Checking Engine Timing - TM-55-1905-221-14-30327

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GEAR TRAIN A ND ENGINE TIMING (Continued)

TM-55-1905-221-14-3 Landing Craft Mechanized Steel DED Overall Length 74 Feet Mod 1 Mark VIII Navy Design LCM-8 Manual

Checking Engine Timing-cont.

TM 55-1905-221-14-3

6-23.1.

GEAR TRAIN AND ENGINE TIMING (Continued).

An engine which is "out of time" may result in pre-ignition, uneven running and a loss of power.

When an engine is suspected of being out of time, due to an improperly assembled gear train, a quick check can be

made without having to remove the flywheel and flywheel housing by following the procedure outlined below.

d. Checking Engine Timing.

Access to the vibration damper or crankshaft pulley, to mark the top-dead-center position of the selected piston, and

to the front end of the crankshaft or flywheel for barring the engine over is necessary in performing the timing check.

Then, proceed as follows:

(1)

Remove the cylinder head rocker cover.

(2)

Select any cylinder for the timing check -- it is suggested that a cylinder adjacent to one of the cylinder

head cover studs be chosen since the stud may be used for mounting a dial indicator.

(3)

Remove the fuel lines (at the cylinder selected) and install shipping caps on injector fuel fittings to prevent

the entry of dirt. Make sure that the valve and injector rocker arms are all in the "up" position, then remove

the rocker shaft bracket bolts and swing the rocker arm assemblies back out of the way. Remove the

injector assembly.

(4)

Carefully place (do not drop) a rod approximately 12" long through the injector hole and on top of the

piston.

With the throttle in the NO FUEL position, turn the crank- shaft slowly in the direction of rotation of the

engine, and stop when the rod reaches the end of its upward travel. Remove the rod and turn the

crankshaft opposite the direction of rotation between 1/16 and 1/8 of a turn.

(5)

Select a dial indicator with .001" graduations and with a spindle movement of at least 1". Use suitable

mounting attachments for the indicator so that it can be mounted over the injector hole in the cylinder

head. Provide an extension for the spindle of the indicator. The extension must be long enough to contact

the piston as it approaches its upper position.

(6)

Mount the indicator over the injector hole and tighten mountings sufficiently to hold the indicator rigid.

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