Superior Vantage Engine O-360 SERIES Maintenance Manual page 38

−
Gap spark plugs to .016" - .021".
Projected nose massive spark plugs
can be gapped until the electrodes
are worn to a point where it becomes
difficult to properly adjust the gap.
Adjustment should be limited when
gapping fine-wire spark plugs. The
iridium material is very brittle. Using
small needle-nose pliers, grasp the
side wire perpendicular to the face of
the plug.
smoothly twist the pliers to achieve
the proper gap.
Never bend the center electrode or
apply pressure
electrode while setting the gap.
−
If desired, sparingly apply anti-seize
compound to all but the last thread of
spark plug.
−
Reinstall by switching spark plugs from
the top of the cylinder to the bottom and
bottom to top. Reinstall using a new
copper mounting gasket and a six-point
socket. Torque to 30-35 foot-pounds.
−
Reinstall ignition harness.
−
Never apply antiseize compound to the
harness connector threads.
−
Do not touch the spark plug connector or
harness spring
Contamination may cause arcing or
misfire.
−
Finger-tighten the harness connector "B"
nut. Hold 7/16" hex ferrule with wrench
to prevent lead rotation and tighten with
open-end wrench to 80-90 inch-pounds.
•
Cylinders
Visually check cylinders and baffling for
cracked or broken cooling fins, corrosion, oil
or fuel stains and visual damage.
•
Cylinder Compression Test
The purpose of
compression is to determine if any significant
leakage is occurring in the combustion
chamber due to
components. Typically leakage will occur
either past the valve seat or rings.
principle of a
© March 2006 Superior Air Parts Inc.
Maintenance Manual
O-360 and IO-360 Series Engines
One wire at a time,
to the ground
with fingers.
testing a cylinder's
worn or damaged
The
differential pressure
compression test is that for a given airflow
through a fixed orifice, a constant pressure
drop will occur across the orifice. The orifice
used for this test has a .04 inch diameter, .25
inch long with a 60° approach angle.
Following is the procedure for a differential
pressure compression check.
−
The operating and maintenance records
of the engine should be reviewed.
Records of previous compression tests
are of assistance in determining the
progressive wear conditions and help to
establish the necessary maintenance
actions.
compression check, precautions should
be taken to prevent the accidental
starting of the engine.
−
Perform the compression test as soon as
possible after the engine is shut down to
ensure that the piston rings, cylinder
walls, and other engine parts are well
lubricated.
−
With the air valve closed, apply an
external
(approximately 100 to 120 PSI) to the
tester.
−
Repeat the following for each cylinder
being tested:
Remove the most accessible spark
plug from the cylinder being tested.
Install the adapter in the spark plug
hole and connect the compression
tester to the cylinder.
Adjust the pressure regulator to
obtain a reading of 80 PSI on the
regulator pressure gauge.
time, the cylinder pressure gauge
should also register 80 PSI.
Turn the crankshaft by hand in the
direction of rotation until the piston
(in the cylinder being checked) is
coming
stroke.
and
approximately 20 PSI.
Continue rotating the engine against
this pressure until the piston reaches
top dead center (TDC).
TDC is indicated by a sudden
decrease in force required to turn the
crankshaft.
rotated too far, back up at least one-
half revolution and start over again
4
Scheduled Inspection and Maintenance
Before beginning
source of clean
up on its compression
Slowly open the air valve
pressurize the cylinder
Reaching
If the crankshaft is
05-20-00
a
air
At this
to