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(2) Inspect connecting rods and connecting rod caps
for cylinder i d e n t i f i c a t i o n . Identify t h e m , i f neces-
sary.
(3) Remove connecting r o d cap. I n s t a l l connecting
rod bolt guide set on connecting rod bolts. Push each
piston a n d r o d assembly o u t o f cylinder bore. B e
c a r e f u l n o t t o n i c k c r a n k s h a f t j o u r n a l s .
(4) A f t e r r e m o v a l , i n s t a l l bearing cap o n t h e m a t -
i n g rod.
CLEANING
AND
INSPECTION
(1) Clean c y l i n d e r block thoroughly and check a l l
core hole plugs for evidence of leaking.
(2) I f n e w core plugs a r e installed, see "Engine
Core O i l a n d C a m Plugs".
(3) E x a m i n e block for cracks or fractures.
CYLINDER
BORE
INSPECTION
The cylinder w a l l s should be checked f o r o u t of-
r o u n d a n d taper w i t h Tool C-119. I f t h e cylinder
bores show more t h a n 0.127 m m (0.005 inch) out-of-
r o u n d , or a taper of more t h a n 0.254 m m (0.010
inch), or i f t h e cylinder walls are badly scuffed or
scored, the c y l i n d e r block should be bored and honed,
and new pistons a n d r i n g s fitted. Whatever type o f
b o r i n g equipment i s used, boring and h o n i n g opera-
t i o n should be closely coordinated w i t h the fitting o f
pistons and r i n g s i n order t h a t specified
clearances
may be m a i n t a i n e d .
ENGINE CORE OIL AND CAM PLUGS
REMOVAL
U s i n g a b l u n t tool such as a d r i f t or a screwdriver
and a hammer, s t r i k e t h e bottom edge o f the cup
p l u g . W i t h t h e cup p l u g rotated, grasp
firmly
w i t h
pliers or other suitable too l a n d remove p l u g (Fig. 1).
CAUTION: Do not drive cup plug into the casting as
restricted cooling can result and cause serious en-
gine problems.
CYLINDER
BLOCK
fc§£^
y
/
/
—
/
/ -
SECOND
REMOVE PLUG
WITH PLIERS
FIRST
STRIKE HERE
WITH HAMMER
DRIFT
INSTALLATION
Thoroughly clean inside of cup p l u g hole i n c y l i n -
der block or head. Be sure t o remove o l d sealer.
L i g h t l y coat inside o f cup p l u g hole w i t h Loctite S t u d
N ' B e a r i n g M o u n t , or equivalent. M a k e c e r t a i n t h e
new p l u g is cleaned o f a l l o i l or grease. U s i n g proper
drive p l u g , drive p l u g into hole so t h a t t h e sharp
edge o f t h e p l u g is a t least 0.5 m m (0.02 inch) inside
t h e lead-in chamfer.
I t i s not necessary to w a i t for c u r i n g of the sealant.
The cooling system can be filled a n d t h e vehicle
placed i n service immediately.
PISTONS, PINS AND RINGS
The pistons are cam ground so t h a t the diameter a t
the p i n boss is less t h a n i t s diameter across t h e
t h r u s t face. This allows for expansion under n o r m a l
operating conditions. Under operating temperatures,
expansion forces t h e p i n bosses away
f r o m
each
other, thus, causing t h e piston t o assume a more
nearly r o u n d shape. I t is i m p o r t a n t t h a t pistons be
checked for taper and e l l i p t i c a l shape before they are
fitted i n t o the cylinder bore (Fig. 2).
3.886-3.891
RN297
Fig. 1 Core Hole Plug Removal
THE DIAMETER (D)
ELLIPTICAL SHAPE OF THE PISTON
SHOULD BE .000 TO .0006
SKIRT SHOULD BE .010 (.254mm) TO
(.0152mm) IN.
.012 (.304mm) IN. LESS AT DIAMETER
LARGER THAN (C)
(A) THAN ACROSS THE THRUST
FACES AT DIAMETER (B)
8909-57
Fig. 2 Piston Measurements
FINISHED
PISTONS
A l l pistons are machined t o t h e same w e i g h t i n
grams, regardless of oversize, to m a i n t a i n piston bal-
ance. F o r cylinder bores w h i c h have been honed or
bored new pistons are furnished w i t h
fitted
pins,
available i n standard and oversize—0.508 m m (0.020
inch).
FITTING
PISTONS
Piston and cylinder w a l l must be clean and dry.
Specified clearance between the piston and the c y l i n -
der w a l l is 0.0127 to 0.0381 m m (0.0005 t o 0.0015
inch).
Piston diameter should be measured a t the top o f
s k i r t 90° to piston p i n axis. Cylinder bores should be
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