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open. If it is open the same amount as it was on the other end of the stroke, the valve is set correctly. The
valve should be opened the same amount on each end when the piston is at the respective ends of its stroke.
The lead is now divided equally.
6.
Tighten the lock nut on the valve stem and the process of setting the low-pressure valve is complete. To set
the high pressure, the same method is followed, using the low-pressure counter-weight to find the dead
center for the high-pressure piston. Usually the lead is between one thirty-second and one sixteenth of an
inch. This method is an approximate one, used by road repairmen, but is sufficiently accurate for all practical
purposes.
DIRECTIONS FOR VALVE SETTING ON THE NEW TYPE ENGINES
1.
Have the valve stem screwed down as nearly the proper position as possible. The valve on the new type of
engine is an inside admission valve. The steam edge of the valve is on the inside and not at the end, as on the
older type engines. Therefore, the valve setting will be done by inside edges. The position of the valves can
be seen through holes in which the cylinder cocks are placed. These latter must be removed. Begin turning
the crankshaft slowly in a forward direction, at the same time rocking the reverse rocker arm on the engine
back and forth. At some point of the revolution of the crankshaft the valve stem will cease to move up and
down, while the reverse rocker arm is being moved back and forth. At this point the piston is at the end of its
stroke, and valve should be opened the amount of the lead. The same method of dividing the lead equally is
followed as in the older style engine. The principal differences are the method of finding the dead center of
the engine and the fact that the steam edges of the valve are on the inside. It is worth the trouble after having
tightened the lock nuts on the valve stem, to repeat the whole operation, and check the work done.
Occasionally in tightening the lock nut the valve stem is turned a little, causing the valve setting to be
slightly inaccurate.
In setting the pistons back in the cylinders, after having removed them, a certain position is necessary. The
figures given below represent the distance from the machined upper face of the cylinder to the piston head, the
crosshead being at the upper extremity of its stroke. This distance is termed by White mechanics "the piston
clearance," a term which is not exactly correct, however, as the true clearance would be between the piston head and
the cylinder head. The "Clearance" on the Models C and D is as follows: High-pressure, one-half inch; low-pressure,
seven-sixteenths. On Models E, F, H, and L, high-pressure, seven-sixteenths; low-pressure, three-eighths, On Models
G and K, high-pressure, eleven-sixteenths; low-pressure, five-eighths. On Model M and MM, high-pressure, seven-
eighths; low-pressure, seven-eighths. On Models O and OO, high-pressure, thirteen-sixteenths; low-pressure, thirteen-
sixteenths. After screwing the piston down to the proper Position, be sure that the lock nut is tightened snugly and that
the lock washer is turned up around the nut. If this nut loosens up there is enough motion in the threads to cause a
pound when the engine is pulling.
A leaky stuffing box is a good indication of a careless and inefficient driver. When stuffing boxes are packed
properly, the packing should be cut in lengths to make a closed ring around the piston rod. This was the method of
earlier days. Packing can now be procured put up in rings ready to go into the stuffing box. It is a good point to
lubricate the packing with oil and graphite when putting it in. Push as many pieces of the packing into the stuffing
box as can be gotten in with the fingers, taking care that the joint in one ring is on the opposite side of piston rod from
the joint in the ring which is just above it. When the box is filled, the packing nut should be screwed up as far as
possible. Then remove same and insert more packing, each time screwing up the nut and compressing the packing
already in place. A common mistake is in having the last ring of packing loose enough at the end to catch under the
gland. In this case the gland appears to be tight, but does not compress the packing, and a steam leak is sure to follow,
no matter how tightly the nut is screwed up. The causes for leaking stuffing boxes will be taken up under the proper
head in connection with the charts.
In order to properly drain the water from the car when getting it ready for storage or for shipment in cold
weather, it should be done while the car is hot.
1.
Run the engine long enough to get the car heated fairly up to its maximum temperature, approximately half
an hour, with condenser drain cock open.
DIRECTIONS FOR SETTING PISTON
DIRECTIONS FOR PACKING STUFFING BOXES
TO DRAIN THE CAR FOR STORAGE OR SHIPPING
10
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