Cleaning.

TM 10-3930-673-34

b. Cleaning.

CAUTION

Do not clean cylinder block in an acid bath unless camshaft bushing has been removed.

An acid bath can severely damage camshaft bushing.

(1)

Soak cylinder block (3) in an acid bath if camshaft bushing (1) has been removed and if

heavy deposits exist in coolant passages.

(2)

If camshaft bushing (1) has not been removed and coolant passages have heavy deposits,

soak cylinder block in a solution of hot water and laundry detergent. Maintain water

temperature of 190F (88C) and allow cylinder block to soak for a period of 30 minutes.

(3)

Following cleaning by either method (Step (1) or (2)), rinse thoroughly with clean, fresh

water and allow surface to dry completely.

(4)

If a sizing hone is used to correct a minor cylinder bore taper or to remove minor

grooves in cylinder walls, immediately clean bores using a strong solution of laundry

detergent and hot water. Rinse thoroughly with clear water.

(5)

After rinsing and drying cylinder bores, wipe bores with white, lint-free cloth that is

lightly oiled. If grit residue is present on cloth, clean bores again in detergent solution.

c. Inspection.

(1)

Check flatness of cylinder block (3) top surface.

(a)

Place a straightedge along length of cylinder block top.

(b)

Measure gap under straightedge in area between cylinders (five measurements, total) using a

feeler gauge.

(c)

Maximum allowable variation between any two of the five measurements is 0.002 in.

(0.05 mm).

(2)

Inspect cylinder bores.

(a)

Visually inspect all bores for excessive glazing. Deglaze cylinder bores, as required.

NOTE

A properly deglazed cylinder bore surface will have a crosshatched appearance with lines

at angles from 15 to 25 with respect to top of cylinder block. Included angles on

crosshatch will be from 30 to 50.

(b)

Measure diameter of each cylinder bore, from a point l in. (25.4 mm) below top of cylinder

block to a point 5.5 in. (139.7 mm) below top of cylinder block.

(c)

Minimum allowable diameter is 4.0157 in. (102 mm).

(d)

Maximum allowable diameter is 4.0203 in. (102.12 mm).

(e)

Maximum allowable taper is 0.003 in. (0.08 mm).

(f)

Maximum allowable out-of-roundness is 0.0015 in. (0.04 mm).

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