Mazda RX-7 - Apex Seal

ENGINE
G.
f)
Slightly scrape and smooth
the surface over the screw.
g)
Clean
the rotor thoroughly
with kerosene
and
blow
clean and dry with
air.
Apex seal.
1.
Checks.
Basically,
the seal should be
visu-
ally
checked for
wear,
chipping in
the
groove,
cracks, and any other
irregularities.
2. Cleaning.
Remove the carbon with
MEK
or
paint
thinner.
3. Measurements.
(1)
Measure
height, length and
width
as
shown in Figure 18.
This will require two
microme-
ters,
a 0-25
mm
and
a
50-75
mm.
Mark each apex seal
to
denote
its
position
and
loca-
tion on the
rotor.
Measure as
follows:
a) Height A at both
ends.
b)
Length B
at
one
point.
c) Width C at both ends.
Figure
18
(2)
Measurement
of
a S,
the
clearance
between
the
aPex
seal and
the side
housing.
a) This
measurement
requires
a 50-75
mm
micrometer.
b) Calculate
a
S
by
the fol-
lowing formula:
A
S
=
(Rotor
housing
width
at
point
A)
(Apex
seal
length)
The allowable
range
of a S
is
0.10
-r
0.01
mm.
Note:
The
rebuildable
limit
of
AS
is 0.15
mm.
(3)
Adjusting aS.
lf a S is less than the
lower
limit of
the allowance,
it
can
be adjusted by sanding
the
end of the apex seal
with
#400-#600
sandpaper,
as
shown
in
Figure 19.
Note:
Be careful
not
to
remove
too much material
from the
apex
seal, thereby
increasing
the
clearance
over
limits
which
would
necessitate replacing
the
seal.
Figure 19
Measurement of
a
G,
the
gap
between
the
apex seal and
the
apex
seal
groove.
This
measurement requires
a
feeler
gauge,
and
is
done
as
shown
in Figure 20.
The
allowable
limit of
A
G
is
0.065
-r
0.005
mm.
Note: lf A G
is in the range
of
0.06-0.07
mm, the
0.06
gauge
will easily
fit into the
groove;
the 0.07
gauge
will be
very
tight.
(4)
18