Piston and Piston Rings 1.6
DETROIT DIESEL 53
d. Ream the bushings (Fig. 7). Turn the reamer in a
clockwise direction only, when reaming or with-
drawing the reamer. For best results, use only
moderate pressure on the reamer.
e. Withdraw the reamer and remove the piston from
the fixture. Blow out the chips and measure the
inside diameter of the bushings. The diameter
must be 1.3775" to 1.3780".
Measure the piston skirt diameter lengthwise and
crosswise of the piston pin bore. Measurements should
be taken at room temperature (70o F.). The taper and
out-of-round must not exceed .0005" . Refer to
Section 1.0 for piston diameter specifications.
A new cylinder liner has an inside diameter of
3.8752" to 3.8767" The piston-to-liner clearance,
with new parts, is ,0031" to .0068" (non-turbocharged
A maximum clearance of .010"(non-turbocharged
with used parts.
With the cylinder liner installed in the cylinder block,
hold the piston upside down in the liner and check the
clearance in four places 90o apart (Fig. 8).
Fig. 8 - Measuring Piston-to-liner Clearance
Use feeler gage set J 5438 to check the clearance. The
spring scale, attached to the proper feeler gage, is used
c. With the piston. fixture and reamer in alignment,
to measure the force in pounds required to withdraw
tighten the wing nuts securely.
the feeler gage.
Fig. 9 - Measuring Piston Ring Gap
Fig. 10 Measuring Piston Ring Side Clearance
SEC. 1.6 Page 5