RB20DET: Our Analysis

The younger, and less sought after brother of the RB26. While it may not be as powerful or competition ready, the RB20 has always had its followers, and it deserves to be looked at.

Nissan RB20DET Engine

What does it mean?

“RB”- denotes engine code. 
“20” –denotes capacity/displacement (1998 cc) 
"D" –denotes twin overhead cams, as opposed to a single overhead camshaft. 
"E" – denotes the fact that individual valve ports are electronically fuel-injected.
"S"-denotes a carburetted engine
"T" – denotes a factory installed turbocharger as standard.
"TT" –denotes twin factory- installed turbochargers as standard. 
"P" –denotes LPG (Liquefied petroleum gas) as required fuel.

Overview.

The first generation RB20ET/DE/DET engines were used in the HR31 Skyline, as well as the Nissan Fairlady 200ZR (Z31 platform), which were produced from August of 1985. Early twin cam engines in the range are generally referred to as 'Red Top' engines, since they sported red cam covers. While the first generation twin cam engines featured the NICS (Nissan Induction Control System) injection system, the later twin cam engines employed the ECCS (Electronic Concentrated Control System). 


In later versions, where the ECCS engine management system was used, the twelve small runners, or cam followers, were replaced with six larger ones, which required the use of a splitter plate in order to retain the twelve valve ports. This modification was first introduced on the A31 Cefiro, and the C33 Laurel. In what was seen at the time as a somewhat retrograde step, an intercooled RB20DET engine running the older and less efficient NICS (Nissan Induction Control System) was fitted to the Fairlady 200ZR, which produced 158 kW(215 hp)@6400, and 264 Nm/ (27.0 kgf/m) @ 3200 rpm.


Although Nissan developed a wide variety of derivatives and variants of the basic 2.0 litre RB 20 engine, none saw any measure of success in motor sport. In fact, it is debateable if any versions were ever considered for competition purposes by engine builders or developers. Nonetheless, below are some of the most widely available variants:

• RB20E – Single cam. Produces 96 to 110 kW (130 to 145 hp) @ 5600 rpm, and 167 to 181 Nm (17 to 18, 5 kgf/m) @ 4400 rpm.
• RB20ET - Single-cam, turbocharged. Produces 125 kW (170 hp)@6000 rpm, and 206 Nm (21.0 kgf/m) @ 3200 rpm.
• RB20DE - Twin-cam. Produces 110 to 114 kW (150 to 155 hp) @ 6400 rpm, and 181 to 186 Nm (18.5 -19 kgf/m) @ 5600 rpm.
• RB20DET - Twin-cam, turbocharged. Produces 158 kW (215hp) @ 6400, and 264 Nm, (27 kgf/m) @ 3200 rpm.
• RB20P - Single-cam. Produces 94 hp @5600 rpm, and 142 Nm @2400 rpm
• RB20DET-R - Twin-cam, turbocharged. Produces 210 hp @ 6400 rpm, and 245 Nm at 4800 rpm. This variant was however produced in a limited production run of only 800 units, and therefore almost impossible to locate.
• RB20DE NEO - Twin-cam. Produces 155 hp, but with significantly improved low-end torque delivery, lower fuel consumption, and measurably lower emissions.
  

Most torque delivery characteristics were accomplished by the simple expedient of altering camshaft duration and valve lift. Some examples are listed below:

RB20DE Cam duration: 232° in, 240° ex. Lift: 7.3mm in. 7.8mm ex.
RB20DET Cam duration: 240°in., 240°ex. Lift: 7.3mm in. 7.8mm ex.
RB20DET Red top Cam duration: 248°in. 240°ex. Lift: 7.8mm in. 7.8mm ex.

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Engine specs.

Type: RB20DET Twin cam, turbocharged, in-line 6 cylinder.
Displacement: 1998 cc
Compression Ratio: 8.5:1
Max. Power: 160 kW/214 bhp @6400 rpm
Max. Torque: 236 Nm/194 ft-lbs @3200 rpm
Bore: 78 mm 
Stroke: 69.7 mm
RPM redline: 7600 rpm
Fuel Injection: Nissan EGI (ECCS)

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Conclusion:

This is a heavy, inline six cylinder, and due to its relatively low power output, is unsuited to competition, which demands small, compact, but above all reliable, and high revving engines. However, due to its legendary smoothness, it is more sought after for installation, or conversion to family sedans and vehicles used for towing trailers, because of it proven reliability in standard form.