Description

In the late 1987 model year, Nissan changed the design of the VG30 engine, slightly, to provide a decrease in noise levels and an increase in power output. There is a lot of confusion as to what changes were actually made. This is a comprehensive listing of changes that were made to the VG30 engine.

Changes to the VG30 Engine (to create the W-series engine):
1987 Nissan-Datsun 300ZX V6-2960cc 3.0L SOHC MFI (VG30E)
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VG30 Engine Modifications

Models All Models with VG30
Section Engine Mechanical
Classification EM87-010
Bulletin No. TS87-191
Date December 28, 1987
Applied Models All vehicles with VG30 Engine

VG30 ENGINE MODIFICATIONS:
Beginning with April, 1987 production, several major components of the VG30 engine have been changed to decrease noise levels and improve power output.

The MODIFIED AND NON-MODIFIED engines can be identified by the engine serial number as follows:

MODIFIED NON-MODIFIED
(XXXXXX W) (XXXXXX A)
OR
(XXXXXX B)

The major engine components that have been changed to create the “W” engine are shown below. In addition, a summary of changes is provided for each component.

Cylinder Block

Description

Six new water galleries were added at the exhaust side of the cylinders. In addition, the oil pan bolt holes have been altered in the modified cylinder block. The holes have been chamfered to allow usage of a liquid oil pan gasket.

Identification

The “W” engine bare block will NOT be stamped with a “W”. Check for additional water galleries to identify a modified bare block. These chamfered bolt holes are also helpful in identifying the modified bare block.

Piston and Piston Pins

Description

The piston and pin have been changed to a full-floating type, with two snap rings to locate the piston pin. Also, piston pin outer diameter has been decreased.

Identification

The modified piston can be identified by a “W” mark on the piston skirt. NOTE: A “W” piston requires a modified connecting rod, wrist pin, and piston rings.

Connecting Rod

Description

The modified connecting rod has been increased in weight, along with an increase in small end internal bore.

Identification

It can be identified by a “W” stamped in the side of the rod shaft as shown in illustration. NOTE: A “W” connecting rod requires a “W” piston, new style wrist pin, and modified crankshaft.

Crankshaft, Pulley, Bolt, and Washer

Description

The crankshaft front tip was lengthened by 18.7 mm (0.736) in. The crankshaft pulley width was increased by 13.6 mm (0.535 in.). There are now two keys instead of just one.

Identification

Additional Info

Nissan made a spacer to allow you to fit the older A/B series crank pulleys to the W series cranks. The part number is 12308-V5321. i164.photobucket.com_albums_u11_az_zbum_z31_20parts_12308-v53211.jpg

Cylinder Head

Description

Three new water galleries were added to each cylinder head (at the exhaust side). These match the new galleries in the block.

Identification

Cylinder Head Gasket

Description

Three new holes were added to the gasket on the exhaust side, and the six holes in the intake side of the gasket were decreased in size.

Identification

The tab shape can be used to identify the modified gasket from the non-modified gasket.

A/B and W Series Component Compatibility Chart

Engine
Type
Cylinder
Head
Head
Gasket
Cylinder
Block
Short
Engine
Acceptable
Combination
A/B Modified Former Former Yes
A/B Former Former Modified Yes
A/B Former Former Former Yes
A/B Modified Modified Modified Yes
A/B Modified Former Modified Yes
A/B Modified Modified Former No
A/B Former Modified Modified No
A/B Former Modified Former No
A/B Former Former Modified Yes
A/B Modified Modified Modified Yes
A/B Modified Former Modified Yes
A/B Former Modified Modified No
Engine
Type
Cylinder
Head
Head
Gasket
Cylinder
Block
Short
Engine
Acceptable
Combination
W Modified Modified Modified Yes
W Modified Modified Modified Yes
W Any combination of former components No
 
resources/w-series.txt · Last modified: 2014/09/08 18:05 (external edit)
 
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