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9 - 4
ENGINE
•
S T A N D A R D S E R V I C E
P R O C E D U R E S
INDEX
Page
Engine Performance
4
Form-ln-Place Gaskets
4
Honing Cylinder Bores
5
FORM-IN-PLACE GASKETS
There are numerous places where
form-in-place
gaskets are used on the engine. Care m u s t be t a k e n
w h e n a p p l y i n g form-in-place gaskets. Bead size, con-
t i n u i t y and location are of great importance. Too t h i n
a bead can result i n leakage w h i l e too m u c h can re-
sult i n spill-over. A continuous bead o f t h e proper
w i d t h is essential to obtain a leak-free j o i n t .
ROOM TEMPERATURE
VULCANIZING
(RTV}
R T V silicone form-in-place gasket, n o r m a l l y black
i n color, is available i n three ounce tubes. Moisture
i n t h e a i r causes the RTV m a t e r i a l to cure. T h i s ma-
t e r i a l i s n o r m a l l y used on flexible m e t a l flanges. I t
has a shelf life of one year a n d w i l l not properly cure
i f over age. Always inspect t h e package for t h e expi-
r a t i o n date before use.
DISASSEMBLY
Parts assembled w i t h form-in-place gaskets may be
disassembled w i t h o u t unusual effort. I n some i n -
stances, i t may be necessary t o l i g h t l y t a p t h e p a r t
w i t h a m a l l e t or other suitable tool to b r e a k the seal
between the m a t i n g surfaces. A flat gasket scraper
may also be l i g h t l y tapped i n t o the j o i n t b u t care
must be t a k e n not t o damage t h e m a t i n g surfaces.
SURFACE
PREPARATION
Scrape or w i r e brush a l l gasket surfaces t o remove
a l l loose m a t e r i a l . Inspect stamped parts t o ensure
gasket r a i l s are flat. F l a t t e n r a i l s w i t h a h a m m e r on
a flat plate, i f required. Gasket surfaces m u s t be free
of o i l and d i r t . M a k e sure t h e old gasket m a t e r i a l is
removed f r o m b l i n d attaching holes.
APPLICATION
Assembling parts using a form-in-place gasket re-
quires care. The R T V gasket m a t e r i a l should be ap-
plied i n a continuous bead approximately 3 m m (0.12
inch) i n diameter. A l l m o u n t i n g holes m u s t be cir-
cled. F o r corner sealing, a 1/8 or 1/4 i n c h drop is
placed i n the center of the gasket contact area. U n -
cured R T V may be removed w i t h a rag. Components
should be torqued i n place w h i l e the R T V i s s t i l l wet
to the touch ( w i t h i n 10 minutes). The usage o f a lo-
cating dowel is recommended d u r i n g assembly to pre-
vent smearing of m a t e r i a l off location.
Page
Measuring With Plastigage
5
Repair Of Damaged Or Worn Threads
6
ENGINE PERFORMANCE
To provide best vehicle performance and lowest ve-
hicle emissions, i t is most i m p o r t a n t t h a t the tune-up
be done accurately, u s i n g the specifications listed on
the
Vehicle
Emission
Control I n f o r m a t i o n label
found on the engine compartment hood.
(1) Test battery specific g r a v i t y . A d d water, i f nec-
essary. Clean and t i g h t e n battery connections.
(2) Test c r a n k i n g amperage d r a w (see Group 8B,
Battery/Starter Service for the proper procedures).
(3) T i g h t e n the i n t a k e m a n i f o l d bolts (see Group
1 1 , E x h a u s t System a n d I n t a k e M a n i f o l d for t h e
proper specifications).
(4) Perform cylinder compression test:
(a) Check engine o i l level a n d add o i l , i f neces-
sary.
(b) D r i v e the vehicle u n t i l engine reaches nor-
m a l operating temperature.
(c) Select a route free f r o m traffic and other
forms o f congestion, observe a l l traffic laws a n d
b r i s k l y accelerate t h r o u g h the gears several times.
The h i g h e r engine speed may help clean out valve
seat deposits w h i c h can prevent accurate compres-
sion readings.
CAUTION: Do not overspeed the engine.
(d) Remove a l l spark plugs from engine. A s
spark plugs are being removed, check electrodes for
abnormal f i r i n g indicators - fouled, hot, oily, etc.
Record cylinder number of spark p l u g for future
reference.
(e) Disconnect coil w i r e f r o m distributor and se-
cure t o good ground to prevent a spark from start-
i n g a fire.
(f) Be sure t h r o t t l e blades are fully open d u r i n g
the compression check.
(g) Insert compression gage adaptor into t h e
No. 1 spark p l u g hole. C r a n k engine u n t i l m a x i -
m u m pressure is reached on gauge. Record t h i s
pressure as No. 1 cylinder pressure.
(h) Repeat Step 4 g for a l l r e m a i n i n g cylinders.
(i) Compression should not be less t h a n 689
kPa (100 psi) and not v a r y more t h a n 172 kPa (25
psi) from cylinder to cylinder.
(j) I f one or more cylinders have abnormally
low compression pressures, repeat steps 4a t h r o u g h
4h.
(k) I f the same cylinder or cylinders repeat a n
abnormally low reading on the second compression
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