Cylinder Block Assembly: Description and Operation

Cylinder Block
The cylinder block is of an enclosed 'Vee' design with 'Nikasil' plated cylinder bores to reduce piston friction, improve warm up and oil retention. A low volume coolant jacket improves warm up time and reduces piston noise levels.

Viewed from the driving position, the right-hand cylinder bank is designated Bank 1 and the left-hand cylinder bank as Bank 2.

The cylinder bores of each bank are numbered 1 to 4, from the front of the vehicle.

Part 1 Of 2:

Part 2 Of 2:

Bedplate
This is a structural casting bolted to the bottom of the cylinder block to retain the crankshaft and to further improve overall rigidity.

Main bearing clearance changes due to expansion are minimized by means of iron inserts cast into the bedplate main bearing supports.

Two hollow dowels align the bedplate with the cylinder block and the joint is sealed by a continuous bead of sealant.

The engine speed sensor is located at the rear of the bedplate and is a variable reluctance sensor that provides an input to the ECM representing engine crankshaft speed and position.

Block Dowels, Block Plugs and Stub Pipe
A shaped plug/cover, known as the 'Valley' plug, is installed to the top of the engine block at the center of the 'Vee' formed by the angle between banks '1' and '2' of the cylinder block.

Ring Dowels
Ring dowels are used as follows:
- To assist in the location and installation of each cylinder head to its respective location on the block.
- Two are used to locate the main sump body to the cylinder block.
- Two are used at the rear of the engine block to locate the mating face of the transmission housing.
- Two are used at the front, one on each side, to locate and align the timing cover and two more each side of the front face to locate the VVT bush carriers (where fitted).
- Two are used each side near the front to locate the accessory mounting bracket and the generator mounting bracket.

Stub Pipe
A stub pipe in the center of the raised part of the block casting for the thermostat housing, accommodates one end of the heater return hose.