Editing Nissan RB engine (section)

==RB25 (2.5L I6)==
[[File:RB25DET R33.jpg|right|thumb|1993 RB25DET with VCT ([[N-VCT|NVCS]])]]
[[File:NEO RB25DET R34.jpg|right|thumb|1998 NEO RB25DET]]
[[File:R33 RB25DET with Jatco Transmission.jpg|thumb|RB25DET and Transmission pulled from an R33 Skyline GTST]]

The RB25 series of engines was first introduced in the R32 Nissan Skyline GTS25 sedan and coupe models in 1991.<ref>{{cite web|title=Skyline Encyclopedia|url=http://www.southernskylines.com/encyclopedia/r32/GTS-25.html|publisher=Southern Skylines|access-date=2016-12-21|archive-date=2017-04-09|archive-url=https://web.archive.org/web/20170409080306/http://www.southernskylines.com/encyclopedia/r32/GTS-25.html|url-status=live}}</ref><ref>{{Cite web|url=http://gtr-registry.com/en-ecr32-vin-table.php|title = Nissan Skyline ECR32 VIN Table}}</ref> The RB25DE (naturally aspirated) and DET (turbocharged) variants produced from August 1993 also featured [[N-VCT|NVCS]] (Nissan Variable Cam System) for the [[intake manifold|intake]] cam. This gave the new RB25DE more power and torque at lower rpm than the previous model. From 1995 (series 2 engines), both the RB25DE and RB25DET had a revised electrical system and the turbocharger on the RB25DET(S2) had a ceramic turbine wheel rather than aluminium. The most obvious change to the system was the introduction of [[ignition coil]]s with built in ignitors, therefore the coil ignitor that was on previous models was not used. Other changes were a different air flow meter, [[Engine control unit|ECU]], cam angle sensor and throttle position sensor. Mechanically the series 1 and 2 are very similar, the only mechanical difference would be the [[camshaft]]s 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 Motors|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 [[Nissan VVL engine|NEO]] head was fitted, which enabled the engine to be classified as a low emission vehicle ([[Low Emission Vehicle|LEV]]) engine due to their lower [[Fuel consumption in automobiles|fuel consumption]] and emission output. The NEO head featured solid lifters (needing adjustment over time) rather than hydraulic (self adjusting), revised camshafts (higher lift lower duration to complement smaller ports and torque), with on/off [[solenoid]] variable VCT, used a hotter {{convert|82|°C|abbr=on}} thermostat, model-specific coil packs and a revised inlet manifold (the runner diameter is reduced from {{convert|50|to|45|mm|abbr=on}} to increase air velocity and low end torque) 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 rod]]s. 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 [[Nissan Stagea|WNC34 Stagea]] and the [[Nissan Laurel#C34|Laurel C34]]. R34 Skyline, C35 Laurel and later Stagea (WGNC34) models use the [[Nissan VVL engine|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: {{convert|180-200|hp|kW PS|0|abbr=on}} at 6000&nbsp;rpm
*:Torque: {{convert|255|Nm|lbft kgm|abbr=on}} at 4000&nbsp;rpm
*'''RB25DET'''
*:twin-cam, turbocharged (T3 Turbo) with 9:1 compression ratio
*:Power: {{convert|245-250|hp|kW PS|0|abbr=on}} 
*:Torque: {{convert|319|Nm|lbft kgm|abbr=on}}
*'''RB25DE NEO'''
*:twin-cam, non-turbo with 10:1 compression ratio
*:Power: {{convert|197|hp|kW PS|0|abbr=on}} at 6000&nbsp;rpm
*:Torque: {{convert|255|Nm|lbft kgm|abbr=on}} at 4000&nbsp;rpm
*'''RB25DET NEO'''
*:twin-cam, turbocharged (T3 Turbo, "45V3" with OP-6 compressor) with 9:1 compression ratio
*:Power: {{convert|276|hp|kW PS|0|abbr=on}} at 6400&nbsp;rpm
*:Torque: {{convert|362|Nm|lbft kgm|abbr=on}} at 3200&nbsp;rpm)