Chrysler PT Cruiser Service & Repair Manual page 1060

9 - 40 ENGINE 1.6L SOHC
VALVE SPRINGS AND SEALS (CYLINDER HEAD REMOVED) (Continued)
ENGINE - SPECIFICATIONS). Replace springs that
do not meet specifications.
Fig. 51 Testing Valve Spring
1 - SPECIAL TOOL C-647
INTAKE/EXHAUST VALVES &
SEATS
STANDARD PROCEDURE - VALVE AND VALVE
SEAT REFACING
For all applicable valve and seat dimensions and
angles (Refer to 9 - ENGINE - SPECIFICATIONS).
(1) Reface valves using a suitable valve refacing
machine.
(2) Inspect the remaining margin after the valves
are refaced (Fig. 52). Intake valves with less than
0.79 mm (0.0312 in.) margin and exhaust valves with
less than 1.19 mm (0.0469 in.) margin should be
replaced.
Fig. 52 Intake and Exhaust Valve Refacing
1 - VALVE FACE
2 - VALVE MARGIN
(3) Valve seats which are worn or burned can be
reworked, provided that correct angle and seat width
are maintained. Otherwise the cylinder head must be
replaced.
(4) Reface valve seats using a suitable valve seat
machine
(5) When refacing valve seats, it is important that
the correct size valve guide pilot be used for reseat-
ing stones or cutter. A true and complete surface
must be obtained.
(6) Measure the concentricity of valve seat and
valve guide using a valve seat runout dial indicator.
Total runout should not exceed. 0.051 mm (0.002 in.)
(total indicator reading).
(7) Inspect the valve seat with Prussian blue to
determine where the valve contacts the seat. To do
this, coat valve seat LIGHTLYwith Prussian blue
then set valve in place. Rotate the valve with light
pressure. If the blue is transferred to the center of
valve face, contact is satisfactory. If the blue is trans-
ferred to top edge of the valve face, lower valve seat
with a 15 degrees stone/cutter. If the blue is trans-
ferred to the bottom edge of valve face raise valve
seat with a 65 degrees stone/cutter.
(8) When seat is properly positioned the width of
intake and exhaust seats should be 0.75–1.25 mm
(0.029–0.049 in.) (Fig. 53).
Fig. 53 Valve Face and Seat
1 - SEAT WIDTH
2 - FACE ANGLE
3 - SEAT ANGLE
4 - SEAT CONTACT AREA
(9) Check valve tip to cylinder head surface dimen-
sions after machining the valve seats or faces. Grind
valve tip until within specifications. Measure from
valve tip to cylinder head surface when valve is
installed in the head (measurement A) (Fig. 54). For
valve tip specifications, (Refer to 9 - ENGINE -
SPECIFICATIONS). The valve tip chamfer is needed
to be reground to prevent seal damage when the
valve is installed.
(10) Measure valve spring installed height (mea-
surement B) (Fig. 54). Measure from the top of the
valve spring seat/seal to the bottom of the valve
spring retainer. For valve spring installed height
specifications, (Refer to 9 - ENGINE - SPECIFICA-
TIONS).
PT