The cylinder block (Figs. 1 and 2) serves as the main
Each cylinder liner is retained in the block by a flange at
structural part of the engine. Transverse members, cast
its upper end. The liner flange rests on a cast iron insert
integrally, provide rigidity and strength and ensure
located in the counterbore in the block bore. An
alignment of the block bores and bearings under load.
individual compression gasket is used at each cylinder.
Cylinder blocks for the three, four and six-cylinder
engines are identical in design and dimensions except
When the cylinder head is installed, the gaskets and
for length. The two ends of the block are similar, so the
seal rings compress sufficiently to form a tight metal-to-
flywheel housing and the gear train can be assembled to
metal contact between the head and block.
New service replacement cylinder block assemblies
The block is bored to receive replaceable cylinder liners.
include the main bearing caps and bolts, dowels and the
Water jackets, which extend the full length of the bores,
are divided into upper and lower sections which are
connected by hollow struts (Fig. 2). Coolant from the
Since the cylinder block is the main structural part of the
pump enters at the bottom of each water jacket and
engine, the various sub-assemblies must be removed
leaves at the top of the block through holes which
from the cylinder block when an engine is overhauled.
register with corresponding openings in the cylinder
The hydraulically operated overhaul stand (Fig. 5)
provides a convenient support when stripping a cylinder
An air box (Fig. 2) surrounding the water jackets
block. The engine is mounted in an upright position. It
conducts the air from the blower to the air inlet ports in
may then be tipped on its side, rotated in either direction
90 ° or 180 ° c where it is locked in place and then, if
the cylinder liners. Air box openings (Fig. 3) on the side
desired, tipped back with either end or the oil pan side
of the block opposite to the blower provide access to the
air box and permit inspection of the pistons and
compression rings through the air inlet ports in the
The camshaft and balance shaft bores are located on
opposite sides near the top of the block.
The upper halves of the main bearing supports are cast
integral with the block. The main bearing bores are line-
bored with the bearing caps in place to ensure
longitudinal alignment. Drilled passages in the block
carry the lubricating oil to all moving parts of the engine,
eliminating the need for external piping.
The perimeter of the top surface of the cylinder block is
grooved, outside of the cam pockets, to accommodate a
block-to-head oil seal ring. The top surface of the block
is also counterbored at each water or oil passage to
Fig. 1 - Typical Cylinder Block