Wisconsin VH4D Dokumentacja Pobierz pdf (Strona 27)

VALVE LIFTER

RETAINER

F ig. 33

.007", the guides should be driven out and replaced

with new guides.

These engines that have Stellite exhaust valves and

inserts are designated as Model VH4D and are equip-

ped with positive type exhaust valve rotators. The

action of the rotocap, which rotates the valve slightly

each time the valve opens, helps prevent sticky valve

and will impart a wiping action between the valve

face and valve seat, thereby preventing the build-up

of foreign deposits. Valve rotation will also avoid

prolonged exposure of any one sector of the valve

face to a local hot spot on the seat which will result

in lower and more uniform valve face-seat tempera-

tures.

CRANKSHAFT

To remove the crankshaft, first remove the six cap-

screws in the main bearing plate at the take-off end

of the engine. This plate can then be pried off, and

crankshaft removed from that end of crankcase. See

Fig. 34. Be sure to keep shims and gaskets in place

as these are necessary to give the proper end play to

Fig. 34

the tapered roller main bearings on the crankshaft.

This end play should be .002 to .004 inch when en-

gine is cold. There is practically no wear in these

bearings so that no readjustment is necessary after

proper assembly.

When reassembling crankshaft, the timing marks on

the crankshaft gear and the camshaft gear must be

matched as shown in Fig. 24, otherwise engine will

not operate properly, or if timing is off considerably,

engine will not run at all.

The mounting holes for the main bearing plate are

off-set in such a manner that it can only be mounted

in the correct position. Tighten main bearing plate

capscrews, 25 to 30 foot pounds torque.

CAMSHAFT

The camshaft must be withdrawn from the flywheel

end of the engine as shown in Fig. 35. When reassem-

bling, be sure the spring and plunger are in place in

the end of the camshaft, as they hold the camshaft

in position endwise. These parts are shown in the

sectional view of the engine, Fig. 2.

VALVE TAPPETS

The valve tappets are taken out after the camshaft is

removed. In reassembly, the tappets must of course

be inserted in proper position in crankcase, before

the camshaft is assembled.

After the cylinder blocks have been assembled to the

crankcase, adjust the valve tappets as shown in Fig.

36. With the tappets in their lowest positions, engine

cold, the clearance should be .008 inch for the inlet

and .0|6 inch for the exhoust, with or without Stellite

valves.

GOVERNOR - OPERATION

The centrifugal flyball governor rotates on a station-

ary pin driven into the upper part of the timing gear

BOLT

CAMSHAFT

PULL VALVE TAPPETS

IN OUTWARD

DIRECTION

Fig. 35

1 2 ... 22 23 24 25 26 27 28 29 30 31 32 ... 47 48

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Wisconsin VH4D Dokumentacja Strona 27

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