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worth & Co. (A), provide an eccentric sleeve adjustment for the magneto shaft giving a maximum of 6 millimeters lateral displacement. Gregoire (B), uses two eccentric sleeves, so that up or down movement of the pinion can be avoided, probably with a view to leaving the valve timing entirely unaffected.

Chenard-Walcker (C), pushes the whole sprocket pinion bearing as well as the baseplate of the magneto outwardly in a recti

B

A

C

[graphic]

Fig. 162.—How Silent Chains may be Adjusted for Wear.

QUTER ECCENTRIC

BUSHING

MOVABLE
PLATE

11

ECCENTRIC BŪSHING

INNER ECCENTRIC

BUSHING

linear movement by means of a drawbolt, locking the adjustment with setscrews.

The method used on the King engines of this form is clearly shown in accompanying front view of the motor with timing gear case cover removed. A pinion mounted on a slotted plate which is adjustable can be moved to take out any slack in the chain as desired.

Precautions in Reassembling Parts.- When all of the essential components of a power plant have been carefully looked over and cleaned and all defects eliminated, either by adjustment or replacement of worn portions, the motor should be reassembled, taking care to have the parts occupy just the same relative posi

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Fig. 163.—Diagrams Showing Movements of the Piston for Different Positions of the Crankshaft in Eight

Cylinder V Motor.

[graphic]
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Note Method

Fig. 164.–Front View of King Eight Cylinder Motor.

of Camshaft Drive Chain Adjustment.

tions they did before the motor was dismantled. As each part is added to the assemblage care should be taken to insure adequate lubrication of all new points of bearing by squirting liberal quantities of cylinder oil upon them with a hand oil can or syringe provided for the purpose. In adjusting the crankshaft bearings tighten them one at a time and revolve the shafts each time one of the bearing caps is set up to insure that the newly adjusted bearing does not have undue friction. All retaining keys and pins must be positively placed and it is good practice to cover such a part with lubricant before replacing it because it will not

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Fig. 165.—Longitudinal Part Sectional View of King Eight Cylinder

Motor, Showing Important parts.

only drive in easier but the part may be removed more easily if necessary at some future time. If not oiled, rust collects around it.

When a piece is held by more than one bolt or screw, especially if it is a casting of brittle material such as cast iron, the fastening bolts should be tightened uniformly. If one bolt is tightened more than the rest it is liable to spring the casting enough to break it. Spring washers, check nuts, split pins or other locking means should always be provided, especially on parts which are in motior or subjected to a load. Before the cylinders are replaced on the engine base, heavy brown paper gaskets should be made to piace between the cylinder base flange and top portion of the engine crank case. The best method of making these gaskets is to tamp them out by placing the sheet of brown paper over the mouth of the cylinder and directing a series of light blows with a machinists' ball peen hammer against the sharp edges of the casting. This will cut the paper exactly to the form of the base flange and cylinder bore. The holes in the flange may be indicated in the same manner or may be punched through with a steel drift. The same process may be used in making irregular shape gaskets of other materials such as asbestos or rubber packing.

Before placing the cylinder over the piston it is imperative that the slots in the piston rings are spaced equidistant and that the piston is copiously oiled before the cylinder is slipped over it. When reassembling the inlet and exhaust manifolds it is well to use only perfect packings or gaskets and to avoid the use of those that seem to have hardened up or flattened out too much in service. If it is necessary to use new gaskets it is imperative to employ these at all joints on a manifold because if old and new gaskets are used together the new ones are apt to keep the manifold from bedding properly upon the used ones. It is well to coat the threads of all bolts and screws subjected to heat, such as cylinder head and exhaust manifold retaining bolts with a mixture of graphite and oil. Those that enter the water jacket should be covered with white or red lead or pipe thread compound. Gaskets will hold -better if coated with shellac before the manifold or other parts are placed over them. The shellac fills any irregularities in the joint and assists materially in preventing leakage after the joint is made up and the coating has a chance to set.

In replacing cylinder head packings on cars like the Ford, it is well to run the engine for a short while, several minutes at the most, without any water in the jacket in order to heat the head up thoroughly. It will usually be found possible to tighten down a little more on all of the cylinder head retaining bolts after this is done because if the gasket has been coated with shellac the 3u1 plus material will have hurnt off and the entire packing bedded

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