Technical data

CONSTRUCTION AND SERVICING OF CYLINDER BLOCK ASSEMBLY
1. Cylinder Block
The cylinder block is a special cast iron casting and is of a full jacket type formed integral with
cylinder liners.
Main bearings are metal-backed copper sintered alloy (kelmet) bearings and are coated with lead
and tin alloy plating on the journal surface and flash-plated over the entire bearing
surface to insure good run-in. Crankshaft thrust is received by the flanged bearing. On
the front bearing area of the camshaft, a metal-backed special copper alloy rolled bushing
is installed. (In engines produced in the initial period of production, this bushing is not
used.) .
2. Crankshaft
The crankshaft is a precision-forging of carbon steel and is supported on bearings to provide
great ridigity. Journals, pins and oil seal areas have been induction-hardened to improve
wear resistance and durability.
3. Flywheel and Ring Gear
The flywheel is produced from iron casting.
The ring gear is produced from a carbon steel and shrinkage-fitted on the flywheel; the gear teeth
are induction-hardened.
4. Piston, Pin and Piston Ring
Aluminum alloy pistons are used for the purpose of reducing engine weight and decreasing
bearing load during high-speed operation. The piston is cam-ground and tapered so it
may become nearly round to obtain the best contact with the cylinder wall during normal
operation.
The piston pin is a hollow, carburized forging, and retains the connecting rod small end to the
piston by a semi-floating system. The piston pin is pressed in the rod. The W33 uses a
snap ring to retain the pin.
Piston rings are made of a special cast iron. Each piston is provided with three compression rings
and one oil ring. The outside surface of the top and oil rings are hard chrome-plated. The
engine uses a semi-keystone type top ring and an oil ring with coil expander.
5. Connecting Rod
The connecting rod is an I-beam section rod with a horizontal split-type big end to provide
greater rigidity.
The connecting rod bearing is a metal-backed special copper alloy bearing and is flash-plated.
6. Front Plate and Gear Case
The front plate is a steel plate and positioned by a dowel pin located in the upper part of the
camshaft gear and a dowel pin in the lower part of the injection pump gear. It is
attached by bolts to the cylinder block. On the left end rear surface, the high-pressure
pump gear housing is installed together with the gear case.