Transcript Engine Measuring

Engine Measuring
Vernier (Dial) Caliper
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Useful because it
can read inside
and outside
measurements.
Use only as a
“rough” guide.
Add the reading
on the blade to
the reading on the
dial.
Micrometer
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The most used
measuring instrument
in engine service and
repair
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Each revolution of the
thimble moves the
spindle .025”.
The thimble is graduated
into 25 equally spaced
lines so ….
Each line represents
.001”
Crankshaft Measurement
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Measure for out-of-round
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Measure the journal in at least six different
positions across the diameter at 60 degree
increments. This should be done at the same
horizontal position.
Subtract the highest from the lowest to factor outof-round.
Crankshaft Measurement
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Crankshaft taper – measure the journal at
two different horizontal positions across the
journal and subtract to factor taper.
Telescopic Gauge
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Used in conjunction
with a micrometer to
determine the inside
diameter of a hole.
The gauge is inserted
until contact is present
and then locked.
A micrometer is then
used for measurement.
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Use only if necessitated.
Small (split)-ball Gauge
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Similar to a
telescopic gauge
in that it is used
in conjunction
with a
micrometer to
determine the
inside diameter
of a hole.
Small (split)-ball Gauge
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The gauge is
inserted until contact
is present and then
locked.
A micrometer is then
used for
measurement.
Used for small
bores.
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example: valve
guide
Split-ball Probe
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More accurate than a
split ball gauge
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Often used for larger
bores
Feeler Gauge
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An accurately
manufactured strip of
metal used to factor the
gap or clearance
between two
components.
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Used for:
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Piston ring gap
Piston ring side
clearance
Connecting rod side
clearance
Warpage
Straightedge
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A precision
ground metal
used to check to
flatness of a
component. Used
for:
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Cylinder heads
Block deck
Dial Indicator
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Measures
variations from
zero. 14-21
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Used to check
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Runout
Crankshaft
endplay
Valve guide
wear
Dial Bore Gauge
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The most accurate way
to measure bore
diameter, taper or outof-round.
Gauge must be “set-up”
and zeroed before
usage.
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Used for:
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Cylinders
Main bores
Connecting rod bores
Bearing bores