Chapter L: Appendix: I (1)

FORD--MODEL-T

THE CAR, ITS OPERATION, AND CARE

Given in Questions and Answers--This Supplement also Covers the 1-Ton Truck

_Q._ What should be done before starting the car?

_A._ Before trying to start the car fill the radiator (by removing the cap at the top) with clean fresh water. If perfectly clean water cannot be obtained, it is advisable to strain it through muslin or other similar material to prevent foreign matter from getting in and obstructing the small tubes of the radiator. The system will hold approximately three gallons of water. It is important that the car should not be run under its own power unless the water circulating system has been filled. Pour in the water until you are sure that both radiator and cylinder water jackets are full. The water will run out of the overflow pipe onto the ground when the entire water system has been properly filled. During the first few days that a new car is being driven it is a good plan to examine the radiator frequently and see that it is kept well filled. The water supply should be replenished as often as it is found necessary to do so. Soft rain water, when it is to be had in a clean state, is superior to hard water, which may contain alkalies and other salts which tend to deposit sediment and clog the radiator.

_Q._ What about gasoline?

_A._ The ten gallon gasoline tank should be filled nearly full and the supply should never be allowed to get low. Strain the gas through chamois skin to prevent water and other foreign matter from getting into the tank. Dirt or water in the gasoline is sure to cause trouble. When filling the tank be sure that there are no naked flames within several feet, as the vapor is extremely volatile and travels rapidly. Always be careful about lighting matches near where gasoline has been spilled, as the air within a radius of several feet is permeated with the highly explosive vapor. The small vent hole in the gasoline tank cap should not be allowed to get plugged up, as this would prevent proper flow of gasoline to the carburetor. The gasoline tank may be drained by opening the pet cock in the sediment bulb at the bottom of the tank.

_Q._ How about the oiling system?

_A._ Upon receipt of the car see that a supply of medium light high-grade gas engine oil is poured into the crank case through the breather pipe at the front of the engine (a metal cap covers it). Down under the car in the flywheel casing (the reservoir which holds the oil) you will find two pet cocks. Pour oil in slowly until it runs out of the upper cock. Leave the cock open until it stops running, then close it. After the engine has become thoroughly warmed up, the best results will be obtained by carrying the oil at a level midway between the two cocks, but under no circumstances should it be allowed to get below the lower cock. All other parts of the car are properly oiled when it leaves the factory. However, it will be well to see that all grease cups are filled and that oil is supplied to the necessary parts. (See chapter on Lubrication.)

_Q._ How are spark and throttle levers used?

_A._ Under the steering wheel are two small levers. The right hand (throttle) lever controls the amount of mixture (gasoline and air) which goes into the engine. When the engine is in operation, the farther the lever is moved downward toward the driver (referred to as “opening the throttle”) the faster the engine runs and the greater the power furnished. The left hand lever controls the spark which ignites the gas in the cylinders of the engine. The advancing of this lever “advances the spark,” and it should be moved down notch by notch until the motor seems to reach its maximum speed. If the lever is advanced beyond this point a dull knock will be heard in the engine. (See chapter on Ignition.)

_Q._ Where should these levers be when the engine is ready to crank?

_A._ The spark lever should usually be put in about the third or fourth notch of the quadrant (the notched half circle on which the levers operate). The throttle should usually be opened five or six notches. A little experience will soon teach you where these levers should be placed for proper starting. Care should be taken not to advance the spark lever too far as the engine may “back-kick.”

_Q._ What else is necessary before cranking the engine?

_A._ First, see that the hand lever that comes up through the floor of the car at the left of the driver, is pulled back as far as it will go. The lever in this position holds the clutch in neutral and engages the hub brake, thus preventing the car from moving forward when the engine is started. Second, after inserting the switch key in the switch on the coil box, throw the switch lever as far to the left as it will go, to the point marked “magneto.” This switch connects the magneto to the engine. The engine cannot be started until it is on; and the throwing off of the switch stops the engine. The next step is to crank the engine.

_Q._ How is the engine cranked?

_A._ By the lifting of the starting crank at the front of the car. Take hold of the handle and push it toward the car until you feel the crank ratchets engage, then lift upward with a quick swing. With a little experience this operation will become an easy matter. Do not as a usual thing crank downward against the compression, for then an early explosion may drive the handle vigorously backward. This does not mean, however, that it is advisable, when the car is hard to start, to occasionally “spin” the engine with the starting handle but be sure that the spark is retarded when spinning or cranking the engine against compression, otherwise a sudden back-fire may injure the arm of the operator. When the engine is cool it is advisable to prime the carburetor by pulling on the small wire at the lower left-hand side of the radiator while giving the engine two or three quarter turns with the starting handle.

_Q._ How is the engine best started in cold weather?

_A._ As gasoline does not vaporize readily in cold weather, it is naturally more difficult to start the motor under such conditions. The usual method of starting the engine when cold is to turn the carburetor dash adjustment one-quarter turn to the left in order to allow a richer mixture of gasoline to be drawn into the cylinders. Then hold out the priming rod which projects through the radiator while you turn the crank from six to eight quarter turns in quick succession. Another method of starting a cold troublesome motor is as follows: Before you throw on the magneto switch, (1) close throttle lever. (2) Hold out the priming rod while you crank several quick turns, then let go of the priming rod, being careful that it goes back all the way. (3) Place spark lever in about the third notch and advance throttle lever several notches. (4) Throw on switch being sure to get it on the side marked “magneto.” (5) Give crank one or two turns and the motor should start. After starting the motor it is advisable to advance the spark eight or ten notches on the quadrant and let the motor run until it is thoroughly warmed up.

If you start out with a cold motor you will not have much power and are liable to “stall.” The advantage of turning on the switch last, or after priming, is that when you throw on the switch and give the crank one-quarter turn you have plenty of gas in the cylinders to keep the motor running, thereby eliminating the trouble of the motor starting and stopping. After motor is warmed up turn carburetor adjustment back one-quarter turn.

_Note._ Many drivers make a practice of stopping their engine by walking around in front of the car and pulling out on the priming rod which has the effect of shutting off the air suction and filling the cylinders full of a very rich gasoline vapor. This should not be done unless the car is going to stand over night or long enough to cool off. If the motor is stopped in this way and then started when hot, starting is apt to be difficult on account of the surplus gasoline in the carburetor.

_Q._ How do the foot pedals operate?

_A._ The first one toward the left operates the clutch, and by it the car is started and its operations largely controlled. When pressed forward the clutch pedal engages the low speed gear. When halfway forward the gears are in neutral (i. e., disconnected from the driving mechanism of the rear wheels), and, with the hand lever thrown forward the releasing of the pedal engages the high-speed clutch. The right hand pedal operates the transmission brake.

_Q._ What function does the hand lever perform?

_A._ Its chief purpose is to hold the clutch in neutral position. If it were not for this lever the driver would have to stop the engine whenever he left the driver’s seat. He would also be unable to crank the engine without the car starting forward with the first explosion. When pulled back as far as it will go, the hand lever acts as an emergency lever on the rear wheels, by expanding the brake shoes in the rear wheel drums. Therefore the hand lever should be back as far as it will go when cranking the engine or when the car is at rest. It should be only in a vertical position, and not far enough backward to act as a brake on the rear wheels when the car is to be reversed. When the car is operating in high or low speed the hand lever should be all the way forward.

_Q._ How is the car started?

_A._ Slightly accelerate the engine by opening the throttle. Place the foot on the clutch pedal, and thereby hold the gears in a neutral position while throwing the hand lever forward. Then to start the car in motion, press the pedal forward into low speed and when under sufficient headway (20 to 30 feet), allow the pedal to drop back slowly into high speed, at the same time partially closing the throttle which will allow the engine to pick up its load easily. With a little practice the change of speeds will be easily accomplished, and without any appreciable effect on the smooth running of the machine.

_Q._ How is the car stopped?

_A._ Partially close the throttle. Release the high speed by pressing the clutch pedal forward into neutral. Apply the foot brake slowly but firmly until the car comes to a dead stop. Do not remove the foot from the clutch pedal without first pulling the hand lever back to neutral position, or the engine will stall. To stop the motor, open the throttle a trifle to accelerate the motor and then throw off the switch. The engine will then stop with the cylinders full of gas, which will naturally facilitate starting.

Endeavor to so familiarize yourself with the operation of the car that to disengage the clutch and apply the brake becomes practically automatic, the natural thing to do in case of emergency.

_Q._ How is the car reversed?

_A._ It must be brought to a dead stop. With the engine running, disengage the clutch with the hand lever and press the reverse pedal forward with the left foot, the right foot being free to use on the brake pedal if needed. Do not bring the hand lever back too far or you will set the brakes on the rear wheels. Experienced drivers ordinarily reverse the car by simply holding the clutch pedal in neutral with the left foot, and operating the reverse pedal with the right.

_Q._ How is the spark controlled?

_A._ By the left hand lever under the steering wheel. Good operators drive with the spark lever advanced just as far as the engine will permit. But if the spark is advanced too far a dull knock will be heard in the motor, due to the fact that the explosion occurs before the piston in the engine has completed its compression stroke. The best results are obtained when the spark occurs just at the time that piston reaches its highest point of travel, the gas being then at its highest point of compression. The spark should only be retarded when the engine slows down on a heavy road or steep grade, but care should be exercised not to retard the spark too far, for when the spark is “late” instead of getting a powerful explosion, a slow burning of gas with excessive heat will result. Learn to operate the spark as the occasion demands. The greatest economy in gasoline consumption is obtained by driving with the spark advanced sufficiently to obtain the maximum speed.

_Q._ How is speed of car controlled?

_A._ The different speeds required to meet road conditions are obtained by opening or closing the throttle. Practically all the running speeds needed for ordinary travel are obtained on high gear, and it is seldom necessary to use the low gear except to give the car momentum in starting. The speed of the car may be temporarily slackened in driving through crowded traffic, turning corners, etc., by “slipping the clutch,” i. e., pressing the clutch pedal forward into neutral.

_Q._ Is it advisable for owners to make their own adjustments?

_A._ The Ford is the simplest of all cars. Most of the ordinary adjustments an owner will soon learn to make for himself. But we must strongly recommend that when it becomes necessary to employ the services of a mechanic, the car be taken to a Ford mechanic--one of our own representatives who thoroughly understands the car--and who will have no motive for running up useless repair bills. The entire Ford organization is interested in keeping every individual Ford car in constant operation, at the lowest possible cost. We have known of much damage done to many cars by unskilled repair men.

_Q._ What attention does the car need?

_A._ Remember that a new machine requires more careful attention during the first few days it is being driven than after the parts have become thoroughly “worked in.” The car which is driven slowly and carefully when new usually gives the most satisfactory service in the end. Never start out with your car until you are sure that it has plenty of oil and water. Frequently inspect the running gear. See that no unnecessary play exists in either front or rear wheels, and that all bolts and nuts are tight. Make a practice of taking care of every repair or adjustment as soon as its necessity is discovered. This attention requires but little time and may avoid delay or possible accident on the road. We aim to deliver the car in proper mechanical adjustment. Afterwards it is plainly the duty of the driver to keep it in that condition.

II

THE FORD ENGINE

_Q_. What is the principle of the gasoline driven engine?

_A_. Gasoline when mixed with air and compressed is highly explosive. An explosion is a violent expansion caused by instantaneous combustion of confined gases. In the gasoline engine the mixture is drawn into the cylinder, where it is compressed by an advancing piston and then exploded by an electric spark, which sends the piston violently downward, and through the connecting rod imparts a rotary motion to the crank shaft. (See cut No. 147.)

_Q_. What are functions of the pistons?

_A_. On the downward stroke the suction of the piston draws the fresh gas from the carburetor, through the inlet pipe and valve, into the cylinder. The upward movement of the piston compresses the gas into a very small space, between the top of the piston and the depression in the cylinder head, known as the “combustion chamber.” (The compressed gases inert a pressure of approximately 60 pounds to the square inch.) At this point the electric spark, generated by the magneto, explodes the gas-driving piston downward, thus producing the power which turns the crank shaft. On the next stroke upward the piston drives the exploded gas out through the exhaust valve and pipe to the muffler. The accompanying cut shows clearly the relative positions of the pistons and valves during the different strokes.

_Q_. How is the connecting rod removed?

_A_. It is a vanadium steel rod connecting piston and crank shaft. Should the babbitt bearing become worn, or burned out through lack of oil, a knocking in the engine will result, in which case the entire connecting rod should be replaced. To make this replacement, (1) drain oil from crank case; (2) take off cylinder head; (3) remove detachable plate on bottom of crank case; (4) disconnect connecting rod from crank shaft; (5) take piston and rod out through top of cylinder.

Exhaust Valve

Spark Plug

Exhaust and Intake
Pipe Clamp

Cylinder
Head Bolt

Top Water Connection

Intake Valve

Water Chamber

Comp. Chamber

Reverse Pedal

Piston Ring

Cylinder
Head

Fan

Crank Handle

Clutch Pedal

Piston

Exhaust
Manifold

Grease Cup

Brake Pedal

Magneto Contact

Fan Bracket

Transmission Cover

Magneto
Contact Point

Intake Pipe

Fan Bracket Bolt

Bracket Pipe

Triple Gear

Fan Belt

Adjusting Nut

Large Time Gear

Reverse Band

Commutator

Slow Speed Band

Com. Wire Terminal

Brake Band

Starting Pin

Driving Plate

Drive Pulley

Starting Crank

Starting Crank Spring

Cam Shaft
Front Bearing

Starting Crank Sleeve

Starting Crank Ratchet

Clutch Spring

Push Rod

Small Time Gear

Clutch Release Fork

Cam Shaft Rear Bearing

Crank Case Oil Tube

Crank Shaft Front Bearing

Clutch Release Ring

Magneto

Crank Shaft Rear Bearing

Crank Shaft Center Bearing

Valve Spring

Clutch Shift

Magneto Support

Magneto Coil Support

Crank Shaft

Cam Shaft

Clutch Finger

Magneto Clamp

Magneto Coil

Connecting Rod

Oil Level

Flywheel

Oil Cocks

Oil Drain Plug

Fig. 147. Ford Motor--Sectional View]

_Q._ What is the valve arrangement?

_A._ One intake and one exhaust valve are located in each cylinder. The former admits the fresh gas drawn from the carburetor through the inlet pipe, the latter permits the exploded gas to be driven out through the exhaust pipe. The valves are alternately opened and closed (see Fig. 148) by the cams on the cam shaft striking against push rods which in turn lift the valves from their seats.

Intake Stroke
Exhaust Valve Closed
Intake Valve Open

Exhaust Valve Closed
Intake Valve Closed
Explosion Stroke

Compression Stroke
Intake Valve Closed
Exhaust Valve Closed

Intake Valve Closed
Exhaust Valve Open
Exhaust Stroke

Push Rod

Large Time Gear

Comm. Brush Assb.

Zero Marks on Time Gear

Small Time Gear

Crank Shaft

Cam Shaft

Exhaust Cam

Connecting Rod

Intake Cam

Fig. 148. Ford Motor--Valve and Cylinder Assembly]

_Q._ What about valve timing?

_A._ In timing the engine the points of opening and closing of the valves are, of course, what should be considered. As the valves are properly timed at the factory when the engine is built, the necessity for retiming would occur only when such parts as the cam shaft, time gears, or valves were removed in overhauling the engine. In fitting the large time gear to the cam shaft it is important to see that the first cam points in a direction opposite to the zero mark (see Fig. 148). The time gears must also mesh so that the tooth marked (0) on the small time gear will come between the two teeth on the large gear at the zero point. The time gears now being properly set, the exhaust valve on No. 1 cylinder is open and the intake valve closed, the other valves being in the position indicated in cut No. 148. The opening and closing of the valves are as follows: The exhaust valve opens when the piston reaches ⁵⁄₁₆″ of bottom center, the distance from the top of the piston head to the top of the cylinder casting measuring 3³⁄₈″. The exhaust valve will close on top center, the piston being ⁵⁄₁₆″ above the cylinder casting. The intake valve opens ¹⁄₁₆″ after the top center and closes ⁹⁄₁₆″ after bottom center, the distance from the top of the piston to the top of the cylinder casting measuring 3¹⁄₈″ The clearance between the push rod and the valve stem should never be greater than ¹⁄₃₂″ nor less than ¹⁄₆₄″. The correct clearance is naturally halfway between these two measurements. The gap should be measured when the push rod is on the heel of the cam.

_Q._ What about the care of the valves?

_A._ They seldom get out of order, but they do get dirty as a result of carbon collecting on the valve seats. These carbon deposits, by preventing proper closing of the valves, permit the gases under compression to escape, resulting in loss of power and uneven running of the motor. If, when turning the engine over slowly, there is lack of resistance in one or more cylinders, it is probable that the valves need regrinding. As the “life” of the engine depends largely upon the proper seating of the valves, it is necessary that they be ground occasionally.

_Q._ How are valves removed for grinding?

_A._ (1) Draining radiator; (2) remove cylinder head; (3) remove the two valve covers on the right side of the engine; (4) raise the valve spring with lifting tool and pull out the little pin under the valve seat. The valve may then be lifted out by the head, preparatory to grinding.

_Q._ How are valves ground?

_A._ For this work use a good grinding paste of ground glass and oil procurable from auto supply houses. A convenient way is to put a small amount in a suitable dish, adding a spoonful or two of kerosene and a few drops of lubricating oil to make a thin paste. Place the mixture sparingly on the bevel face of the valve. Put the valve in position on the valve seat, and rotate it back and forth (about a quarter turn) a few times with a Ford grinding tool. Then lift slightly from the seat, change the position and continue the rotation, and keep on repeating this operation until the bearing surface is bright and smooth. The valve should not be turned through a complete rotation, as this is apt to cause scratches running around the entire circumference of the valve and seat. When the grinding is completed the valve should be removed from the cylinder, thoroughly washed with kerosene, and the valve seat wiped out thoroughly. Extreme care should be taken that no abrasive substance gets into the cylinders or valve guides. This can be avoided if the grinding paste is applied sparingly on the bevel face of the valve. If the valve seat is worn badly or smeared, it is best to have it reseated with a valve seating tool. This operation requires considerable skill, and perhaps had better be done by an expert mechanic. Care should be exercised against making too deep a cut, necessitating the retiming of the valve.

_Q._ What should be done when the valves and push rods are worn?

_A._ When the valves and push rods become worn so as to leave too much play between them, thus reducing the lift of the valves and diminishing the power of the motor, it is best to replace the push rods with new ones. The clearance between the push rod and the valve stem should never be greater than ¹⁄₃₂″ nor less than ¹⁄₆₄″. If the clearance is greater, the valve will open late and close early, resulting in uneven running of the motor. If the clearance is less than ¹⁄₆₄″ there is danger of the valve remaining partially open all the time. If replacing the push rod does not give the proper clearance, the valve should also be replaced. We do not recommend drawing out the valve stem, as the operation required, and the price of a new part does not warrant the time and expense necessary to properly do the work.

_Q._ What about valve springs?

_A._ When the valves fail to seat themselves properly, there is a possibility that the springs may be weak or broken. A weak inlet spring would probably not affect the running of the engine, but weakness in the exhaust valve spring causes a very uneven action, which is difficult to locate. The symptoms are a lag in the engine due to the exhaust valve not closing instantaneously, and as a result a certain per cent. of the charge under compression escapes, greatly diminishing the force of the 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 by a new one.

_Q._ What causes “knocking” in the engine?

_A._ 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 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.

_Q._ How may the different knocks be distinguished?

_A._ (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 sound is 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 as a dull thud when the car is going up hill. (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 divisions.

_Q._ How is carbon removed from the combustion chamber?

_A._ 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 from the cylinder and piston heads the carbonized matter, being careful to prevent the specks of carbon from getting into the cylinders or bolt holes. In replacing 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.

_Q._ How are spark plugs cleaned?

_A._ After removing the plug from the engine the points may be cleaned with an old tooth brush dipped in gasoline. However, 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 be finally 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 ¹⁄₃₂″, 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.

_Q._ How is the power plant removed from the car?

_A._ (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 uncovering 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 “2 by 4,” or 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.

_Q._ How are the connecting rod bearings adjusted?

_A._ 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 the first connecting rod cap, and drawfile the ends a very little at a time; (4) Replace cap, being careful to see that punch marks correspond, and tighten bolts until it fits shaft snugly; (5) Test tightness of bearing by turning engine over with 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 the work is finished.

Remember that 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 agent or branch house for exchange at a price of 75 cents 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, satisfactory results will not be obtained. The constant tapping of a loose connecting rod on the crank shaft will eventually produce crystallization of the steel, resulting in broken crank shaft and possibly other parts of the engine damaged.

_Q._ How are the crank shaft main bearings adjusted?

_A._ Should the stationary bearings in which the crank shaft revolves become worn (evidenced by a pounding in the motor) and need replacing or adjustment, proceed as follows: (1) After the engine has been taken out of the car, remove crank case, transmission cover, cylinder head, pistons, connecting rods, transmission and magnetic coils. Take off the three babbitted caps and clean the bearing surfaces with gasoline. Apply Persian blue or red lead to the crank shaft bearing surfaces, which will enable you, in fitting the caps, to determine whether a perfect bearing surface is obtained.

(2) Place the rear cap in position and tighten it up as much as possible without stripping the bolt threads. When the bearing has been properly fitted, the crank will permit moving with one hand. If the crank shaft cannot be turned with one hand, the contact between the bearing surface is evidently too close, and the cap requires ohming up, one or two brass lines usually being sufficient. In case the crank shaft moves too easily with one hand, the shims should be removed and the steel surface of the cap filed off, permitting it to set closer.

(3) After removing the cap, observe whether the blue or red “spottings” indicate a full bearing the length of the cap. If “spottings” do not show a true bearing, the babbitt should be scraped and the cap refitted until the proper results are obtained.

(4) Lay the rear cap aside and proceed to adjust the center bearing in the same manner. Repeat the operation with the front bearing, with the other two bearings laid aside.

(5) When the proper adjustment of each bearing has been obtained, clean the babbitt surface carefully and place a little lubricating oil on the bearings, also on the crank shaft; then draw the caps up as closely as possible, the necessary shims, of course, being in place. Do not be afraid of getting the cap bolts too tight, as the shim under the cap and the oil between the bearing surfaces will prevent the metal being drawn into the close contact. If oil is not put on the bearing surfaces, the babbitt is apt to cut out when the motor is started up before the oil in the crank case can get into the bearing. In replacing the crank case and transmission cover on the motor, it is advisable to use a new set of felt gaskets to prevent oil leaks.

III

THE FORD COOLING SYSTEM

_Q._ How is the engine cooled?

_A._ The heat generated by the constant explosions in the engine would soon overheat and ruin the engine were it not cooled by some artificial means. The Ford engine is cooled by the circulation of water in jackets around the cylinders. The heat is extracted from the water by its passage through the thin metal tubing of the radiator, to which are attached scientifically worked out fins, which assist in the rapid radiation of the heat. The fan, just back of the radiator, sucks the air around the tubing through which the air is also driven by the forward movement of the car. The belt should be inspected frequently and tightened by means of the adjusting screw in the fan bracket when necessary. It should not be too tight, however. Take up the slack till the fan starts to bind when turned by hand.

_Q._ How does the water circulate?

_A._ The cooling apparatus of the Ford car is known as the thermo-syphon system. It acts on the principle that hot water seeks a higher level than cold water. Consequently when the water reaches a certain heat, approximately 180 degrees Fahrenheit, circulation commences and the water flows from the lower radiator outlet pipe up through the water jackets, into the upper radiator water tank, and down through the tubes to the lower tank, to repeat the process.

_Q._ What are the causes of overheating?

_A._ (1) Carbonized cylinders; (2) too much driving on low speed; (3) spark retarded too far; (4) poor ignition; (5) not enough or poor grade oil; (6) racing motor; (7) clogged muffler; (8) improper carburetor adjustment; (9) fan not working properly on account of broken or slipping belt; (10) improper circulation of water due to clogged or jammed radiator tubes, leaky connections or low water.

_Q._ What should be done when the radiator overheats?

_A._ Keep the radiator full. Do not get alarmed if it boils occasionally, especially in driving through mud and deep sand or up long hills in extremely warm weather. Remember that the engine develops the greatest efficiency when the water is heated nearly to the boiling point. But if there is persistent overheating when the motor is working under ordinary conditions, find the cause of the trouble and remedy it. The chances are that the difficulty lies in improper driving or carbonized cylinders. Perhaps twisting the fan blades at a greater angle to produce more suction may bring desired results. By reference to the proper division of this book each of the causes which contribute to an overheated radiator is treated and remedies suggested. No trouble can result from the filling of an overheated radiator with cold water, providing the water system is not entirely empty, in which case the motor should be allowed to cool before the cold water is introduced.

_Q._ How about cleaning the radiator?

_A._ The entire circulation system should be flushed out occasionally. To do this properly, the radiator inlet and outlet hose should be disconnected, and the radiator flushed out by allowing the water to enter the filler neck at ordinary pressure, from whence it will flow down through the tubes and out at the drain cock and hose. The water jackets can be flushed out in the same manner. Simply allow the water to enter into the cylinder head connections and to flow through the water jackets and out at the side inlet connection.

_Q._ Will the radiator freeze in winter?

_A._ Yes; unless an anti-freezing solution is used in the circulating system you are bound to experience trouble. As the circulation does not commence until the water becomes heated, it is apt to freeze at low temperature before it commences to circulate. In case any of the radiator tubes happen to be plugged or jammed they are bound to freeze and burst open if the driver undertakes to get along without using a non-freezing solution. Wood or denatured alcohol can be used to good advantage. The following table gives the freezing points of solutions containing different percentages of alcohol: 20% solution freezes at 15 degrees above zero. 30% solution freezes at 8 degrees below zero. 50% solution freezes at 34 degrees below zero. A solution composed of 60% water, 10% glycerine and 30% alcohol is commonly used, its freezing point being about 8 degrees below zero. On account of evaporation fresh alcohol must be added frequently in order to maintain the proper solution.

_Q._ How are leaks and jams in the radiator repaired?

_A._ A small leak may be temporarily repaired by applying brown soap or white lead, but the repair should be made permanent with solder as soon as possible. A jammed radiator tube is a more serious affair. While the stopping of one tube does not seriously interfere with the circulation, it is bound to cause trouble sooner or later, and the tube will freeze in cold weather. Cut the tube an inch above and below the jam and insert a new piece, soldering the connections. If the entire radiator is badly jammed or broken it would probably be advisable to install a new one.

IV

THE GASOLINE SYSTEM

_Q._ How does the carburetor work?

_A._ The carburetor is of the automatic float feed type, having but one adjustment, the gasoline needle valve. The cross-section diagram of carburetor (Fig. 149) shows how the gasoline enters the carburetor, is vaporized by a current of air and passes through the inlet pipe to the engine in the form of an explosive mixture. The gasoline, entering the bowl of the carburetor, gradually raises the float to a point where the inlet needle is forced upwards into its seat, thus cutting off the flow of gasoline. As the gasoline in the bowl recedes, the float lowers, allowing the needle to drop from its seat and the flow of gasoline is resumed. It is plain to see that a constant level of gasoline is maintained in the carburetor by the automatic action of float and needle. The quantity of gasoline entering into the mixture is governed by the needle valve (_see_ following page). The volume of gas mixture entering the inlet pipe is controlled by opening and closing the throttle, according to the speed desired by the driver.

Gasoline Tank

Inlet Pipe

Needle Valve

Needle Valve
Lock Screw

Air Gate Lever

Throttle Lever

Clamp Screw

Screen
(Gasoline Strainer)

Air Current

Throttle
Stop Screw

Air Intake Gate

Throttle Gate

Stop Cock

Cork Float

Gasoline Inlet Needle

Sediment Bulb

Feed Pipe

Carburetor
Drain Cock

Sediment Bulb
Drain Cock

Fig. 149. Ford Fuel System]

_Q._ Why is carburetor adjustment placed on dash?

_A._ For the convenience of the driver in adjusting the carburetor. After the new car has become thoroughly worked in, the driver should observe the angle of the carburetor adjustment rod at which the engine runs most satisfactorily. In cold weather it will probably be found necessary to turn the dash adjustment one-quarter turn to the left, particularly in starting a cold engine. As gasoline vaporizes readily in warm weather, the driver will find it economical to reduce the quantity of gasoline in the mixture by turning the carburetor adjustment to the right as far as possible without reducing the speed. This is particularly true when taking long drives where conditions permit a fair rate of speed to be maintained, and accounts for the excellent gasoline mileage obtained by good drivers.

_Q._ What is meant by a “lean” and a “rich” mixture?

_A._ A lean mixture has too much air and not enough gasoline. A rich mixture has too much gasoline and not enough air. A rich mixture will not only quickly cover the cylinders, pistons and valves with soot, but will tend to overheat the cylinders, and is likewise wasteful of the fuel. It will often choke the engine and cause misfiring at slow speeds, although at high speeds the engine will run perfectly. The mixture should be kept as lean as possible without the sacrifice of any of the power of the motor. A lean mixture will often result in backfiring through the carburetor, for the reason that the gas burns slowly in the cylinder, and is still burning when the inlet valve opens again, which causes the gas in the intake to ignite. A rich mixture is shown by heavy, black exhaust smoke with a disagreeable smell. Proper mixture will cause very little smoke or odor.

_Q._ How is the carburetor adjusted?

_A._ The usual method of regulating the carburetor is to start the motor, advancing the throttle lever to about the sixth notch, with the spark retarded to about the fourth notch. The flow of gasoline should now be cut off by screwing the needle valve down to the right until the engine begins to misfire. Then gradually increase the gasoline feed by opening the needle valve until the motor picks up and reaches its highest speed and no trace of black smoke comes from the exhaust. Whenever it is necessary to turn the adjusting needle down more than a quarter turn below its normal position, the lock nut on the top of the carburetor at the point through which the needle passes should first be loosened, as otherwise it is impossible to tell when the needle is turned down in its seat too far. Turning the needle down too tightly will result in its becoming grooved and the seat enlarged. When those parts are damaged it is difficult to maintain proper adjustment of the carburetor. Having determined the point where the motor runs at its maximum speed, the needle valve lock nut should be tightened to prevent the adjustment being disturbed. For average running a lean mixture will give better results than a rich one.

_Q._ Why does water clog the carburetor?

_A._ The presence of water in the carburetor or gasoline tank, even in small amounts, will prevent easy starting and the motor will misfire and stop. As water is heavier than gasoline it settles to the bottom of the tank and into the sediment bulb along with other foreign matters. As it is difficult nowadays to get gasoline absolutely free from impurities, especially water, it is advisable to frequently drain the sediment bulb under the gasoline tank. During cold weather the water which accumulates in the sediment bulb is likely to freeze and prevent the flow of gas through the pipe leading to the carburetor. Should anything of this kind happen it is possible to open the gasoline line by wrapping a cloth around the sediment bulb and keeping it saturated with hot water for a short time. Then the water should be drained off. In event of the water getting down into the carburetor and freezing, the same treatment may be applied.

_Q._ What makes the carburetor leak?

_A._ The flow of gasoline entering the carburetor through the feed pipe is automatically regulated by the float needle raising and lowering in its seat. Should any particle of dirt become lodged in the seat, which prevents the needle from closing, the gasoline will overflow in the bowl of the carburetor and leak out upon the ground.

_Q._ What should be done when there is dirt in the carburetor?

_A._ The spraying nozzle of the carburetor having a very small opening, a minute particle of dirt or other foreign matter will clog up the orifice. The result is that the motor will begin to misfire and slow down as soon as it has attained any considerable speed. This is accounted for by the fact that at high speeds the increased suction will draw the particles of dust, etc., into the nozzle. By opening the valve needle half a turn and giving the throttle lever two or three quick pulls the dirt or sediment will often be drawn through, when the needle may be turned back to its original place. If this does not accomplish the purpose, the carburetor should be drained.

_Q._ If the engine runs too fast or chokes with throttle retarded, what is to be done?

_A._ If the engine runs too fast with throttle fully retarded, unscrew the carburetor throttle lever adjusting screw until the engine idles at suitable speed. If the motor chokes or stops when throttle is fully retarded, the adjusting screw should be screwed until it strikes the boss, preventing the throttle from closing too far. When proper adjustment has been made, tighten lock screw so that adjustment will not be disturbed.

_Q._ What is the purpose of the hot air pipe?

_A._ It takes the hot air from around the exhaust pipe and conducts it to the carburetor where the heat facilitates the vaporizing of the gasoline. It is usually advisable to remove this pipe in the hot season, but it is an absolutely necessary feature during cold weather.

_Q._ What is the purpose of the cork float?

_A._ It automatically controls the flow of gasoline into the carburetor. If it floats too low, starting will be difficult; if too high, the carburetor will flood and leak. A cork float which has become fuel soaked should be removed and replaced by a new one or thoroughly dried and then given a couple of coats of shellac varnish to make it waterproof.

_Q._ Should priming rod be used in cranking when motor is warm?

_A._ No. The carburetor does not ordinarily require priming when the motor is warm, and cranking with the rod pulled out is apt to “flood” the engine with an over rich mixture of gas, which does not readily explode. This naturally causes difficulty in starting. If you should accidentally flood the engine, turn the carburetor adjusting needle down (to the right) until it seats; then turn the engine over a few times with the starting crank in order to exhaust the rich gas. As soon as the motor starts, turn back the needle to the left and readjust the carburetor.

V

THE FORD IGNITION SYSTEM

_Q._ What is the purpose of the ignition system?

_A._ It furnishes the electric spark which explodes the charge in the combustion chamber, thus producing the power which runs the engine. It is important that the charge be correctly ignited at the proper time, in order to obtain satisfactory results in running the car. In the Ford car the ignition system is as simple as it is possible for human invention to make it.

_Q._ How does the magneto generate the current?

_A._ In revolving at the same rate of speed as the motor, the magnets on the flywheel passing the stationary coil spools create an alternating low tension electric current in coils of wire which are wound around spools fastened to the stationary part of the magneto, and is carried from these coils to the magneto connection (wire) leading to the coil box on the dash.

_Q._ Should the coil vibrator adjustment be disturbed?

_A._ The present style of coil unit is properly adjusted when it leaves the factory and this adjustment should not be disturbed unless to install new points or to reduce the gap between the points which may have increased from wear. When adjustments are necessary they should, whenever possible, be made by one of the Ford service stations who have special equipment for testing and adjusting units and will gladly furnish expert service. If the points are pitted they should be filed flat with a fine double-faced file and the adjusting thumb nut turned down so that with the spring held down the gap between the points will be a trifle less than ¹⁄₃₂ of an inch. Then set the lock nut so that the adjustment cannot be disturbed. Do not bend or hammer on the vibrators, as this would affect the operation of the cushion spring of the vibrator bridge and reduce the efficiency of the unit.

_Q._ How is a weak unit detected?

_A._ With the vibrators properly adjusted, if any particular cylinder fails or seems to develop only a weak action, change the position of the unit to determine if the fault is actually in the unit. The first symptom of a defective unit is the buzzing of the vibrator with no spark at the plug. Remember that a loose wire connection, faulty spark plug, or worn commutator may cause irregularity in the running of the motor. These are points to be considered before laying the blame on the coil.

_Q._ How may short circuit in commutator wiring be detected?

_A._ Should the insulation of the primary wires (running from coil to commutator) become worn to such an extent that the copper wire is exposed, the current will leak out (i. e., short circuit) whenever contact with the engine pan or other metal parts is made. A steady buzzing of one of the coil units will indicate a “short” in the wiring. When driving the car the engine will suddenly lag and pound on account of the premature explosion. Be careful not to crank the engine downward against compression when the car is in this condition, as the “short” is apt to cause a vigorous kick back.

_Q._ Does coil adjustment affect starting?

_A._ Yes. When the vibrators are not properly adjusted more current is required to make and break the contact between the points, and, as a result, at cranking speeds you would not get a spark between the spark plug points. Do not allow the contact points to become “ragged,” otherwise they are apt to stick and cause unnecessary difficulty in starting, and when running they are apt to produce an occasional “miss” in the engine.

_Q._ What is the purpose of the commutator?

_A._ The commutator (or timer) determines the instant at which the spark plugs must fire. It affects the “make and break” in the primary circuit. The grounded wire in the magneto allows the current to flow through the metal parts to the metal roller in the commutator. Therefore, when the commutator roller in revolving, touches the four commutator contact points, to each of which is attached a wire connected with the coil unit, an electrical circuit is passed through the entire system of primary wires. This circuit is only momentary, however, as the roller passes over the contact point very rapidly and sets up the circuit in each unit as the roller touches the contact point connected with that unit. The commutator should be kept clean and well oiled at all times.

_Q._ What about the spark plug?