CHRYSLER SERVICE MANUAL
ENGINE—25
of-round and taper with Tool CM-119. If cyl-
inder bores show more than .005 inch
out-of-
round or a taper of more than .010 inch, the
cylinder block should be rebored and new pis-
tons and rings fitted.
b.
Honing Cylinder Bores
To remove light scoring, scuffing, or scratches
from cylinder walls, use honing Tool C-823.
The crankshaft, bearings and internal parts
should be protected during honing and boring
operations. Usually one or two "passes" with
a hone will clean up a bore and still maintain
required limits. If cylinder bores are found to
be satisfactory in respect to taper and
out-of-
round and new rings are to be installed, use
cylinder surfacing hone Tool C-3501 with 280
grit stones for deglazing bores. This will facili-
tate in the break-in of new rings.
CAUTION
Be sure all abrasives are removed from engine
parts after honing. It is recommended that a
solution of soap and water be used with a brush
and then thoroughly dried. If this is impossible
use SAE No. 10 oil and CLEAN rags. When the
bore can be wiped with a clean white rag and
be withdrawn clean, the bore is clean.
c. Cylinder Walls
Cylinder walls which are badly scored, scuffed,
scratched, or worn beyond specified limits
should be rebored. Whatever type of boring
equipment is used, boring operation should be
closely co-ordinated with the fitting of pistons
and rings, in order that specifications may be
maintained.
SPRING SCALE (TOOL)
INVERTED PISTON
57x225
Fig.
42—Checking Ring Gap in Cylinder Bore (FirePower)
(Typical of SpitFire)
d. Fitting Pistons
The piston and cylinder wall must be clean
and dry. Coat the bore very lightly with SAE
10 W Engine Oil. The recommended clearance
between the thrust face of piston and cylinder
wall is .005 to .0015 inch. Check clearance with
a .002 inch feeler stock
y%
inch wide on spring
scale Tool C-690, by inserting piston in bore,
upside down, with feeler stock between thrust
face of piston and cylinder wall. Hold piston
and draw the feeler stock straight out with
spring scale (Fig. 41). The amount of pull re-
quired to withdraw the feeler stock should be
8 to 12 pounds.
NOTE:
Piston fitting should be done at normal
room temperature, 70° F.
All service pistons include piston pins and
retaining rings and are available in standard
PISTON RING
RING GROOVE
57x224
Fig.
41—Fitting Piston to Cylinder Bore (FirePower)
(Typical of SpitFire)
57x226
Fig.
43—Checking Piston Ring Side Clearance
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