Rotor; Rotor Bearing - Mazda RX-7 Service Manual

ENGINE
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I
Figure 10
N o t e : T h e m e a s u r i n g P o i n t f o r
t h e m i c r o m e t e r i s o n t h e i n n e r
side of the rubber seal groove.
A f t e r m e a s u r i n g , m a r k t h e
h o u s i n g F o r R t o d e n o t e t h e
front and rear sides.
Rotor.
1. Checks (to be done before clean'
i n g ) .
( 1 ) R o t o r c o n d i t i o n .
C h e c k f o r g a s l e a k a g e , a n Y
damage to the rotor, and the
s t a t e o f c o m b u s t i o n . F i n a l l Y ,
check for any marks that would
indicate the rotor had been
c o n t a c t i n g t h e s i d e o f t h e
h o u s i n g ; t h e s e m a r k s m a Y b e
found, in particular, in the area
o f t h e t i p o f t h e r o t o r .
(2) Internal gear.
C h e c k c a r e f u l l y f o r c r a c k s , e x -
t r e m e a b r a s i o n s , d e n t s , n i c k s
and scratches and other dam'
a g e t o t h e g e a r a n d t e e t h .
( C r a c k s w i l l s o m e t i m e s a P -
p e a r a r o u n d t h e s P r i n g P i n
h o l e a n d i n t h e s P r i n g P i n i t '
s e l f . )
2 . C l e a n i n g .
W h e n c l e a n i n g t h e r o t o r , d o n o t
u s e a s t o n e , s a n d P a P e r , a n Y t o o l
or abrasives to remove carbon
from the apex seal groove. This
Figure 11
g r o o v e s h o u l d b e c l e a n e d o n l Y
with a brush and kerosene or MEK.
3 . M e a s u r e m e n t s .
( 1 ) U s i n g a 5 0 - 7 5 m m m i c r o m e t e r ,
measure the rotor at the three
p o i n t s s h o w n i n F i g u r e 1 1 .
( 2 ) C a l c u l a t e a R b y t h e f o l l o w '
i n g f o r m u l a :
A R = ( R o t o r h o u s i n g w i d t h
at point A) - (Max. rotor width
a t a n y p o i n t m e a s u r e d i n t h i s
step)
T h e a l l o w a b l e r a n g e o f a R i s
0 . 1 3 - 0 . 1 7
m m .
( 3 ) M e a s u r e m e n t o f a H .
T h i s m e a s u r e m e n t r e q u i r e s a
straightedge and a set of feel'
er gauges. Check it as shown
i n F i g u r e 1 2 . T h e a l l o w a b l e
r a n g e o f a H i s 0 . 1 5 - 0 . 2 0
m m .
Figure 12
F. Rotor bearing.
1 . C h e c k s .
Look for abnormal abrasions or
a n y s i g n s o f f l a k i n g o r s e i z i n g .
2 . M e a s u r e m e n t s .
( ' l ) M e a s u r e t h e b e a r i n g w i t h t h e
f o l l o w i n g P r o c e d u r e :
a ) U s e a n i n s i d e m i c r o m e t e r
and measure the bearing at
t h e s i x ( 6 ) p o s i t i o n s s h o w n
i n F i g u r e s 1 3 a n d 1 4 .
E.
Figure 13
1 6