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explosion. Weakness in a valve spring can usually be detected by the following
method: Remove the plate which encloses them at the side of the cylinder and
insert a screw-driver between the coils of the spring while the engine is running.
If the extra tension thus produced causes the engine to pick up speed, the spring
is obviously weak and should be replaced with a new one.
What causes "Knocking"
in the Engine? Answer No. 28
There are several causes, which may be enumerated as follows: (1) carbon knock
—which is by far the most common resulting from carbonizing of cylinders; (2)
knock caused by a too advanced spark; (3) connecting rod knock; (4) crank shaft
main bearing knock; (5) knock due to loose-fitting piston or broken ring; (6)
knock caused by the piston striking the cylinder head gasket. When the engine
knocks from any cause whatsoever, the matter should be promptly investigated
by an experienced mechanic and the difficulty corrected.
How may the different
Knocks be distinguished? Answer No. 29
(1) The carbon knock is a clear, hollow sound, most noticeable in climbing sharp
grades, particularly when the engine is heated. It is also indicated by a sharp
rap immediately on advancing the throttle. (2) Too advanced spark will be indicated
by a dull knock in the motor. (3) The connecting rod knock sounds like the distant
tapping of steel with a small hammer, and is readily distinguished when the car
is allowed to run idly down grade —or upon speeding the car to twenty-five miles
an hour, then suddenly closing the throttle, the tapping will be very distinct.
(4) The crank shaft main bearing knock can be distinguished, when the car is
going uphill, as a dull thud. (5) The loose piston knock is heard only upon suddenly
opening the throttle, when the sound produced might be likened to a rattle. The
remedies for these knocks are treated under their proper division.
How is carbon removed from
Combustion Chamber? Answer No. 30
First, drain the water off by opening the pet cock at the bottom of the radiator;
then disconnect the wires at the top of the motor and also the radiator connection
attached to the radiator. Remove the 15 cap screws which hold the cylinder head
in place. Take off the cylinder head and, with a putty knife or screw-driver,
scrape the carbonized matter from the cylinder head and top of pistons, being
careful to prevent the specks of carbon from getting into the cylinders or bolt
holes. In re-placing the cylinder head gasket turn the motor over so that No.
1 and No. 4 pistons are at top center; place the gasket in position over the
pistons and then put the cylinder head in place. Be sure and draw the cylinder
head bolts down evenly (i. e., give each bolt a few turns at a time); do not
tighten them on one end before drawing them up at the other.
How are Spark
Plugs cleaned? Answer No. 31
After removing the plug from the engine the points may be cleaned with an old
tooth-brush dipped in gasoline. However, in order to do the work thoroughly,
the plug should be taken apart by securing the large hexagon steel shell in a
vise and loosening the pack nut which holds the porcelain in place. The carbon
deposits can then be easily removed from the porcelain and shell with a small
knife. Care should be exercised not to scrape off the glazed surface of the porcelain,
otherwise it will be apt to carbonize quickly. The porcelain and other parts
should finally be washed in gasoline and wiped dry with a cloth.
In assembling the plug care should be taken to see that the pack nut is not tightened
too much so as to crack the porcelain, and the distance between the sparking
points should be 32", about the thickness of a smooth dime.
Dirty plugs usually result from an excess of oil being carried in the crank case—or
from using oil of poor quality.
How is the Power Plant removed from Car?
(1) Drain the water out of the radiator and disconnect the radiator hose;
(2) disconnect the radiator stay rod which holds it to the dash;
(3) take out the two bolts which fasten the radiator to the frame and take
radiator off;
(4) disconnect the dash at the two supporting brackets which rest on the frame;
(5) loosen the steering post bracket, fastened to the frame, when the dash and
steering gear may be removed as one assembly —the wires first having been disconnected;
(6) take out the bolts holding the front radius rods in the socket underneath
the crank case;
(7) remove the four bolts at the universal joint;
(8) remove pans on either side of cylinder casting and turn off gasoline, disconnect
feed pipe from carburetor;
(9) disconnect exhaust manifold from exhaust pipe by unscrewing large brass pack
nut;
(10) take out the two cap screws which hold the crank case to the front frame;
(11) remove the bolts which hold the crank case arms to the frame at the side.
Then pass a rope through the opening between the two middle cylinders and tie
in a loose knot. Through the rope pass a "2x4," or a stout iron pipe
about ten feet long, and let a man hold each end; let a third man take hold of
the starting crank handle, when the whole power plant can be lifted from the
car to the work bench for adjustment.
Connecting Rod Bearings
—how adjusted? Answer No. 33
Connecting rod bearings may be adjusted, without taking out the engine, by the
following method: (1) drain off the oil; (2) remove plate on bottom of crank
case—exposing connecting rods; (3) take off first connecting rod cap, and draw-file
the ends—a very little at a time; (4) replace cap, being careful to see that
file marks correspond, and tighten bolts until it fits shaft snugly; (5) test
tightness of bearing by turning engine over by the starting handle. Experienced
mechanics usually determine when the bearing is properly fitted by lightly tapping
each side of the cap with a hammer; (6) then loosen the bearing and proceed to
fit the other bearings in the same manner; (7) after each bearing has been properly
fitted and tested—then tighten the cap bolts and insert cotter pins and the work
is finished.
Remember, there is a possibility of getting the bearings too tight, and under
such conditions the babbitt is apt to cut out quickly, unless precaution is taken
to run the motor slowly at the start. It is a good plan after adjusting the bearings
to jack up the rear wheels and let the motor run slowly for about two hours (keeping
it well supplied with water and oil) before taking it out on the road. Whenever
possible these bearings should be fitted by an expert Ford mechanic.
Worn connecting rods may be returned, prepaid, to the nearest dealer or branch
house for exchange at a price of $0.60 each to cover the cost of rebabbitting.
It is not advisable for any owner or repair shop to attempt the rebabbitting
of connecting rods or main bearings, for without a special jig in which to form
the bearings,
Answer No. 32