3-44. CYLINDER BLOCK - MAINTENANCE INSTRUCTIONS.
a. The cylinder block serves as the main structural part of the engine. Transverse webs provide rigidity
and strength and ensure alignment of the block bores and bearings under load.
b. The block is bored to receive replaceable cylinder liners. The cylinder block is designed to provide
water cooling below the air inlet port belt. An air box between the cylinder banks and extending around the
cylinders at the air inlet port belt conducts the air from the blower to the cylinders. Air box openings on each
side of the block permit inspection of the pistons and compression rings through the air inlet ports in the
cylinder liners. The air box openings in the cylinder block assembly are about 1 7/8" x 3 1/8" (4.76 x 7.94 cm)
and are covered with cast covers. The camshaft bores are located on the inner side of each cylinder bank near
the top of the block.
c. The upper halves of the main bearing supports are cast intergral 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.
d. The top surface of each cylinder bank is grooved to accommodate a block-to-head oil seal ring. Each
water or oil hole is counterbored to provide for individual seal rings.
e. Each cylinder liner is retained in the block by a flange at its upper end. The liner flange rests on an
insert located in the counter- bore in the block bore. An individual compression gasket is used at each cylinder.
When the cylinder heads are installed, the gaskets and seal rings compress to form a tight metal-to-metal
contact between the heads and the block.
f. Cylinder block assemblies include the main bearing caps and bolts, dowels and the necessary plugs.
Since the cylinder block is the main structural part of the engine, the various sub-assemblies must be removed
from the cylinder block when an engine is overhauled.