The 1984-1989 Z31 came with five different engine packages. In the North America market the Z31 only came with the VG30E and VG30ET motors.

In the Domestic market (Japan), the Z31 was offered with the following motors, VG30DE, VG30ET, VG20ET, and RB20DET.

The Euro market also only was offered the VG30E and VG30ET motors, But they did offere a higher lift cam known in the US market as the Nismo cam.

VG30 Series Specifications

USDM United States Domestic Market

Specs for the USDM VG30E are as Follows:

Displacement	2960 cc (181 cu. in)
Bore and Stroke	87.0 X 83.0	Can be boared to 90mm safely. Break through occurs at 3.78" per defrag010 of Z31performance.com
Compression Ratio	9.0:1
Horsepower	160hp at 5200 rpm	165hp at 5200 rpm on late w-series models 1988-1989
Torque	24.0 kg-m (173ft-lbs) torque at 4000 rpm

Specs for the Early 1984 to 5/1987 VG30ET USDM are as Follows:

On the 1984-1987 turbo cars came with a Nissan made Garrett based T3 Turbocharger.

The engine was either a type A or type B sub-designation from 1984 to April 1987. These have Press fit wrist pins.

Specs for the Late 5-87 to 1989 VG30ET USDM are as Follows:

On the 1988 and later turbo cars came with a Nissan made Garrett based T25 Turbocharger.

The W-series engines featured redesigned water jackets for additional cooling, fully floating piston wrist pins, and more power

Displacement	2960 cc (181 cu. in)
Bore and Stroke	87.0 X 83.0
Compression Ratio	8.3:1
Horsepower	205 hp at 5200 rpm
Torque	1.4 kg-m (227ft-lbs) at 3600 rpm torque

JDM Japanese Domestic Market

VG30ET Specification are as follows:

The VG30ET was the same as the USDM motors but made about 5 less horsepower due to emmission standards.

Displacement	2960 cc (181 cu. in)
Bore and Stroke	87.0 X 83.0
Compression Ratio	7.8:1
Horsepower	195 Hp at 5200RPM
Torque	31.5Kgm (227ft-lbs) at 3600 RPM

European Market

VG30ET Specification are as follows:

The European models made 230 hp (170 kW) in turbo form due to a better camshaft profile, also known outside of Europe as the Nismo camshafts. Some models were also equipped without catalytic converters.

VG20 Series Specifications

The VG20ET offered in the japanese 200Z, 200ZG, and 200ZS, was basically a VG30ET with the bore and stroke Decreased . The turbo included with the VG20ET had two different settings. At low speeds, the turbo's flap (wastegate?) would stay closed improving the response at low RPMS. At high speeds, the flap would stay open, decreasing resistance and increasing exhaust flow. At its maximum flow, the flap would open at an angle of 27-degrees, while the A/R ranged from 0.21 ~ 0.77.

Though the intake and exhaust manifolds look simular to the VG30ET units, they do not interchange due to the smaller deck height of the VG20.

VG30ET Specification are as follows:

Displacement	1998cc (122 Cu. in)
Bore and Stroke	78.0 X 69.7
Compression Ratio	8.0:1
Horsepower	170 Hp at 6000 RPM
Torque	22.0 kg-m (159 Ft-Lbs) at 4000RPM

VG30DE Series Specifications

The VG30DE was an early version of the motor used in the Later 90+ 300zx. It featured a slightly different block, Dual Overhead Cam Heads, and 24 valve with Nissan's own version of variable valve timing (NVCV) for increased high RPM efficiency. The production blocks and production head castings were used successfully in the Nissan GTP ZX-Turbo and NPT-90 race cars which won the IMSA GT Championship three years in a row.

The easiest way to spot a VG30DE block is there are only 8 head bolts vs the VG30E(T) having 13

VG30DE Specification are as follows:

Displacement	2960 cc (181 cu. in)
Bore and Stroke	87.0 X 83.0
Compression Ratio	10.0:1
Horsepower	190 Hp at 6000RPM
Torque	25.0Kgm (181 Ft. Lbs)at 4400 RPM

RB20DET Series Specifications

The 200ZR had the Last straight six offered in a Z it was the RB20DET. These early twin-cam RBs (identified by their red ribbed cam cover) run a relatively low 8.5:1 static compression ratio, 24 valve Dual Overhead Cam Head, and a ceramic wheeled turbocharger with an air-to-air intercooler which is fed by the 200ZR’s Hood scoop. It also used a NICS dual-stage twin-runner Ignition system, a hot-wire airflow meter and direct-fire ignition are also used.

The RB20DET has an cast iron block and aluminium head. All RB engines have belt-driven camshafts and all cam lobes move only one valve.

RB20DE Specification are as follows:

Displacement	1998cc (122 Cu. in)
Bore and Stroke	78.0 X 69.7
Compression Ratio	8.5:1
Horsepower	180 Hp at 6400RPM
Torque	23.0Kgm (174 Ft. Lbs)at 3600 RPM

RB20DET Camshaft Specification are as follows:

Duration Intake	248°
Duration Exhaust	240°
Lift Intake	7.8mm
Lift Exhaust	7.8mm

Sources used on this page:

• 1984-1988 Nissan 300ZX Factory Service Manual
• VG30DE Image is from RichZilla, http://www.z31club.com
• RB20DET information from 1986 JDM Dealer Brochure
• VG20ET information from 1984 JDM Dealer Brochure