VG30DETT Engine

VG30DETT is a 3.0-liter V6 motor. Being for sale in the United States between 1990 and 1996, it was applied for Nissan 300ZX Twin Turbo for the American market and Nissan Fairlady Z in Japan (till 2000).

Though 300ZX automobile could be also equipped with VG30DE motor, VG30DETT became the most widespread choice thanks to twin turbochargers.

Engine Manufacture

Its name can tell a lot about this motor as Nissan opts for engine’s name utilizing expository code of letters and numbers. For instance, VG is a name of the motors line.

Manufacture of VG motors was launched in 1983 and lasted till 2004.  They were preceded by motors of L range, released between 1967 and 1983. The debut VG30DETT motor was produced in the United States in 1990. It was manufactured for 6 years, till 1996, though in 1994, Nissan VQ motor, which is still manufactured, substituted it.

Furthermore, while VG signifies the motor series, the other symbols are also important.

Thus, number 30 indicates the engine’s 3.0-liter capacity; D implies that valve mechanism features dual overhead camshafts; E stands for the electronic fuel injection while TT denotes the motor’s twin turbochargers. Besides, there are also VG30DET motors, where one T means that engine is supplied with only one turbocharger.

VG30DETT gained great popularity due to its outstanding output. It was able to reach 300 hp and a torque of 283 lb/ft.

In 1990, Z-automobiles by Nissan brand turned into the best selling sports vehicles available for sale. More than 1 million cars were purchased that year.

Besides, at the 1990 Super Bowl, Nissan even presented an ad, in which 300ZX won the drag race, competing with motorcycle, airplane and LeMans race automobile. However, that commercial was never showed again.

VG30DETT Specs

The breakdown of the engine code is as follows:

  • VG – Engine Family
  • 30 – 3.0 Liter Displacement
  • D – DOHC (Dual Overhead Camshafts)
  • E – Multi Point Fuel Injection
  • E – Twin-Turbocharged
Engine code VG30DETT
Layout Four stroke, V6
Fuel type Gasoline (petrol)
Production 1987-2000
Displacement 3.0L, 2,960 cc (180.62 cu in)
Fuel system Multi Point Fuel Injection
Power adder Twin T22/TB02 turbochargers
Power output 280 PS (206 KW; 276 HP) at 6,400 rpm
284 PS (209 KW; 280 HP) at 6,400 rpm
330 PS (242 KW; 325 HP) at 6,800 rpm
Torque output 382 Nm (39.0 kg·m; 281.9 ft·lb) at 3,200 rpm
384 Nm (39.2 kg·m; 283.4 ft·lb) at 3,200 rpm
388 Nm (39.6 kg·m; 286.3 ft·lb) at 3,600 rpm
Firing order 1-2-3-4-5-6
Dimensions (L x W x H):
Cylinder block alloy Cast-iron
Compression ratio: 8.5:1
Cylinder bore: 87.0 mm (3.43 in)
Piston stroke: 83.0 mm (3.27 in)
Number of piston rings (compression / oil): 2 / 1
Number of main bearings: 4
Cylinder inner diameter (standard): 87.000-87.010 mm (3.4252-3.4256 in)
Piston skirt diameter (standard): 86.975-86.985 mm (3.4242-3.4246 in)
Piston pin outer diameter: 21.993-22.001 mm (0.8657-0.8662 in)
Piston ring side clearance: Top 0.040-0.073 mm (0.0016-0.0029 in)
Second 0.030-0.063 mm (0.0012-0.0025 in)
Oil 0.015-0.185 mm (0.0006-0.0073 in)
Piston ring end gap: Top 0.21-0.40 mm (0.0083-0.0157 in)
Second 0.50-0.76 mm (0.0197-0.0299 in)
Oil 0.20-0.76 mm (0.0079-0.0299 in)
Connecting rod small end diameter: 22.000-22.012 mm (0.8661-0.8666 in)
Connecting rod center distance: 154.1-154.2 mm (6.067-6.071 in)
Crankshaft main journal diameter: 62.975 mm (2.4763 in)
Crankpin diameter: 49.974 mm (1.9675 in)
Crankshaft center distance: 41.47-41.53 mm (1.6327-1.6350 in)
Cylinder head
Block head alloy Aluminium
Valve Arrangement: DOHC, belt drive
Head surface flatness Less than 0.05 mm (0.002 in)
Valves: 24 (4 valves per cylinder)
Intake valve timing 248°
Exhaust valve timing: 248°
Valve head diameter: INTAKE 34.0-34.2 mm (1.339-1.346 in)
EXHAUST 29.5-29.7 mm (1.161-1.169 in)
Valve length: INTAKE 103.1-103.3 mm (4.06-4.067 in)
EXHAUST 103.6-103.8 mm (4.079-4087 in)
Valve stem diameter: INTAKE 6.965-6.980 mm (0.2743-0.2748 in)
EXHAUST 7.945-7.960 mm (0.3128-0.3134 in)
Valve spring free length: OUTER 43.1 mm (1.697 in)
INNER 43.1 mm (1.697 in)
Camshaft cam height: INTAKE 40.405-40.595 mm (1.5907-1.5982 in)
EXHAUST 40.405-40.595 mm (1.5907-1.5982 in)

Applications

  • 1987 Nissan MID4-II Concept (non-production)
  • 1989–2000 Nissan Fairlady Z Twin Turbo (Japan)
  • 1990–1996 Nissan 300ZX Twin Turbo (US)

 

Peculiarities of VG30DETT Efficiency

Being built on the framework of non-turbo VG30DE, this motor was subjected to various modifications with the purpose of getting great performance results.

Having bore and stroke of 87×83 mm, it kept compression index of 8.5.

Power of 300 hp and a torque of 283 lb/ft was achieved thanks to upgrading of twin Garrett T22/TB02 turbochargers and dual intercoolers. The capacity was 3.0 liters (2,960cc or 180 cu in).

To see how fantastic that engine was for 1990, you are free to compare it with the one of 1990 Ford Mustang, which was a 5.0-liter motor with the output of 225 hp and a torque of 300 ft/lb.

Having less capacity but producing more power, 300ZX was a real success. And it was the main merit of twin turbochargers.

Despite having many more astonishing peculiarities, VG30DETT became the final Nissan motor, comprising 4 valves per cylinder, double overhead camshafts plus a turbocharger. Additionally, RB20DET motor had the identical configuration.

Head and Block Construction

VG30DETT featured an iron block with aluminum heads, which made the motor rather robust to cope with the increased power, produced by twin turbochargers. Moreover, owners of these engines state that they can be very durable if proper maintenance is provided.

The valve mechanism contained double overhead camshafts, variable valve timing plus Nissan’s Valve Timing Control System. Variable valve timing deals with improving performance and raising fuel efficiency.

As VG30DETT is a 6V motor with double overhead camshafts, de facto, it features four camshafts (a quad-cam). In total, there are 24 valves with 4 valves per cylinder.

 

VG30DETT Engine Problems and Reliability

VG30DETT is often referred as a bulletproof engine. Usually, troubles arise because of the old thing crashing and corroded connectors. Additionally, first versions of motors had troubles with fuel injectors. But oil leakage or heating problems aren’t common.

In the vehicles, released in 1990-1991, brake master cylinder may start leaking after 40,000-50,000 miles run. The replacement will cost you about $200. The latest parts are upgraded and so, they have a longer lifespan. If a car you are going to buy has any of these malfunctions, tell the distributor that you will pay less and spend the saved sum on the details’ renovation.

Automobiles with turbocharging, released before 1/90, plus naturally aspirated vehicles, manufactured before 7/90, may face troubles with defective valves. Valves can unscrew themselves from the head, leading to the rough idle and compression reduction. In order to prevent this problem, it’s advisable to inspect the motor number. Turbo vehicles with motor numbers below 619550 and naturally aspirated vehicles with numbers below 777599 often face this malfunction. Additionally, take a look at the data tags attached to the doorpost at the driver’s side and under the hood. They contain information about date of manufacture along with serial numbers.

Compression pressure
Standard 12.0 kg/m2 (171 psi) / 300 rpm
Minimun 9.0 kg/m2 (128 psi) / 300 rpm
Compression differential limit between cylinders 1.0 kg/m2 (15 psi) / 300 rpm
Oil system
Oil consumption , L/1000 km (qt. per miles) up to 0.5 (1 qt. per 1200 miles)
Recommended engine oil 5W-30, 10W-30, 10W-40, 20W-40, 20W-50
Oil type API API SG
Engine oil capacity (Refill capacity) With filter change 3.4 l (3-5/8 Us. qt., 3 Imp. qt)
Without filter change 3.0 l (3-1/8 Us. qt., 2-5/8 Imp. qt.)
Oil change interval, km (miles) Every 6,000 (3,750)
Oil pressure Idle speed (78 kPA, 0.8 kg/cm3, 11 psi)
3,000 rpm (353-451 kPA, 3.6-4.6 kg/cm3, 51-65 psi)
Ignition system
Spark plug NGK Platinum-tipped type: PFR5B-11B
Spark plug tightening torque 20-29 Nm; 2.0-3.0 kg·m; 14-22 ft·lb

 

To Sum It Up

Remaining rather a widespread motor, VG30DETT is a strong and enduring engine, able to achieve 300 hp with almost no troubles.

Having less capacity and greater output than its rival, 5.0-liter 1990 Ford Mustang, 300ZX automobile became one of the most popular sports cars of that time. However, the motor was in stock only at the American market and was sold only till 1996. So, there is a pretty limited amount of these engines, which still function. Usually, they are kept by collectors or drivers, obsessed with high performance cars. So, it can be pretty hard to acquire VG30DETT.


Written by Dan Hoffman

Dan Hoffman

Dan is a co-founder of Engineswork. He knows everything about internal combustion engines. Ask your questions in comments down below this article – he will be glad to help you anytime.

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