Figure 5-28. Methods of Cylinder Bore Inspection (Model RMPJ/1-10G)

TM 5-4110-217-14

not the cylinder is out of round. If the out of round

exceeds 0.005 Inch, the cylinders must be rebored and

honed for the next oversize piston. A reboring machine

is used when going to oversize pistons.

5-29. Cylinder Block Repair.

a. hone can be used to rebore a cylinder (figure 5-

29). Remove stock to 0.002 inch undersize of finish bore

with course hone (100 grit), then complete honing with

finish hones (300 grit),

b. Anchor the block solidly for either vertical or

horizontal honing. Use either a drill press or heavy duty

drill which operates at approximately 250 to 450 rpm.

c. Lower the hone into the cylinder until it protrudes

1/2 to 3/4 inch past the end of the cylinder.

Rotate the adjusting nut until the stones come in

contact with the cylinder wall at the narrowest point.

d. Turn the hone by hand. Loosen the adjusting

nut until the hone can be turned.

e. Connect drill to hone and start drill. Move the

hone up and down In the cylinder approximately 40

cycles per minute. Usually the bottom of the cylinder

must be worked out first because it is smaller. Then

when the cylinder takes a uniform diameter, move the

one up and down all the way through the bore. Follow

the hone manufacturer's recommendations for wet or dry

honing and oiling the hone.

f. Check the diameter of the cylinder regularly

during honing. A dial bore gauge is the easiest

Figure 5-28. Methods of Cylinder Bore Inspection (Model

RMPJ/1-10G)

(4) Measure and record as "D" the diameter at

the bottom of the cylinder bore and crosswise of the

block.

(5) Reading "A" compared to reading "B" and

reading "C" compared to reading "D" indicates cylinder

taper.

(6) If cylinder taper exceeds ;.005 inch, rebore

and hone to accommodate the next oversize piston.

Figure 5-29. Honing Cylinder (Model RMP-J/1-1OG

Reading "A" compared to reading "C" and reading "B"

compared to reading "D" indicates whether or.

5-18