s h a f t , damage. excessive heat or other
block, a d j a c e n t t o i t s p e r m a n e n t
damage.
location in the engine as estab-
lished at the time of manufacture.
The No. 1 main bearing cap is al-
D. If the main bearing bores are not in
ways located at the end opposite
alignment when a replacement bearing
the flywheel end of the cylinder
cap
is
used,
the
block
must
be
block.
As
originally
line-bored. Install the bearing caps
manufactured, the main bearing
in their original positions and tighten
caps a r e i n s t a l l e d w i t h t h e n u m -
the bolts to 165-175 lb-ft (224-238
bered side facing the blower side
Nm) torque. Line bore the block, but
of the engine. Machining of the
do not remove more then 0.001"
cylinder block and main bearing
stock. After boring, all bores must
caps is such that the mating parts
be within the specified limits of 3.812"
are "offset" to prevent installation
to 3.813".
of the bearing caps 180 from their
correct position. However, if an
8. Refer to the Cylinder Block Plugging
engine has been converted for a
Charts at the end of this subsection and
new application and the cylinder
install the necessary plugs and dowels.
and bearing numbering sequence
has been reversed, the bearing
9. Replace loose or damaged dowel pins.
caps must be reinstalled in the or-
The dowels at the ends of the cylinder
iginal positions regardless if the
block must extend 0.625" from the face
block and bearing caps have or
of the block.
have not been renumbered.
The dowels used to retain the crank
shaft thrust washers on the rear main
6. Finished and unfinished main bearing
bearing cap must extend 0.110" to 0.120"
caps are available for replacing bro-
from the surface of the bearing cap.
ken or damaged caps. When fitting a
finished replacement bearing cap, it
NOTE
may be necessary to try several caps
before one will be found to provide
A stepped dowel pin is available to
the correct bore diameter and bore
replace loose pins in the rear main
alignment. If a replacement bearing
bearing cap. Before installing the
cap is installed, be sure to stamp the
stepped pins, rebore the dowel
correct bearing position number on
h o l e s in the bearing cap with a No.
the cap.
11 (0.1910") or No. 12 (0.1890")
drill. After pressing the pins into
NOTE
the bearing cap, remove all burrs
from the base of the dowel pins to
Use the unfinished bearing caps
ensure proper sealing of the
for the front and immediate bear-
thrust washers.
ing positions. The finished bear-
ing
caps,
machined
for
the
crankshaft thrust washers, are to
10. Replace main bearing cap studs, if
be used in the rear bearing posi-
used, which are damaged or broken. In-
tion.
stall new studs to a height of 4"1/32"
above the upper bearing seat at a torque
of 35-75 lb-ft or 47-102 Nm.
C. Main bearing bores are line-bored
with the bearing caps in place and
11. Replace damaged or broken cylinder
thus are in longitudinal alignment.
head studs. Install and drive a new
Bearing bores
may be considered
stud to a height of 4-3/8"1/32" at a min-
properly aligned with one another if
imum torque of 75 lb-ft or 102 Nm.
the crankshaft can be rotated freely
by hand after new bearing shells have
12. Examine the tapped bolt holes for the
been installed and lubricated and the
cylinder head or main bearing cap bolts
bearing caps tightened. If a main
and, if the threads are damaged, "clean
bearing bore is more than 0.001" out
up"
the
threads
or
install
a
helical
thread
insert.
The
tapped
holes
maybe
of alignment, the block must be
line-bored or scrapped. Misalignment
tapped with a 5/8"-11 UNC3B tap. All
may be caused by a broken crank-
cylinder head bolt or stud holes must
Engine (Less Major Assemblies) 11B-11
