan Skyline GT-R BNR34
  • Nissan Stagea 260RS WGNC34改
  • Tommykaira ZZII