The automobile owner's guide

by Frank B. Scholl

INSTRUCTIONS FOR INSTALLING AND ADJUSTING THE SCHEBLER FORD “A” CARBURETOR

First, remove the Ford carburetor from the manifold, also the dash board control, the hot air drum, and tubing, and the radiator choke wire. Be sure to save the cotter pin used in the throttle control.

Install the Schebler carburetor, using gasket and cap screws which are furnished with the equipment. The gasoline connection is the same as regularly furnished on the Ford equipment and no other connections are necessary. Screw the connections on the Ford gasoline line onto the connection furnished on the carburetor. Attach the hot air drum and the tubing to the exhaust manifold and run the choke wire through the radiator.

Before adjusting carburetor, see that the spark plugs are clean and set about .035, or nearly the thickness of a new dime. See that the compression is good and equal on all four cylinders. See that the timer is clean and in good shape, as an occasional miss is due to the roller in the timer becoming worn. Also, be sure that there is no leak in the intake manifold.

The steering post control must be set so that the tubing is fastened into set screw (A) and the control wire is fastened through the binding post in lever (B) with steering post control or plunger pushed clear in and the butterfly shutter (D) in the hot air horn or bend open, so that when the plunger control is pulled out the wire (C) in the binding post (B) on lever closes the shutter (D) almost completely. This will furnish a rich mixture for starting and warming up the motor under normal weather conditions.

The wire running to the front of the radiator must be attached to lever (E) so that when the motor is cold, the shutter (D) can be closed tight, thus insuring positive starting. However, this wire must be released immediately upon starting the motor or the motor will be choked by excess of gasoline.

To start the motor, open low speed needle (H) and high speed needle (I) about four or five complete turns. You will note that the needles have dials which indicate turning needle to the right cuts down the gasoline supply.

Pull out steering post control, open throttle about one-quarter way, retard the spark, pull out radiator choke wire which will close shutter and crank the motor. After motor is started, immediately release radiator choke wire and gradually push in the steering post control or plunger and let the motor run until it is warmed up. Then first adjust the high speed needle (I) until the motor runs smoothly and evenly with retarded spark. Close throttle part way and adjust idle needle until motor runs smoothly at low speed.

In order to get the desired low throttle running, use the throttle stop screw (L) which will control the throttle opening and give you the desired low speed running.

A strainer is furnished on the carburetor which prevents dirt or sediment getting into the bowl of the carburetor and choking up the gasoline nozzle or causing flooding.

CHAPTER IX
KEROSENE CARBURETORS

Experiments have been carried on for quite some time pertaining to the development of a more successful carburetor which will burn the heavier fuels. The chief difficulty encountered is to find a more suitable way to vaporize these low grade fuels.

Kerosene can be used, only with an application of heat to the manifold to aid in the evaporation of the heavier parts of this fuel. The exhaust pipes are available for this source of heat, but as there is no heat from this source until the engine is running, it is necessary to start the engine on gasoline and switch over to the heavier fuels after the warming-up process.

Fig. 43. Holley Kerosene Carburetor

[Fig. 43] shows the Holley kerosene carburetor which is adaptable to any type of engine by making simple changes in the exhaust manifold to include the heating coil tube. This carburetor will operate successfully on any hydro-carbon fuel with a boiling point below 600° F. Two float chambers are provided to take care of the starting and running fuels. The engine is started on the gasoline part of the carburetor and after a short warming-up period the feed is switched to the kerosene part of the device.

Fig. 44. Holley Kerosene Carburetor Installment

The principle upon which this device operates is to provide a primary mixture by means of a needle valve and a very small aspirating jet which gives a mixture that is too rich for combustion. This rich mixture of atomized fuel is carried through a coil tube of very thin wall thickness, which is exposed to the exhaust gases, directly in the exhaust manifold.

The temperature in this coil tube reaches as high as 500 degrees F. The globules of the over rich mixture are broken up here and flow directly into the mixing chamber, where additional air enters, diluting the mixture to make it combustible. The opening of the air valve is controlled by the suction of the engine and by the throttle valve. The shifter valve for changing the operation from gasoline to kerosene is conveniently arranged for dash control, when the engine becomes warm. A primer is arranged in the manifold just above the carburetor and aids in cold weather starting.

[Fig. 44] shows the installation of the Holley kerosene carburetor. In this case it was necessary to add a compartment on the exhaust manifold to contain and heat the coil tube. There are some details that must be taken care of on installation. A small auxiliary tank must be provided to hold the gasoline for starting, while a larger tank must be provided to carry the main supply of kerosene.

The adjustments of this type of carburetor is through a needle valve located in each fuel chamber, and as it is impossible to give any set adjustment that would apply to the many different types of motors, the proper adjustment must be worked out. This is done by shifting to the gasoline and turning the needle valve to the right and left and noting the point at which the engine runs the smoothest. The needle valve is then set at this point. The fuel shifter valve is turned to feed the kerosene, and this adjustment is made in the same manner.

CHAPTER X
HEATED MANIFOLDS AND HOT SPOTS

Heat added to the manifold is the probable solution of the present low-test fuel supplied to the motorist. In the first place you may be satisfied if your motor runs and does not give any noticeable loss of power. But the question is, are you getting full power out of your motor in accordance with the amount of fuel consumed? And are you getting the proper amount of mileage out of each gallon? The answer to both questions would probably be in the negative, if both questions were taken up individually by owners.

			EXHAUST	INTAKE
		EXHAUST
	GOVERNOR
			GOVERNOR
CARBURETOR

Fig. 45. Hot Spot Manifold

One of the best solutions, if not the best, is the new hot-spot manifold used on the Liberty engine, which was designed for Army use. [Fig. 45] shows the hot-spot Liberty engine manifold. The intake manifold is external but short, therefore does not offer much opportunity for the liquid to condense. From the carburetor it rises up straight to a point well above the valve ports and the cylinder blocks, and at the top of the rise it touches the exhaust pipe and divides, the two branches sweeping downward quite clear of the exhaust manifold to each block of cylinders. About three inches of the intake passage is exposed to the exhaust manifold top.

The advantage of this design is that the heating element affects practically only the liquid fuel and does not have much effect on the fuel already vaporized. Naturally the liquid fuel is heavier than the vapor, and as the mixture rushes up the manifold at a high rate of speed and turns to the right or left, the heavier liquid particles are thrown straight against the hot-spot, where they are boiled off in vapor.

Thus, although the total amount of heat supplied to the incoming charge is small, vaporization is good, since pains have been taken to supply the heat where it is needed.

Fig. 46. Holley Vapor Manifold—Ford Cars

[Fig. 46] shows the Holley vapor manifold for Ford cars which is intended to completely vaporize gasoline by applying heat at the proper point. As will be noted by the arrows, the exhaust gases pass down, striking a hot-spot at the top of the internal intake passage. The exhaust gases flow along this passage and finally pass out at the bottom. The heavier particles of fuel, after leaving the carburetor, strike against the wall at point (A) and there are broken up by the exhaust gases. Should any of the globules not be broken up at this point, they will be vaporized when they strike the hot-spot at (B) as this is directly in contact with the exhaust gases. It will be noted that the heavier globules are subjected to a rising temperature. Starting at (A) and finishing at (B) a control valve regulates the amount of heat supplied to the intake manifold.

CHAPTER XI
COOLING SYSTEMS
Type, Operation and Care

Cooling systems are provided on all types of gasoline engines. As the heat generated by the constant explosions in the cylinders would soon overheat and ruin the engine were it not cooled by some artificial means.

Circulation Systems.—There are two types of water circulating systems. The Thermo Syphon, and the Force Pump circulating systems.

Fig. 47. Thermo-Syphon Cooling System

[Fig. 47] shows how the water circulates in 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 temperature, approximately 180° F., circulation commences and the water flows from the lowest radiator outlet pipe up through the water jackets into the upper radiator water tank, and down through the thin tubes to the lower tank to repeat the process.

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 through the small tubes which connect the upper and lower radiator tanks. The air is also driven through between these tubes by the forward movement of the car.

The Force Pump Circulation System.—The Force Pump circulating system is constructed in the same manner as the Thermo Syphon Cooling System. The only difference in the two systems is that a small pump is attached to the lower radiator pipe to force the circulation of the water.

The pump is usually of the centrifugal type and consists of a fan-shaped wheel operated in a snugly fitted housing. The water enters at the hub and is thrown out against the housing and is forced on by the rapid action of the fan blades. Another type of pump is used by some manufacturers which consist of two meshed gears of the same size, which operate in a snugly fitted housing. These gears operate in a direction toward each other, the water is carried forward or upward in the space between the teeth, and is forced on when the teeth mesh and fill the space.

Overheating.—Overheating may be caused by carbonized cylinders, too much driving on low speed, not enough or a poor grade of lubricating oil, spark retarded too far, racing the engine, clogged muffler, poor carburetor adjustment, a broken or slipping fan belt, jammed radiator tube, leaky connection, or low water.

Radiator Cleaning.—The entire circulation system should be thoroughly cleaned occasionally. A good cleaning solution is made by dissolving one-half pound of baking soda in three and one-half to four gallons of soft water. The radiator is filled with the solution and left to stand for twenty to thirty minutes. The hose is then removed from the lower pipe, water is then turned into the radiator through the filler spout until the system is thoroughly flushed out.

Freezing.—Unless an anti-freezing solution is used through the cold months you are bound to experience trouble. The circulation does not commence properly until the water becomes heated. It is apt to freeze at low temperatures before circulation commences. In case any of the small tubes are plugged or jammed they are bound to freeze and burst open if the driver attempts to get along without a non-freezing solution.

Freezing Solution.—Wood or denatured alcohol can be used to a good advantage. The following table gives the freezing point of solutions containing different percentages of alcohol.

20% solution freezes at 15° above zero.
30% solution freezes at  8° below zero.
50% solution freezes at 34° below zero.

A solution composed of 60% of water, 10% of glycerine, and 30% of alcohol is commonly used, its freezing point being 8° below zero.

Evaporation.—On account of evaporation, fresh alcohol must be added frequently in order to maintain the proper solution.

Radiator Repairs.—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 up of one tube does not seriously interfere with 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 connection. If the entire radiator is badly jammed or broken, it will probably be advisable to install a new one.

Air Cooling System.—Air cooling has been developed to a point where fairly good results are attained. This system has an advantage over the circulating systems, in that the weight of the radiator and water is done away with, and no trouble is experienced with stoppage of circulation and leaky connection. This system, however, has its drawbacks, in that it cannot be used successfully on the larger and more compact engines. In order to allow the necessary large space for radiation, the cylinders are heavily flanged and set separately. The fan is placed in a much higher position than usual, in order that the air current may strike the heads of the cylinders and circulate downward. Compression is also lowered considerably to prevent heat generation and pre-ignition. On account of the small size of the cylinders and low compression, it is necessary to operate an air cooled engine at a very high rate of speed to produce sufficient power for automobile locomotion.

The fan must be kept in good working condition, and care should be exercised in not allowing the engine to run idle for any length of time.

CHAPTER XII
MUFFLER CONSTRUCTION, OPERATION AND CARE

The muffler was designed to silence the otherwise loud report of the exploding charge of gas, which is released from the cylinders by the sudden opening of the exhaust valves.

While these devices are differently shaped and formed, the functional purpose and action is practically the same in all designs.

The burnt or inert gases are forced from the cylinders on the exhaust stroke. It passes into the exhaust manifold which absorbs some of the heat before it reaches the muffler.

Hanger	Tie Rod
Split Clamp Nut	Muffler Shell	Spacer Spacer	Nozzle
		Center Pipe

Fig. 48. Muffler—Three Compartment

[Fig. 48] shows a three compartment muffler. The burnt gases enter compartment No. 1 from the exhaust pipe. This compartment is sufficiently large to spread the volume which lessens the pressure and force. It then enters the rear compartment No. 3, through the center pipe; it expands again and passes through the perforated spacer plate, enters compartment No. 2, and escapes through the nozzle in an even silent flow.

The muffler at all times produces a certain amount of back-pressure on the engine which results in a slight loss of power. The back pressure exerted by the majority of mufflers, however, is very slight and has a tendency to counter balance or equalize the sudden shock delivered to the bearings by the explosion over the piston head.

The muffler may also become fouled by the use of too much or too heavy a grade of lubricating oil, which will cause the expansion space and the small holes in the spacer plates to become clogged with carbon and soot. This carbon and soot soon bakes into a hard crust causing much back pressure which results in a considerable loss of power. This condition will become noticeable first by a loss of considerable power caused by an overheated motor. If this condition is not remedied, the exhaust manifold and pipe leading to the muffler will soon become red-hot, causing much danger of a serious damage loss to the car from fire.

Fig. 49. Muffler

Muffler.—To eliminate or remedy this condition, disconnect manifold pipe from the muffler, remove the muffler from hangers, and disassemble it by removing the nuts from the tie rods which release the end plates. This will allow the compartment walls and spacer plates to be drawn from the sleeve. Each compartment and spacer plate should be removed sectionally, and its position carefully noted, in order that it may be replaced correctly in re-assembling. The walls of the sleeve, and the compartment end plates are scraped and rubbed with a piece of sandpaper. A small round file may be used in cleaning the center pipe. The spacer plates are scraped and sandpapered. The small holes in the spacer plates may be opened by using the tapered end of a small file. [Fig. 49] shows a muffler of another design. The burnt gas enters a compartment containing three saucer shaped spacers which retard and break up the volume. It then passes through an open compartment and enters reversed spacers through small holes near the sleeve wall. It centers or forms slightly in volume and escapes to the next compartment through a small hole in the center of the second spacer. This action of forming and breaking is kept up until the outlet is reached.

CHAPTER XIII
VACUUM SYSTEMS
Construction, Operation and Care

The vacuum systems have proved to be one of the important inventions pertaining to successful motor operation. They are self contained, simple in construction and automatic in operation. They do away with the troublesome power and hand pressure pumps and their connections.

		AIR VENT
			FROM INTAKE MANIFOLD
FROM GASOLINE SUPPLY TANK

Fig. 50. Vacuum System—Top Arrangement

[Fig. 50] shows the top arrangement and connections. R is the air vent over the atmospheric valve. The effect of this is the same as if the whole tank were elevated, and is for the purpose of preventing an overflow of gasoline, should the position of the car ever be such as to raise the fuel supply tank higher than the vacuum tank. D shows the pipe connection from the fuel supply tank. C shows the pipe connection to the intake manifold. W shows a tap or vent through which gasoline may be fed into the upper chamber, in case the fuel supply tank is damaged or put out of commission. R shows the air vent connection from the lower tank.

[Fig. 51] shows a general diagram of vacuum system installation. One of the chief advantages is that it allows the carburetor to be placed near the head of the motor and does away with the long manifold connections required with the gravity feed systems. This also reduces the frictional resistance, gives a richer mixture and greater volume of flow.

		AIRVENT
A—CONNECTION BETWEEN INTAKE MANIFOLD AND VACUUM TANK
	C—CONNECTION FROM VACUUM TANK TO CARBURETOR	B— CONNECTION BETWEEN MAIN GASOLINE SUPPLY TANK AND VACUUM TANK

Fig. 51. Vacuum System Installation

[Fig. 52] shows a sectional view of the Stewart Vacuum System and explains the operative value of each part. A is the suction valve for opening and closing the connection to the manifold through which a vacuum is extended from the engine manifold to the gasoline tank. B is the atmospheric valve, and permits or prevents an atmospheric condition in the upper chamber. When the suction valve A is open and the suction is drawing gasoline from the main supply tank, the atmospheric valve B is closed. When the suction valve A is closed, the atmospheric valve B must be open, as an atmospheric condition is necessary in the upper tank in order to allow the gasoline to flow through the flapper valve H into the lower chamber. C is a pipe connecting the tank to the intake manifold of the engine. D is a pipe connecting the tank to the main fuel supply tank. E is the valve control lever and has two coil tension springs S attached to operate the short valve lever F. G is the metallic air-containing float, which controls the action of the valves through the spring and lever arrangement. H is the flapper valve at the outlet of T, and it closes by suction when the vacuum valve A is open. When the vacuum valve A closes, the atmospheric valve B opens and relieves the suction in the upper tank, the flapper valve H opens and allows the fuel to flow from the upper tank into the lower chamber.

	AIR VENT
			TO INTAKE PASSAGE
FROM GASOLINE TANK
	FLOAT VALVE
UPPER CHAMBER
LOWER CHAMBER
			TO CARBURETOR

Fig. 52. Vacuum System Diagram—Stewart Warner

J is a plug in the bottom of the tank which can be removed to clean or drain the tank. This plug can be removed and replaced with a pet-cock for drawing off gasoline for priming or cleaning purposes. K is the line to the carburetor. It is extended on the inside of the tank to form a pocket for trapping water and sediment. L is a channel space between the inner and outer shells and connects with the air vent R, thus admitting an atmospheric condition to exist in the lower chamber at all times, and thereby permitting an uninterrupted flow of gasoline to the carburetor. R is an air vent over the atmospheric valve; the effect of this valve is the same as if the whole tank was elevated. It is also for the purpose of preventing an overflow of gasoline should the position of the car ever be such as would raise the fuel supply tank higher than the vacuum tank. Through this tube the lower or reservoir chamber is continually open to atmospheric pressure. T is the outlet at the bottom of the float chamber in which the flapper valve H is located. U is the float stem guide. V is a strainer which prevents foreign matter from passing into the vacuum chamber. W is a tap or vent through which gasoline may be fed into the upper chamber if the fuel tank is damaged or put out of commission.

The simple and durable construction of this system makes it unlikely that the car owner will ever need to make internal repairs. Before attempting to repair this tank make sure that the trouble is not due to some other cause.

Air Vent.—A small amount of gasoline may escape through the air vent occasionally. This will do no harm and no adjustment is needed. However, if the vent tube continues to overflow, one of the following conditions will be responsible: 1. The air hole in the main supply tank is stopped up, or the hole is too small. Enlarge the hole or clean it out. 2. If gasoline leaks from the system except from the vent tube, it can only do so from one of the following causes: a. A leak may exist in the outer wall of the tank. If so soldering it up will eliminate the trouble. b. The carburetor connection on the bottom of the tank may be loose. c. There may be a leak in the tubing at the head of the tank. d. The cover of the tank may be loose.

Failure to Feed Gasoline to the Carburetor.—This condition may be due to other causes than the vacuum system. Do not tinker with it until you are sure that the trouble is not elsewhere. Flood the carburetor. If gasoline runs out of the float chamber you may be sure that the vacuum system is performing its work properly.

To Remove Cover.—To remove the cover for inspection, take out the screws and run a knife blade carefully around the top to separate the gasket without damaging it. Shellac the gasket before you replace it to make the tank air-tight.

Faulty Feed.—If faulty feed is traced to the vacuum tank, one of the following conditions may be the cause. The float valve G may have developed a leak. To repair, remove the top of the tank to which it is attached. Dip the float into a pan of hot water. Bubbles will show the leak. Punch two small holes, one at the top, and one at the bottom, and blow the gasoline out. Then solder up the holes and the leak. Use solder carefully in order not to add too much weight to the float. A small particle of dirt may be lodged under the flapper valve. This trouble can usually be remedied by tapping the side of the tank. In order to determine whether or not the flapper valve is working properly, plug up the air vent tube and remove the pipe extending from the bottom of the tank to the carburetor. Start the engine and place a finger over the opening (from which you removed the tube). If continual suction is felt, it is evident that the flapper valve is being held off its seat. If tapping the side of the tank will not remedy this condition, remove the cover and withdraw the upper chamber. The valve is attached to the pipe projecting from the bottom.

Strainer.—Remove and clean the strainer screen located at V, [Fig. 52], every five or six weeks. This screen collects all the dirt and foreign matter in the gasoline, and often becomes stopped up.

CONNECTION TO GASOLINE TANK	SUCTION TUBE CONNECTION TO INTAKE MANIFOLD
STRAINER	VENT TUBE CONNECTION
COVER
	ATMOSPHERIC VALVE
	SUCTION VALVE
VALVE LEVER
	INNER TANK
SPRINGS
	OUTER TANK
FLOAT LEVER
FLOAT
GUIDE
FLAPPER VALVE
DRAIN PLUG	CONNECTION TO CARBURETOR

Fig. 53. Vacuum System—Inside View of Parts—Stewart Warner

Filling the Vacuum Tank.—To fill the tank after it has been cleaned or repaired, leave the spark off, close the gas throttle, and crank the engine over a few times with the starter or by hand. It takes less than ten seconds to create sufficient vacuum to fill the tank.

CHAPTER XIV
ELECTRICAL DICTIONARY OF PARTS, UNITS AND TERMS

Before taking up the study of automobile ignition systems and electrical appliances, we will first devote a little time to study, in order to become familiar with the different electrical parts, functions, terms and names applied to the various units, and machines.

In the first place electricity is not a juice or fluid that flows through a wire, but is a generated electro-motive force that may be held in storage or conducted from one place to another. It will not flow without a round circuit and seeks ground return at the slightest opportunity. It is designated in terms which express quality, quantity, force and action.

Voltage.—A volt is an electrical unit, expressing the force or pressure of the current. The voltage of a system simply means the difference of pressure exerted on the system measured in volts.

Ampere.—An ampere is an electrical unit expressing the quality or intensity of the current.

Ohm.—An ohm is an electrical unit expressing resistance; or the resistance of conductors to the flow of current.

Current.—The current is the generated electro-motive force.

Circuit.—Electricity will not flow unless there is a circuit or ground return to its original source.

Low Tension Current.—Low tension current is generated in the primary winding or coil by placing it in a magnetic field. It will flow from one point to another but has very little strength and will not jump the gap at the spark plug. It is used for lighting purposes, or conducted to an induction coil which transforms it into a high tension alternating current.

High Tension Current.—High tension current is generated in the secondary coil by interruption of the primary current or by the rapid magnetization and demagnetization of the core and primary coil.

Direct Current.—Direct current is produced by placing a coil or wire in a magnetic field. It is usually conducted to an induction coil where it is transformed into a high tension alternating current.

Alternating Currents.—Alternating currents are produced by the rapid breaking down and building up of the primary current. An alternating current flows forward from zero to its highest point of strength and back again to zero. The alternating action takes place so rapidly that a light can be connected in this circuit and it will burn steadily without any noticeable fluctuation.

Fig. 54. Coil Diagram

Induction Coil.—An induction coil consists of a soft iron core; a primary and secondary winding, and a set of platinum points. The primary winding is wound directly over the core and consists of a few turns of thick wire. The secondary wire is wound over the primary and consists of a great many turns of thin wire. [Fig. 54] shows the functional action of an induction coil. Both of the coils are wound on the soft iron core A-B. The primary current which is supplied in this case by a cell or number of cells, C and D, is broken at frequent intervals of time. The method of doing this is as follows: One terminal of the primary coil is connected to the fixed platinum stud D, the other terminal to a spring which carries a piece of soft iron, E. When the spring is unbent it touches the stud D, and a current passes in the primary. The core of soft iron becomes magnetized and attracts the soft iron disc, E, thus breaking contact at D. The current is stopped and the core immediately becomes unmagnetized, the spring flies back and the contact is again made. The process is then repeated. When the contact in the primary is broken the current flows in one direction in the secondary coil, when it is made the current flows in the opposite direction in the secondary. Thus an alternating current is set up in the secondary current of great frequency.

Commutator.—The commutator or timer as it is commonly called is used only in connection with the induction coil to complete the circuit when a spark is required at the plug in the cylinder.

Insulation.—Insulating is the act of covering a conductor with a non-conducting substance to prevent the spark from jumping or seeking ground.

Choking Coil.—A choking coil in simple form consists of a coil and iron core to increase self-induction. It is used to reduce currents of high pressure and is commonly called a bucking coil.

Fuse.—A fuse is used to prevent conductors or coils from being damaged by heat generated from high pressure currents. It consists of a metal and glass tube which contains a fine wire. This wire being much thinner than the wire of the cable, the heat naturally develops faster at this point, and is soon high enough to melt the wire and break or open the circuit, and thus any further damage to the insulation is prevented.

Condenser.—A condenser usually consists of a few strips of folded tin foil insulated from each other with paraffined or oiled paper. It absorbs, restricts and distributes high pressure currents and also prevents excessive sparking at the contact points.

Fig. 55. Dynamo—Diagram of Action

Dynamo.—A dynamo is a machine which converts mechanical energy into electric energy, and must consist of at least two separate parts; the field magnets to create the magnetic field, and the armature or conductor in which the current is generated. One or the other of these must be in motion in order to cut the lines of magnetic force crossing the field. [Fig. 55] shows the operation of the most common or simplest type of alternating current producing machine, which is similar and conforms in action to the high tension magneto and generator. Field pieces magnetize the pole pieces N and S. A wire coil is placed in the field at right angles to the magnetic lines of force turned to the right. It takes up the position of the dotted lines and no lines of force are cut, whereas in its original position, as many lines of force as possible are cut. Turning the coil on its axles, a-b, causes the lines of force cut by c-d, and e-f to vary from the highest number of lines that it is possible to cut to zero and back again, thus constantly changing the flowing direction of the current. The reversal of the current takes place at the instant that the coil passes the point where it cuts the greatest number of lines of force. The ends of the coil are connected to a commutator on the shaft a, b. Steel insulated brushes pick the current from the commutator ring and conduct it to the brush post; an insulated wire conductor is attached to this post and conducts the current to the place of use or storage.

Voltaic Cell.—The source of energy of a voltaic cell is the chemical action. (See [accumulator]).

Accumulator.—The standard accumulator or storage battery is composed of three cells or hard rubber jars in which a number of lead plates are immersed in a solution of sulphuric acid and water known as electrolyte. The plates are stiff lead grids which hold a paste made of various oxides of lead. Six plates in each cell are joined to the positive terminal, and seven plates in each cell are joined to the negative terminal. Thin wooden separators are inserted between the plates to prevent them from touching one another. In the forming process the material on the positive plates becomes converted into brown peroxide of lead; the negative plates assume the form of gray metallic lead. The material on both plates is known as active material. When current is taken from the cells the sulphuric acid in the electrolyte combines with the active material of the plates to form sulphate of lead, and when the battery is recharged the lead sulphate is again converted into the original active material and the acid set free in the solution.

Storage Battery.—For construction and action see [Accumulator]. For care see chapter on [storage batteries].

Electrolyte.—A chemical solution used in voltaic cells consisting of two parts sulphuric acid added to five to seven parts of water by volume.

Hydrometer.—A hydrometer is used to test the electrolyte solution in the cells of storage batteries. It consists of a weighted float and a graduated stem, and as sulphuric acid is heavier than water, the specific gravity reading will be proportional to the amount of acid. The hydrometer thus measures the relative amount of acid in the electrolyte and consequently reveals the condition of the battery.

Ammeter.—An ammeter is an electrical instrument which indicates the amount of current that the generator is supplying to the storage battery, or the amount of current that the storage battery is supplying for ignition, lights and horn.

Circuit Breaker.—The circuit breaker is a device which prevents excessive discharging of the storage battery. All the current for lights is conducted through the circuit breaker (Delco system). Whenever an excessive current flows through the circuit breaker it intermittently opens the circuit causing a clicking sound. This will continue until the ground is removed or the switch is operated to open the circuit on the grounded wire. When the ground is removed the circuit is automatically restored, there being nothing to replace as is the case with fuses.

Switch.—A switch opens and closes the various circuits and is for the purpose of controlling the light, ignition, generator and storage battery circuits.

Generator.—See chapter on [electrical starting systems].

Regulation.—(Delco). On account of the various speeds at which the generator must operate it is necessary that the output be regulated so that sufficient current is obtained at the low engine speeds without excessive current at the higher speeds. The regulation in this case is what is known as the third brush excitation in which the current for magnetizing the frame is conducted through the auxiliary or third brush on the generator commutator. With this arrangement the natural function of the generator itself causes less current to flow through the shunt field winding at the higher engine speeds. This weakens the magnetic field in which the armature is rotating and decreases the output of the generator.

Contact-breaker.—See chapter on [Atwater Kent ignition systems].

Coil, nonvibrating.—See chapters on [Atwater Kent ignition systems] and [Philbrin electrical systems].

Distributors.—See chapters on [Magnetos] and [Atwater Kent ignition systems].

CHAPTER XV
MAGNETO PARTS AND OPERATION

Fig. 56. Magnets—Pole Blocks

The purpose of the magneto is to furnish electrical current at regular intervals, to jump the spark plug gaps and to ignite the gas which has been compressed in the combustion chambers. The discovery was made years ago that, by placing a coil of wire between two magnetic poles, current would be present at once. But it is only while the wire coil is in motion that the current will flow or circulate, and while there are many theories why this takes place only while the coil is in motion, none seem to explain the fact satisfactorily. The strength of the current depends on the size of the magnetic field, and the number of wraps of wire in the coil. Consequently the larger the coil the more intense the current. [Fig. 56] represents the magnets, of which there are from three to six. The U-shaped pieces are made of steel which has been case hardened and charged with electricity which causes them to become magnetized. Magnets have two poles or axes, one of which is positive from which the current flows, and one of which is negative to which the current flows or passes. [Fig. 56A] shows the pole pieces which are located on the inside of the lower or open end of the magnets. The pole pieces are channel ground, leaving a round space or tunnel in which the armature revolves.

[Fig. 57] shows the soft iron core which is shaped like the block letter H, and wound with fine wire, making up the coil shown in [Fig. 57A] of the wound armature.

Fig. 57. Armature Core—Wound Armature

Fig. 58. Primary and Secondary Winding and Current Direction

[Fig. 58] shows the primary and secondary winding. The primary or heavy wire is wound on the core lengthwise, each strand being separated from the other with rubber or tin foil insulation. The current passes from the top of the left pole piece to the top of the core until it passed out of range, crossing the upper gap between the two pole pieces. As the top of the core leaves or breaks the contact flow of current, the bottom of the core comes in contact range, leaving an open space which breaks the current and changes the direction of flowage as shown in [Fig. 58A and 58B]. This current is of a low tension nature, and will not jump the gap at the spark plugs when the engine is running slow. The secondary winding, shown in [Fig. 58], is made up of many more windings of a finer wire. The low tension or primary current is led through the armature shaft to a contact breaker at the rear of the magneto.

[Fig. 59] shows the contact breaker, which consists of a housing in which two platinum points are arranged, one point stationary, the other attached to an arm on a pivot. The points are held together by spring tension.

Fig. 59. Breaker—Slip Ring—Distributor

A cam on the armature shaft comes into contact with the arm on which the second point is located, forcing it from the stationary point, thus breaking the low tension current which returns to the secondary coil, the magnetizing and demagnetizing caused by the break in the low tension current, and sets up a rapid alternating current. One end of the secondary is led to a collector ring on the front of the magneto. [Fig. 59A] shows the collector ring. A carbon brush collects the current from the ring and conducts it to the distributor’s centrally located arm. [Fig. 59B] shows the distributor. The centrally located arm is timed to deliver the current, or comes into contact with one of the segments or brushes and allows the current to flow from the segment to the gap at the spark plug, where it jumps the gaps and ignites the gas in the cylinders at the proper time. Then it returns through the ground (the engine and the frame) to the magneto, where it passes back into the secondary coil, passing through an insulated condenser consisting of small plates of steel insulated from one another. This regulates the flowage of the returning current, by reducing it through resistance, and prevents the armature from heating.

A safety spark gap is provided on some magnetos which causes the spark to jump and lose some of its force through resistance when the plugs become shorted. This also restricts the current and greatly aids the condenser in performing its purpose.

CHAPTER XVI
BOSCH HIGH TENSION MAGNETO
Operation, Adjustment and Care

Like all other types of high tension magnetos, the Bosch Type ZR. Ed. 16 explained in this chapter, generates its own current and is usually employed as sole ignition on an engine.

The timer and distributor are integral; and the rotation of the armature, between the poles of strong permanent field magnets, sets up or induces a current in the armature primary circuit, which is farther augmented at every one hundred and eighty degrees of revolution of the armature shaft, by the abrupt interruption of the primary circuit by means of the magneto interruptor. At the opening of the primary circuit the resulting discharge of current from this circuit induces a current of high voltage in the armature secondary circuit. The high tension current thus created is collected by a slip ring on the armature and passes to the slip ring brush then to the various magneto distributor terminals each of which is connected to a spark plug in its respective cylinder.

The operation of the instrument will be more clearly understood from a study of the complete circuits, primary and secondary, which follows.

The Primary or Low Tension Circuit.—The beginning of the armature primary circuit is in metallic contact with the armature core, and the end of the primary circuit is connected by means of the interruptor fastening screw to the insulated contact block supporting the long platinum contact on the magneto interruptor. The interruptor lever carrying a short platinum contact, shown in [Fig. 60] at C is mounted on the interruptor disc, which in turn, is connected to the armature core. The primary circuit is completed whenever the two platinum contacts of the interruptor are brought together, and separated whenever these contacts are separated.

From the latter point the high tension current passes to the distributor brush ([shown] at D) which is held in a brush holder on the distributor gear, and consequently rotates with the distributor gear. Metal segments are imbedded in the distributor plate and as the distributor brush rotates it makes successive contacts with the segments, passing the current onto the spark plug gaps through the high tension cables which are attached to the segment terminal posts.

Fig. 60. Bosch M Distributor and Interruptor—Housing Removed

[Fig. 61] shows a circuit diagram of the Type ZR. Ed. 16. Bosch Magneto. Note that the spark plugs must be connected up in accordance with the firing order of the engine. The metal segments imbedded in the distributor plate are connected with the terminal studs on the face of the plate, and the latter are connected by cable to the spark plugs in the various cylinders. In the cylinders the high tension current produces a spark which produces ignition, and then returns through the ground and the engine to the magneto armature, thus completing the circuit.

Timing the Magneto.—With the average four cycle engine the proper operating results are obtained by timing the magneto as follows: The crank shaft is rotated to bring the piston in No. 1 cylinder (in automobile practice this is the cylinder nearest the radiator) exactly on top dead center of the compression stroke. The timing control lever on the housing is then placed in the fully retarded position. With this done, the magneto distributor plate should be removed by withdrawing the two holding screws, or by releasing the two holding springs as the case may be.

			DISTRIBUTOR
BRUSH HOLDER	SAFETY SPARK GAP
SLIPRING		CONDENSER
	ARMATURE			INTERRUPTER
GROUND			GROUND

Fig. 61. Wiring Diagram Bosch Magneto, Type ZR-4

The operation of the platinum contact points is controlled by the action of the interruptor lever as it bears against the two steel segments secured to the inner surface of the interruptor housing.

In [Fig. 60], A shows the distributor with the face plate removed to show the position of the distributor segments which are connected to the terminal posts on the back of the plate. B shows the interruptor housing and cover removed from its position on the magneto. C shows the complete assembly of the distributor and interruptor. Note that the face plate of the distributor is fastened on with a set of screws while the interruptor cover is held in position with a latch.

The Secondary or High Tension Current.—The high tension current is generated in the secondary circuit only when there is an interruption of the primary circuit, the spark being produced at the instant the platinum interruptor contact points separate. The armature secondary circuit is a continuation of the armature primary circuit, the beginning of the secondary circuit being connected to the primary, while the end of the secondary is connected to the insulated current collector ring mounted on the armature just inside the driving shaft end plate of the magneto. The slip ring brush is held in contact with the slip ring by a brush holder at the shaft end of the magneto which receives the high tension current collected by the slip ring by means of a connecting bar which passes under the arch of the magnets, and passes the current to the center of the distributor plate, thus exposing the distributor brush and gear. The cover of the interruptor housing is also to be removed to permit observation of the interruptor points.

The armature should then be rotated by means of the exposed distributor gear in the direction in which it is driven until the platinum contact points are about to separate, which occurs when the interruptor lever begins to bear against one of the steel segments of the interruptor housing. Timing or installation is completed by replacing the interruptor housing cover and distributor plate, and connecting the cables between the magneto and the spark plugs.

Exact Magneto Timing.—The foregoing will establish the desired relationship between the magneto armature shaft and the engine crank shaft. It should be noted, however, that while these instructions cover the average engine, the exact magneto timing for individual engines is best determined by trial.

When specific instructions for magneto timing are given by the engine manufacturer, it is recommended that such instructions be followed in preference to those herein given.

It must always be borne in mind that while making connections the distributor brush travels in the opposite direction to the rotation of the armature shaft.

The Condenser.—The condenser consists of a set of metal discs, insulated from one another with tin foil. It is carried at the interruptor end of the magneto. It is connected in the primary current and forms a shunt connection with the interruptor contact points, and through resistance to the returning ground current prevents excessive sparking at the interruptor contact points which would soon burn the points and ruin the coils.

The Safety Spark Cap.—A safety spark cap is provided to protect the armature and other current carrying parts. Under normal conditions the current will follow its path to the spark plug, but if for any reason the resistance in the secondary wire is increased to a high point, as when a cable becomes disconnected, or a spark gap too wide, the high tension current will discharge across the safety spark gap.

Caution.—The current should never be allowed to pass over the safety spark gap for any length of time, and if the engine is operated on a second or auxiliary ignition system, the magneto must be grounded in order to prevent the production of high tension current. The snapping sound by which the passage of current across the safety spark gap may be noted should always lead to an immediate search for the cause of the difficulty.

The Safety Spark Gap.—The safety spark gap consists of a pointed metal electrode projecting from the mounting flange of the slip ring holder, inside the shaft end hood. The tip of the electrode extends to within a short distance of the connecting bar, extending from the brush holder to a magneto distributor plate center post.

Timing Range.—The magneto interruptor housing is arranged so that it may be rotated through an angle of thirty-four to thirty-seven degrees with respect to the armature shaft. The movement of this housing in one direction or another causes the interruptor lever to strike the steel segments earlier or later in the revolution of the armature, the spark occurring correspondingly earlier or later in the cylinder. The spark can be advanced by means of moving the interruptor housing which is connected to the spark lever on the steering gear, in the direction opposite the rotation of the armature. The armature rotation is usually indicated by an arrow on the cover at the driving end of the magneto.

Cutting Out Ignition.—Since a high tension current is generated only on the interruption of the primary circuit, it is evident that in order to cut out the ignition, it is merely necessary to divert the primary current to a path that is not affected by the action of the magneto interruptor. This is accomplished as follows: An insulated grounding terminal is provided on the cover of the magneto interruptor housing with its inner end consisting of a spring with carbon contact pressing against the head of an interruptor fastening screw. The outer end of the grounding screw is connected by low tension cable to one side of the switch, and the other side of the switch is grounded by connecting a cable between it and the engine or frame. When the switch is open the primary current follows its normal path across the interruptor points, and is interrupted at each separation of these contact points. However, when the switch is closed, the primary current passes from the head of the interruptor fastening screw to the carbon contacts of the grounding terminal, thence through the switch to the engine and back to the magneto, and as the primary current remains uninterrupted when following this path, no ignition current is produced.

Care and Maintenance.—Aside from keeping the magneto clean externally, practically the only care required is the oiling of the bearings. Of these there are two sets supporting the armature, and a single plain bearing supporting the shaft of the distributor gear. Any good light oil may be used for this purpose (never cylinder oil), and each of the bearings should receive not more than two or three drops about every thousand miles. Apply the oil through the oil ducts at each end of the armature shaft. The interruptor is intended to operate without oil, as oil on the interruptor platinum points prevents good contact, and causes sparking, burning, and misfiring. Care should be taken to prevent oil entering these parts.

CHAPTER XVII
MAGNETO WASHING, REPAIRING AND TIMING

One point that cannot be over sufficiently emphasized is the warning that only those who are thoroughly familiar with the magneto should attempt to disassemble it. Therefore every part should be studied, and its functional action fully understood before any repairs or adjustments are undertaken.

The manufacturers of magnetos have developed their product to a point of high efficiency and dependability, and if they are properly lubricated and washed occasionally to prevent gumming up, very little trouble may be expected from this type of ignition system.

Magneto Cleaning.—Magneto parts should be washed with gasoline as it has the ability to remove grease and dirt and evaporates rapidly leaving a perfectly dry surface. Care should be exercised to prevent fire, for the present grade of gasoline does not evaporate as readily as it did some time ago when refiners furnished a high test grade of fuel and the surface of the armature and indentures of the magneto may retain a pool or film which may be ignited by a short circuit, or from the breaker box, and cause a fire which would ruin the magneto. There is, however, little danger from fire if the gasoline is used sparingly, and each part wiped dry before reassembling the magneto.

It is considered a good point when the magneto has been taken apart to be cleaned to go over every part with a cloth dampened in kerosene, because gasoline leaves a very dry surface which is liable to rust. The bearings especially are most easily affected in this way.

The armature may be washed with a brush which has been dipped into gasoline, but should not be immersed as that would soften the insulation and cause it to rot.

The way in which the parts come off should be carefully noted in order to avoid trouble in reassembling, and the gears operating the distributor should be carefully marked to assure correct timing, which will result in a saving of time and trouble.

When the magnets are removed, close the ends with a file or piece of steel to prevent them from becoming demagnetized.

Magneto Repairing.—As previously stated, it is not likely that a magneto will require any further attention than the regular monthly oiling. Two or three drops of light sewing machine oil should be dropped into the oil wells which supply the bearings at each end of the armature shaft.

If any trouble arises that can be traced directly to the magneto, examine the breaker box mechanism first; the locknut at the point adjustment may have worked loose, and the points may be closed, or some abnormal condition may exist that has caused the points to pit and stick.

Breaker point adjustment varies from the thickness of a sheet of writing paper to one sixty-fourth of an inch; an adjustment anywhere between these two points usually results in satisfactory operation.

If the magneto does not function properly after the breaker box and external wire connections have been examined, the trouble is probably due to an internal short circuit, and repairs of this nature should only be undertaken by an expert magneto mechanic.

To remove the magneto, disconnect the high tension wires leading to the spark plugs from the distributor terminal posts, tag and number each wire to correspond with the number stamped below the post. If the engine fires 1-2-4-3, number three wire will be attached to number four terminal post. Then remove the ground wire and disconnect the universal joint and remove the metal strap, or the set screws, from the base.

To Time the Magneto.—Place the timing control lever in a fully retarded position; remove the plates from the distributor housing to expose the distributor brush and gear, then remove the cover from the interruptor housing to permit observation of the points, and rotate the armature in the direction which it is driven until the point begins to open. At this point mesh the distributor gear so that the distributor lever will just be touching one of the segments which connect to the distributor terminal posts.

Timing the Magneto with the Engine.—Rotate the crank shaft until No. 1 cylinder is up on dead center on the compression stroke; rotate the armature, with the spark lever in full retard until the distributor arm begins to make contact with No. 1 segment, and mesh the timing gear at this point.

CHAPTER XVIII
NORTH EAST IGNITION SYSTEM

The N.-E. Model O Distributor Ignition System is used on Dodge Brothers cars. This system provides high tension ignition for the engine by transforming the low voltage of the starter generator or the battery into a high voltage capable of jumping freely between the spark plug electrodes. This is accomplished through the agency of an induction coil, the primary winding of which, in series with an interruptor or contact breaker, receives current under normal running conditions from the starter generator. The starting and lighting battery, however, supplies this current instead of the generator whenever the engine is starting or running very slowly.

At each interruption of the primary current there is set up in the secondary winding of the coil a high tension current, and this current flows from the coil through a high tension cable to the distributor rotor from which point it is selectively conducted to the proper spark plug. Upon reaching the spark gap in the plug, it jumps from the inner electrode to the outer one, which is grounded, and then returns through the engine frame to the grounded end of the secondary winding on the ignition coil. The high tension spark thus produced in the cylinder ignites the gas and so brings about the necessary combustion.

Wiring ([Fig. 62]).—As will be evident upon reference to the accompanying wiring diagram, the primary circuit of the ignition system leads from the positive terminal of the battery through the charging indicator to the ignition switch binding post marked “Bat.,” thence, when the switch is turned on, through the switch to one of its binding posts marked “Ign. Coil.” Continuing on from this point through the ignition coil and the breaker contacts, it returns to the second switch binding post marked “Ign. Coil,” where it passes through the switch again. It then finally reaches the grounded negative terminal of the battery through the grounded terminal of the switch and the car frame.

CHARGING INDICATOR			IGNITION AND LIGHTING SWITCH		SPARK PLUGS
			GROUNDED THROUGH CASE
					CONTACT-STUD LOCK NUT
					STATIONARY CONTACT-STUD
					MANUAL CONTROL LEVER
BREAKER-ARM
GROUND CONNECTION			BREAKER-CAM
STARTING SWITCH AND REVERSE CURRENT CUT-OUT		BREAKER-CAM NUT
					CONDENSER	BREAKER- CONTACTS
			IGNITION COIL		BREAKER BOX		DISTRIBUTOR HEAD
BATTERY		SECONDARY COIL
		PRIMARY COIL		SAFETY SPARK GAP
GROUND CONNECTION			GROUNDED THROUGH CASE

Circuit Diagram of the Model O Ignition System on the Dodge Brothers Motor Car

Fig. 62. Wiring Diagram, North-East System—on Dodge Car

The ignition switch is so constructed that it produces a reversal of polarity in the distributor circuit each time the switch is turned off and then on again. For this reason there is no necessity of making a distinction between the two wires leading from the distributor to the two switch binding posts marked “Ign. Coil,” because the operation of the system cannot be affected by the transposition of these wires. With this one exception, however, the ignition circuit connections must always be made exactly as indicated in the diagrams, if satisfactory operation of the system is to be maintained.

							HIGH TENSION DISTRIBUTOR TERMINALS
DISTRIBUTOR-BRUSH							DISTRIBUTOR-HEAD
DISTRIBUTOR-ROTOR							BREAKER-CAM NUT
BREAKER-ARM							LOCK WASHERS
VERTICAL SHAFT							BREAKER-CAM
VERTICAL SHAFT BEARING SLEEVE							STATIONARY CONTACT-STUD SUPPORT
PRIMARY COIL TERMINALS
							GREASE CUP
							COUPLING YOKE
HIGH TENSION COIL TERMINAL								HORIZONTAL SHAFT
		ADVANCE PLATE
COIL HOUSING						VERTICAL SPIRAL GEAR
		ADVANCE WEIGHTS
IGNITION COIL					HORIZONTAL SPIRAL GEAR

Fig. 63. North-East Distributor—Model O—Ignition

Ignition Distributor. ([Fig. 63]).—The model O ignition distributor is mounted on the right-hand side of the Dodge Brothers engine where it is held rigidly in position by means of four bolts. The horizontal shaft of the distributor is connected directly to the engine pump shaft through a flexible coupling, and runs, therefore, at engine speed. The vertical distributor shaft is driven from the horizontal shaft by means of spiral gears which reduce its speed to one-half that of the engine.

The complete distributor unit consists essentially of three self-contained assemblies: The ignition coil, the breaker box and distributor base assembly which include the automatic spark advancing mechanism. Each one of these three elements is so constructed as to be readily detachable from the distributor unit independently of the others.

Ignition Coil.—The ignition coil, which is contained in a separate housing, forming part of the distributor unit, is constructed for 12 volt service and operates directly on the starting and lighting circuit. The coil housing is attached to the distributor base by means of four screws and serves also as a cover for the automatic advance compartment. The high tension terminal located on the coil housing is designed to provide a safety spark gap, as well as to act as a binding post for the high tension cable which connects the coil to the distributor head.

Breaker Box and Distributor Head Assembly. ([Fig. 64]).—The breaker box and distributor head assembly is mounted in an upright position near the center of the distributor base and is secured in place by a large-headed screw in the vertical portion of the base. This screw projects into the annular groove in the vertical shaft bearing sleeve, thereby preventing the breaker box assembly from becoming detached from the distributor base and yet at the same time permitting it to turn freely from side to side. The short lug projecting downward from the manual control lever on the breaker box extends into the round hole near the middle of the distributor base and acts as a stop to limit the travel of the breaker box.

In case it should become necessary to remove the breaker box and distributor head assembly, the distributor head should first be detached from the breaker box and then, with the breaker box in the position of full retard, the exact location of the distributor rotor should be marked accurately on the edge of the box. This mark should be made with special care, because it has to serve as the sole guide for the correct position of the vertical shaft when the assembly is put back in place again on the distributor base. Moreover, while the breaker box assembly is separated from the base, the horizontal shaft in the base must not be turned from the position it occupied at the time when the location of the rotor was marked. If either of these precautions is neglected, the correct relationship between the several moving parts of the system will be likely to be disturbed to such an extent that the complete retiming of the distributor will become necessary.

Fig. 64. North-East Breaker-Box

Condenser.—The condenser, shunted across the breaker contacts to absorb the inductive surges that occur in the primary circuit at each interruption, serves to intensify the effect produced in the secondary circuit by these interruptions, and also to protect the breaker contacts from injurious arcing. It is contained in a sealed case which protects it against possible external injury, and is located in the breaker box close to the breaker contacts where its maximum effectiveness is obtained.

Being very substantially constructed, the condenser ordinarily requires no attention. If for any reason it should become inoperative, the best course is always to replace it with a new one, because condenser repairs are not economically practicable. The entire condenser unit can be easily removed, whenever desired, by disconnecting the two condenser leads from the breaker box binding posts, and then unscrewing the two nuts on the under side of the breaker box that hold the condenser case in place.

Breaker Contacts.—The breaker arm, which carries one of the two breaker contacts, is mounted on a pivot post from which it is thoroughly insulated by a fiber bushing. The helical spring, which is attached to the lug at the pivot end of the arm, holds it normally in such a position that the breaker contacts are kept closed. But the fiber block near the middle of the breaker arm lies in the path of the breaker cam and is consequently struck by each lobe of the cam as the vertical shaft revolves. Each of these blows from the cam cause the breaker contacts to be forced apart, and thereby produce the necessary interruptions in the primary circuit. The second contact is carried by the stationary contact stud, which is adjustably mounted in an arched support. With this stud properly adjusted the difference between the contact points when they are fully separated by the cam, is twenty thousandths of an inch (.020″).

If it should ever become necessary to renew the breaker contacts, a complete replacement of the entire breaker arm and the contact stud assemblies will in general be found to be the most effectual method of handling the work. The breaker arm can be removed by simply lifting it off its pivot bearing after its pigtail has been disconnected from the breaker box binding post. The spring attached to the breaker arm lug will slip off of its own accord as soon as the arm is raised sufficiently from its normal position. After the breaker arm has been taken off, the stationary contact stud can be removed by releasing its lock nut and unscrewing it from its support. To replace the breaker arm it is merely necessary to insert the lug in the spring, and then, with the spring held taut, to push the arm firmly down upon its pivot post until it snaps into position.

Breaker Cam.—The breaker cam, by which the interruptions in the primary circuit are produced has four projections on its working surface, so spaced that one of them strikes the breaker arm and causes the breaker contacts to be abruptly separated each time a spark is required. The cam is held in place on the upper end of the vertical shaft by means of a slotted nut and set of special lock washers. It should never be disturbed if avoidable, because its accurate setting is absolutely essential to the correct operation of the entire system. If, at any time, however, its position should become altered accidentally, it must be carefully reset at once in accordance with the timing directions given later on.

The breaker cam and the distributor rotor are both mounted on the vertical shaft and are rotated at exactly one-half engine speed. Accordingly, since the engine is of the usual four-cycle type requiring two revolutions of the crank shaft for one complete cycle of operation, the distributor rotor and breaker can make one revolution during the completion of each full cycle of the engine.

Distributor Head.—The distributor head contains five high tension terminals. The central terminal receives the current from the secondary winding of the ignition coil and transmits it to the rotor arm by which it is distributed to the four outer terminals. These outer terminals are numbered 1, 2, 3, 4 respectively, corresponding to the firing order of the engine, and are connected to the four spark plugs in accordance with their markings. The distributor rotor in completing one full revolution establishes contact successively between the rotor brush and each one of these four outer distributor terminals, each contact being made at the same moment that the primary circuit is interrupted by the action of the breaker cam. Thus when the spark plug leads are properly connected, the high tension current, as soon as produced in the secondary circuit, is conducted to the spark plug of the proper cylinder just at the moment when the gas in that particular cylinder is ready for firing. If, therefore, the spark plug leads ever have to be removed from the distributor head, they must always be attached again carefully in the correct order.

Automatic Advance Mechanism. ([Fig. 65]).—Combustion does not follow instantaneously upon the occurrence of the spark, however, because a small time interval is always needed for the gas in the cylinder to ignite. Consequently, unless some means are provided for offsetting the lag between spark and combustion, the explosion of the gas could not always be made to take place at exactly the correct moment under varying conditions of engine speed.

Fig. 65. Automatic Spark Advance Mechanism—North East

To compensate for this lag, therefore, there is incorporated in the distributor a centrifugally actuated mechanism, which is capable of automatically advancing or retarding the time of the spark in exact accordance with the rate of speed at which the engine is running.

The operating characteristics of the automatic advance are accurately proportioned to conform throughout the entire speed range with the requirements of the engine; and in order to insure the permanence of this relationship the device is so constructed as to be practically nonadjustable.

Manual Spark Control.—Besides this automatic advance there is also the usual manual control mechanism for changing the time of the spark independently of the centrifugal device. This manual control is for use principally for retarding the spark when starting or idling the engine or for facilitating carburetor adjustments. During normal operation of the engine, the spark lever on the steering wheel quadrant should be advanced as far as permissible without causing the engine to knock, and the actual regulation of the spark position be left entirely to the automatic advance mechanism. The arrangement of the manual control is such, provided the breaker cam is properly set, that when the spark lever is in the position of full retard, and the engine is running very slowly, the spark will occur in each cylinder at 5 engine degrees after the piston has passed the upper dead center of its compression stroke. With the spark lever advanced to the limit of its travel on the quadrant, the spark will occur 15 degrees before the upper dead center position has been reached by the piston on its compression stroke.

Timing the Distributor.—Whenever it becomes necessary to disconnect the distributor shaft from the engine pump shaft the exact relative positions of the two halves of the coupling joining these two shafts, as well as the location of the distributor rotor, should be carefully noted and marked. This is necessary in order to make possible the reëstablishment of the correct relations between the distributor shaft and the pump shaft when original conditions are being restored. Moreover, care must be taken to avoid turning the engine while the distributor is disconnected, because the proper timing relations can only be retained by keeping the position of the pump shaft unchanged during this time.

Should it ever happen, however, that the distributor has been taken off without the proper precautions having been observed, or that the timing arrangement has been disturbed in any other fashion, it will thereupon become necessary to make a complete readjustment of the timing relations of the distributor and the engine. This is to be done always after the distributor has been reconnected to the engine, the first step being to ascertain definitely the relative position of the engine pistons and valves. With this done, the positions of the breaker cam and the distributor rotor are then to be reset as directed below.

Since all the parts of the engine follow a regular sequence of operation, only the position of the piston and valves in the No. 1 cylinder need be considered in this process, and the three remaining cylinders may be practically disregarded. There are numerous methods, varying in their degree of accuracy, for locating the position of the engine pistons, but the most dependable one is that of removing the cylinder head so as to expose the pistons and valves to full view. With the head thus removed, the engine should be cranked slowly by hand until the No. 1 piston has risen to the top of its compression stroke and has just started to descend on its combustion stroke. At this moment the spark, when fully retarded, should normally occur in No. 1 cylinder.

Under circumstances where it is not convenient or desirable to remove the cylinder head the following approximate method for determining the location of No. 1 piston may be employed with a fair degree of success. Open the cocks of the priming cups on all the cylinders, and crank the engine slowly by hand until the No. 1 piston has just reached the top of its compression stroke. This can be ascertained by holding the thumb over the No. 1 priming cup and noting carefully the moment when the compression ceases to increase. After locating the dead center position of No. 1 piston in this way, turn the crank shaft a very slight distance further until the No. 4 exhaust valve is just at the point of closing. Under these conditions, provided the No. 4 exhaust valve lifter is in correct adjustment, the No. 1 piston should be approximately in the desired position of 5 engine degrees beyond dead center.

With the No. 1 piston thus carefully set in accordance with one of the above methods, preferably the former, bring the distributor into the position of full retard. To do this, disconnect the manual control attachment and turn the break-box as far as it will go in the direction in which the vertical shaft rotates. Then after making sure that the ignition switch is turned off, remove the distributor-head and the distributor rotor and the breaker box, and with a broad bladed screw driver back off the breaker cam nut until the cam is free to turn on its shaft. Next, replace the rotor temporarily, and turn the cam slowly until the breaker contacts just begin to open when the rotor occupies the position where it normally makes contact with the No. 1 distributor terminal. This adjustment can be made to the best advantage by turning the cam forward to separate the contacts then back again slowly until the contacts just come together, at which point the cam should be allowed to remain.

After the proper setting has thus been obtained, remove the rotor again and lock the cam securely in position by tightening the slotted nut that holds it. Finally, replacing the rotor, rock the vertical shaft backward and forward as far as the slack in the gears will permit, and note carefully the action of the break contacts. The setting of the cam must be so accurate that when the gears are rocked forward to take up the slack, the contacts will be just held apart and yet when the gears are rocked backward as far as the slack permits, the contacts will be actually closed.

A convenient method of verifying this adjustment is to turn on the ignition current and connect an ordinary 14 or 16 volt 2. c. p. lamp across the two binding posts of the breaker box. The lamp thus attached, will serve as a sensitive indicator for representing the action of the contact-points when the vertical shaft is rocked forward and backward to take up the slack in the gears. The moment the contacts begin to be separated, the lamp will light; but as soon as they are allowed to come together the lamp will at once go out again.

Should the test prove the first setting to be inaccurate, the cam must be readjusted, and the test repeated several times if necessary until the correct setting is finally obtained. Too much care cannot be employed in making this adjustment, because even a very slight inaccuracy in the setting of the cam will produce a considerably magnified effect upon the operation of the engine. This is due to the fact that the engine speed is twice as great as that of the vertical shaft.

General Care.—Under normal operating conditions the ignition system requires very little care aside from the usual precautions against moisture and dirt. There are, in fact, but three points of importance that need attention during service:

1. Lubrication.

2. Cleaning and adjustment of the breaker contacts.

3. Inspection of the wiring and the spark plugs.

CHAPTER XIX
ATWATER KENT IGNITION SYSTEMS
Construction, Operation and Care

Atwater Kent ignition systems have been adopted of late by many prominent automobile manufacturers as a means of distributing or conveying electrical spark to the cylinders at the proper firing time.

This type of quick break distributing system has proved very efficient and dependable, and will usually outlast the life of the motor as there are very few moving parts, which eliminates troubles caused by worn parts getting out of adjustment.

This type of ignition system operates in much the same manner as the high tension magneto, and differs only in that the parts have been taken from the compact magneto case and distributed in other locations in separate units. As this type takes its current from the lighting and starting battery, it does not contain an armature or field magnets to manufacture the electrical force.

[Fig. 66] illustrates the principles of operation of the type CC Atwater Kent closed circuit system, which consists of the unisparker containing the contact maker and distributor. The only moving parts are located in this unit. The coil consists of a soft iron core, with a primary and secondary winding sealed in an insulated tube or container. A resistance unit is located in the top and regulates the current automatically. The system is controlled by a switch located on the dash. The contact breaker shown in [Fig. 67] consists of an exceedingly light steel contact arm. One end rests on a hardened steel cam which rotates one-half as fast as the crank shaft. This cam has as many sides as the engine has cylinders. When the contact points are opened by the movement of the cam the primary circuit is broken and produces a discharge of secondary high tension current at one of the spark plug gaps.

CONTACT MAKER	TO PLUG TO PLUG
	DISTRIBUTOR
CONDENSER
	TO PLUG
CONTACT MAKER GROUNDED
	SPARK PLUG
BATTERY GROUND
PRIMARY
BATTERY	GROUND
SWITCH
SECONDARY
	GROUND
REGULATING RESISTANCE

Fig. 66. Atwater Kent Circuit Diagram—Type CC

[Fig. 68] shows the simple Atwater Kent contactless distributor. The high tension distributor of the Atwater-Kent system forms the top of the contact maker. Each spark plug wire terminates in an electrode, which passes through the distributor cap. A rotating distributor block takes the high tension current from the central terminal and distributes it to the spark plugs in proper firing order. The distributor block or arm does not make direct contact with the distributor posts. The current jumps the small gap between the distributor block and the terminal electrodes and does away with frictional wear resulting from actual contact.

Fig. 67. Atwater Kent Contact Breaker—Type CC

Fig. 68. Atwater Kent Distributor and Contactless Block

[Fig. 69] shows the method of connecting the high tension wires to the distributor; the insulation is removed, or the wire bared in a space 1¹⁄₄″ long. The removable terminal cover is pushed up on the wire as shown at A, the bared end of the wire is then passed through the hole in the secondary terminal as shown at B. The end of this wire is then twisted back on itself, for two complete turns as shown at C, so that the end will not project beyond the diameter of the insulation. The wire will then be tightly held when the terminal covers are screwed down as shown in Fig. D. Never use pliers to tighten these covers and do not solder the wires to the terminal posts.

Fig. 69. Distributor Wire Connections to Distributor

Adjustment.—The only parts of this system that are adjustable are the contact points. These need to be adjusted only for natural wear. Do not adjust the points unless you are convinced, by trying everything else, that it is the points that need attention.

In making adjustments, note the following directions. The normal gap between the points should not be less than .005″, or more than .008″, the standard setting is .006″, which is about the thickness of two ordinary sheets of writing paper.

TO UNGROUNDED
TERMINAL OF BATTERY

SWITCH

COIL

DISTRIBUTOR

GROUND

CONTACT
MAKER

Fig. 70. Atwater Kent Type CC Wiring Diagram

The contact points are made of tungsten steel, the hardest known metal. When contact points are working properly small particles of tungsten steel will be carried from one point to the other, which sometimes causes a roughness and a dark gray coloring of the surfaces. This roughness does not in any way effect the proper working of the points, owing to the fact that the rough surfaces fit into each other perfectly.

It should not be necessary to file or redress the points unless they become burned, due to some abnormal condition or accident. The dark gray appearance is the natural color of the tungsten steel.

Oilings.—A very small amount of ordinary vaseline or grease applied to the cam and a drop or two of oil applied to the cups every few weeks, is all the lubrication necessary. Do not get oil on the contact points, and wipe off any free oil or grease on the contact maker.

The springs in this system are set at exactly the right tension. Do not try to bend or tamper with them.

The wiring of the type CC ignition system is very simple, as shown in [Fig. 70], and is known as the one wire with ground return method. Well insulated primary wire is used for the primary circuit between the coil and the ignition switch. The best quality of five-sixteenth inch secondary wire is used to conduct the high tension current from the coil to the distributor, and from the distributor to the spark plug.

Setting or Timing the Type CC System.—The piston in number one cylinder should be raised to high dead center, between the compression and firing strokes, the clamp which holds the unisparker should be loosened and the unisparker turned backward, or opposite the rotating direction of the timer shaft until the contact points commence to open. The spark occurs at the exact instant of the opening of the point.

After completing the electrical connection the current can be turned on, and the unisparker timed exactly from the spark at the plugs. For this purpose the plugs should be removed from the engine and laid on top of the cylinders.

CHAPTER XX
ATWATER KENT IGNITION SYSTEM, TYPE K-2

The operating principle of the Atwater Kent ignition system type K-2, differs from type CC system in that it operates on the open circuit plan, whereas the type CC system explained in the preceding chapter, operates on the closed circuit plan.

A-K ignition system type K-2 consists of three parts:

No. 1. The unisparker combining the special contact maker, a condenser, and a high tension distributor.

No. 2. The coil, consisting of a simple primary and secondary winding, and a condenser. These parts are all imbedded in a special insulating compound. The coil has no vibrator or other moving parts.

No. 3. The ignition switch. This switch controls the system by opening and closing the primary current.

The Principle of the Atwater Kent System.—The function of this system is to produce a single hot spark for each power impulse of the motor. It differs from other types of battery ignition systems in that the contact points do not touch except during the brief instant of the spark. The ignition circuit is, therefore, normally open, whence the name “open circuit” results. The contact maker consists of a pair of contact points, normally open, which are connected in series with a battery, and the primary circuit of the non-vibrating induction coil. The mechanism for operating the contacts consists of a notched shaft having one notch for each cylinder, rotating at one-half the engine speed, a lifter which is pulled forward by the rotation of the shaft, and a coil spring which pulls the lifter back to its original position after it has been drawn forward and released by the notched shaft; hardened steel latch, against which the lifter strikes on its recoil and which in turn operates the contact points.

	LATCH
CONTACT SCREW		NOTCHED SHAFT
		LIFTER
CONTACT SPRING		LIFTER SPRING

Fig. 71. Atwater Kent Contact Breaker—Diagram of Action—Type K-2 System.

Fig. 72. Atwater Kent Contact Breaker—Diagram of Action—Type K-2 System

Fig. 73. Atwater Kent Contact Breaker—Diagram of Action—Type K-2 System

Fig. 74. Atwater Kent Contact Breaker—Diagram of Action—Type K-2 System

Operation of the Contact Maker.—It will be noted in [Fig. 71] that the lifter is being pulled forward by the notched shaft. When pulled forward as far as the shaft will carry it ([Fig. 72]), the lifter is suddenly pulled back by the lifter spring. In returning, it strikes against the latch, throwing this against the contact spring and closes the contact for a brief instant. This movement is far too quick for the naked eye to follow ([Fig. 73]).

[Fig. 74] shows the lifter ready to be pulled forward by the next notch.

Note that the circuit is closed only during the brief instant of the spark. No current can flow at any other time, not even if the switch is left on when the motor is not running. No matter how slow or how fast the notched shaft is turning, the lifter spring will always pull the lifter back at exactly the same speed, so that the operation of the contact, and therefore the spark, will always be the same no matter how fast or how slow the engine is running. The brief instant that the contact points touch, results in very little current consumption. The high tension current from the coil is conveyed to the rotating distributor block, which seats on the end of the unisparker shaft to each of the spark plug terminals in the order of firing.

Fig. 75. Atwater Kent Distributor and Contactless Block

The important advantage which the distributor possesses is the fact that there are no sliding contacts or carbon brushes. The distributor blade is so arranged that it passes close to the spark plug terminals without quite touching (as shown in [Fig. 75]), thus permitting the spark to jump the slight gap without any loss of current pressure. This also eliminates all wear and trouble caused by sliding or rubbing contacts.

[Fig. 76] shows the wire connections and direction of current flowage. The distributor blade is about to make contact with the terminal leading to the spark plug in No. 2 cylinder. At the instant that contact is made the breaker points in the contact maker shown in the lower part of the diagram close, thus allowing a primary or low tension current to flow between the contact maker, coil, and battery. The sudden breaking of this current occurs when the points open again, thereby creating a current of high tension voltage in the secondary coil which is conducted to the center terminal of the distributor where it is distributed to the spark plug terminals through the rotation of the distributor blade. The high tension cables leading from the distributor are heavily insulated, thus the current in seeking ground return chooses the easiest path, by jumping the slight gap at the spark plugs.

DISTRIBUTOR

GROUND

COIL

BATTERY

CONTACT MAKER

Fig. 76. Atwater Kent Wiring Diagram Type K-2

Setting and Timing the Unisparker.—The type K-2 unisparker is installed, so as to allow a small amount of angular movement or, in other words, the socket into which the unisparker fits is provided with a clamp which will permit it to be turned or locked in any given position.

Timing.—The piston in No. 1 cylinder is raised to high dead center between the compression and power stroke. Then loosen the clamp which holds the unisparker and turn the unisparker backward, or contrary to the direction of rotation until a click is heard. This click happens at the exact instant of the spark. Clamp the unisparker tight at this point being careful not to change its position. Note that current for this system is usually supplied by the starting and lighting battery. When changing batteries be sure that the voltage of the battery is the same as that marked on the coil.

	To Plugs
To Plugs
Contact- maker
Switch	Contact Maker
BAT.
S & INT. INT. S.	INT. INT.
COIL	SEC
	Ground To Motor
Ground to Motor	POS NEG
	BATTERY

Fig. 77. Atwater Kent K-2 Wiring—Cut 1, Under Hood Coil; Cut 2, Kick Switch Coil

The external wiring of the A-K type K-2 is very simple, as shown in the diagrams, [Figs. 77 and 77A]. Fig. 77 shows the wire connections, when the reversing switch and under-hood coil is used. Fig. 77A shows the connections, when using plate or kick switch coil. A well insulated braided primary wire is used for the primary or battery circuit. See that this wire is well protected against rubbing or abrasion wherever it comes into contact with metal parts of the car. When the starting and lighting battery is used to furnish the ignition current, two wires should run directly to the battery terminals.

The two types of Atwater Kent systems described are provided with automatic spark advance mechanism. Provisions are also made for manual lever control, by simply connecting the unisparker to the throttle lever at the base of the steering gear.

Fig. 78. Atwater Kent Automatic Spark Advance Mechanism—A K Type K-2

[Fig. 78] shows the automatic spark advance mechanism. It is located on the underside of the contact maker base plate, and consists of a set of weights which swing out from the center against spring tension, and advances the unisparker on the shaft, according to the amount of centrifugal action or speed of the shaft. When the shaft is not in motion the springs draw the weights toward center, which automatically shifts the unisparker on the shaft until the spark is in a fully retarded position.

Contact Point Adjustment.—The only adjustment aside from the initial timing is in the contact points. They are adjustable only for natural wear, and one adjustment should last at least six months. The contact screw is provided with a number of shim washers against which it is set up tight. When the points eventually become worn, they should be dressed flat and smooth. A sufficient number of the washers should be removed so that when the contact screw is set up tightly it will maintain the proper gap between the points. The distance between the contact points should be about the distance of a thin visiting card. They should never touch when at rest.

Oil lightly every
1000 miles

Oil

Fig. 79. Atwater Kent Contact Breaker—Oiling Diagram—A-K Type K-2

[Fig. 79] shows an oiling diagram of the contact maker. The latch, lifter, and lifter spring are not adjustable or subject to wear. They should be well cleaned and oiled every five hundred miles. Use a light oil and avoid getting it on the contact points.

The Condenser.—The condenser of this system acts somewhat like a shock absorber to the contact points. It absorbs the spark or arc and makes the break in the primary current, clean and abrupt. The condenser is very accessible, but should never be tampered with, as it does not require any attention.

Testing for Ignition Trouble.—If the engine misses without regard to speed, test each cylinder separately by short circuiting the plug with a screw driver, allowing a spark to jump. If all cylinders produce a good regular spark the trouble is not with the ignition system.

If any cylinder sparks regularly this will indicate that the ignition system is in working order so far as the unisparker and coil are concerned. The trouble is probably in the high tension wiring between the distributor and plug, or in the plugs themselves. Examine the plugs and wiring carefully. Leaky secondary wiring is frequently the cause of missing and backfiring.

Frequently, when high tension wires are run from the distributor to the spark plugs through a metal tube, trouble is experienced with missing and backfiring, which is due to induction between the various wires in the tube. This is especially likely to happen if the main secondary wire from the distributor to the coil runs through this tube with the spark plug wires.

Whenever possible the distributor wires should be separated by at least one-half inch of space. They should be supported by bracket insulators, rather than run through a tube. In no case should the main distributor wire run through a conduit with other wires.

If irregular sparking is noted at the spark plugs, examine the battery and connections.

If the trouble commences suddenly, it is probably due to a loose connection in the wiring, if gradually, the battery may be weakening or the contact points may require attention.

CHAPTER XXI
PHILBRIN SINGLE SPARK IGNITION SYSTEM
Operation, Adjustment and Care

The Philbrin ignition system consists of a specially designed contact maker and interrupter, a distributor mounted on the same shaft, a nonvibrating heat and moisture proof coil, an armored heat, moisture, and puncture proof condenser, and a special Duplex switch.

Fig. 80. Philbrin Contact Maker—Point Adjustment

[Fig. 80] shows an illustration of the Philbrin contact maker which operates in this manner. The cam A strikes against the end of the plunger B and forces the points together at C, and holds the contact for approximately three and one-half degrees of the revolution of the cam. The spark occurs simultaneously with the separation of the contact points. The contact maker has but one adjustment; that of the adjustable contact screw, which is in direct line with the contact plunger. The contact points are brought together gradually by the surface formation of the cam. When the point of ample saturation of the coil is reached, the breaking of the contacts is instantaneous. The duration of the spark is in proportion to the speed of the engine, but breaking of the points is always instantaneous and entirely independent of the engine’s speed thereby producing the required spark at all speeds without any spark lag.

Fig. 81. Philbrin Contact Maker and Distributor Blade

[Fig. 81] shows the distributor blade mounted over the contact maker. The distributor blade is so arranged that it clears the spark plug lead terminals in the cover by a slight margin, and does not make actual contact, thereby eliminating all friction due to such contacts.

Operation.—Turning on the switch sets up a low tension current in the coil and primary wire coil when the contact points close. The sudden breaking of this current causes demagnetism of the core and the primary coil to set up a high tension current in the secondary coil. This current is led to the distributor blade and passes to the spark plug terminals as the blade comes in contact range.

The Philbrin high frequency system uses the same coil and distributor as the single spark system. But as the circuits of the two systems are entirely distinct and separate, they do not conflict with each other. The high frequency system has its own condenser and interrupter located in the switch case, and supplies a continuous flow of sparks.

Fig. 82. Switch Case

[Fig. 82] shows the interior of the switch case. This part of the mechanism controls the interruption of the battery current. The current is supplied to the interruptor through a polarity reverser, which reverses the direction of the current each time the switch button is turned. This equalizes the wear on the contact points.

Attention is again called to the distributor blade shown in [Fig. 82], which is used for both systems. Because of the shape of this blade, there is a continuous flow of sparks after the explosive spark has been delivered to one cylinder until the forward edge of the distributor blade is within range of the distributing point of the next terminal. By this action the first spark delivered to the cylinder is an efficient one, and the follow up continues at intervals of approximately one-thousandth of a second. These sparks are all perfectly synchronous.

The operation of the high frequency system does not differ in function action from the single spark system explained on the foregoing page. Either system may be had singly, or in duplex formation. Consequently either the single or the double system may be encountered. When the duplex system is used the driver has his choice and can use either the high frequency or single spark system, by turning the rubber roll switch on the distributor to the system indicated.

This follow-up feature has been found particularly advantageous for starting in cold weather, or where a poor grade of gasoline is encountered, and in case of a poor carburetor adjustment or foul spark plugs. The high frequency system also has the unique feature of keeping the spark plugs clean without disintegrating the electroids, as is often the case with the high tension magneto.

Fig. 83. Duplex High Frequency Switch

[Fig. 83] shows the Duplex switch. Ordinarily a storage battery is used for one source of current, and a set of dry cells for the other. This is so arranged that either source of current can be used with either the single spark system or the high frequency system at will. One source of current only can be used if so desired, that is, the storage battery only or the dry cells alone. Where the source of current is dry cells only, the single spark system is used as it is more economical in current consumption. All of the switch contacts are of the pressure plunger type, thereby eliminating the uncertainty of brush contacts. Each switch is provided with a lock operating through the hub of the lever. When the switch is locked in the off position it is impossible to remove the cover without breaking it as the cover of the switch locks to the back.

Ratchet buttons select which one of the systems is to be used, by a movement of 45°. This button operates only in a clock-wise direction.

						C-2 Circuit 2 C-1 Circuit 1 Bat.-1 Battery 1 Bat-2 Battery 2 Sec-Secondary C-Circuit Sec. Gr. Secondary Ground
			To Spark Plugs		BAT. (SEC.GR.) C
BAT.-2
		BAT.-1			Coil
	C.R.
				Distributor

Fig. 84. Philbrin Wiring Diagram

[Fig. 84] shows a wiring diagram of the Philbrin system. The wire connections come to the contact maker directly from the switch, instead of from the coil. This provides for control of the current to the contact maker in such a manner that if a short circuit occurs in either of the systems, by turning a button it is entirely cut off and the other system put into operation.

Tungsten contact points are used on the single spark system as they are not effected by the use of light oil. The contact points for the high frequency system are platinum-iridium. They are mounted inside of the switch case and need little or no attention. The contacts, due to the reversed polarity, have an extremely long life and can be used without attention until they are worn down to the base metal. The duel type of system, however, may be purchased in separate units, and an owner may choose either the high frequency system or the single spark system separately if so desired.

This type of ignition system is manufactured for four, six, eight, and twelve cylindered cars.

CHAPTER XXII
ELECTRICAL STARTING AND LIGHTING SYSTEMS
Construction, Operation and Care

A great many different types of mechanical, and compressed air starters were devised and tried out as equipment by the manufacturers of automobiles a few years ago. These devices were either mechanically imperfect, or required considerable attention from the owner to keep them in working order and have all but disappeared from the market, being supplanted by the electrical starter, which has been perfected to a high state of efficiency and dependability.

The general principle of all electrical starters is much alike and they usually operate in much the same manner. The electrical force or current is produced by a generator driven from the engine. This current is collected, or held in storage by chemical reproduction plates in a storage battery. The battery, in turn, is connected to a small electric motor carried at the side of the engine.

The Generator.—The operating principle of current production of the generator is practically the same as explained in the magneto, which may also be termed a generator or dynamo.

A generator consists of an iron frame, a set of magnetic field windings, a wound armature with a commutator on the end, and a brush which collects the current from the commutator.

The current is induced in the armature by rotating it in a magnetic field. The amount of voltage induced in the armature-coil depends on its rotating speed, as the faster the armature turns, the greater the number of magnetic field lines cut, and the greater the amount of voltage induced in the armature coil.

The Regulator.—The generator is provided with a regulator to control the output rate of voltage when the engine is running at excess speeds. This is necessary to prevent the higher charging rate from overcoming the capacity of the storage battery. The regulating of the voltage output may be accomplished by mechanical or electrical means. The mechanical regulator usually consists of a governor which is timed to release the armature from the drive shaft when the engine reaches a certain rate of speed. The electrical regulator usually consists of a reversed series of field winding which acts against the force of the magnetic field, or of a bucking coil.

The Automatic Cut-out.—All types of generators which supply current to a storage battery are equipped with an automatic cut-out arrangement which is entirely automatic in action and requires no attention.

The function of the automatic cut-out is to prevent the current from flowing back to the generator when the current production of the generator is less than the charged strength of the storage battery. The cut-out may be located anywhere on the conductor, between the storage battery and the generator, and consists of a simple electro-magnet, which is operated by the direction of current flowage.

One Unit System.—The generator furnishes the current for ignition and starting, and is also reversible to act as a starting motor. The system is referred to as a one unit system.

Two Unit System.—When the starting motor and the generator act singly, and are contained in a separate casting, the system is referred to as a two unit system.

Three Unit System.—When the generator and starting motor are located as a separate unit, and when the ignition current is supplied by a magneto, this system is referred to as a three unit system.

The Starting Motor.—The starting motor is constructed in the same manner as the generator, and is simply a reversal of action. When cranking, the current from the storage battery flows through the motor winding and magnetizes the armature core. This acting upon the magnetism of the frame causes the turning effort.

Lubrication.—Regularly every two weeks, or every five hundred miles, two or three drops of thin neutral oil should be dropped into the oil wells supplying the armature bearings and usually located at each end of the armature shaft.

Fig. 85. Bijur 2-V System Mounted on Hupmobile Engine

Care.—Regularly every two weeks, inspect all connections as a full volume of current will not flow over a loose or corroded connection. Never allow any oil or dirt to collect on the motor or generator, as it interferes with the terminal connection and misdirects the current, and the instrument soon becomes inoperative.

[Fig. 85] shows the location of the two unit Bijur electrical starting and generating system mounted on an engine. The starting motor is bolted to the flywheel housing, and is provided with a square armature shaft which carries a pinion which can be moved horizontally on the shaft. This pinion meshes directly with teeth cut in the steel flywheel ring. No intermediate gears or roller clutches are used. The control lever connects through linkage to the shifting fork which shifts the pinion on the square shaft of the motor. The same foot pedal linkage operates the starting switch. Normally a spring holds the motor pinion out of mesh with the flywheel teeth and also holds the starting switch in the “off” position.

The Generator.—The generator is bolted to an extension on the crank case at the front side of the gas motor, and is driven by a silent chain from the crank shaft. After the gas motor attains a speed equivalent to a car speed of ten miles per hour on high speed, the generator begins to generate, and will generate a current which is highest at low speeds, and diminishes somewhat at higher speeds.

The machines are both self-contained as there are no regulators or automatic switches which require separate mounting.

The automatic switch for opening and closing the circuit between the generator and storage battery is mounted inside the generator. This switch is properly adjusted before the generator leaves the factory, and no further adjustments are necessary.

Two wires lead from the generator. One of these is connected at the starting motor to one of the heavy cables coming from the storage battery, while the other generator wire is grounded on the chassis, the chassis forming a part of the circuit. The generator polarity is reversible and the connections at the machine may be made haphazard and without regard to polarity. If connections are reversed at the generator, no damage will result, as the machine will automatically assume the correct polarity to charge the battery.

[Fig. 86] shows the position of the Bijur starting system, and the relative neutral positions of starting pedal, motor pinion, and starting switch, when the starting equipment is not in action.

[Fig. 86A] shows the normal position of the various parts after the starting pedal has been depressed and just before the starting motor begins to operate. The pinion is now in full mesh with the flywheel ring and further depressing the starter pedal will close the switch.

									FOOT PEDAL
POSITION 1--OUT OF ACTION. STARTING SWITCH OFF. PINION UP AGAINST MOTOR HEAD.							FLYWHEEL
SHIFTING FORK						STARTING SWITCH MOTOR SHAFT
OIL HERE	MOTOR										OIL HERE
											COLLAR
											CLEVIS PIN
					SHIFTING ROD
					STOP	SHIFTER SPRING
										RELEASE SPRING
	OIL DRAIN KEEP THIS HOLE CLEAR		PINION					OIL HERE
CRANK CASE

POSITION 2--ABOUT TO CRANK.
GEARS HAVE MESHED BUT
SWITCH HAS NOT YET MADE CONTACT.

Fig. 86. Bijur Starter Mechanism Showing Action

[Fig. 87] shows all the parts in their positions for cranking. The small gap between the collar on the shifting rod and clevis pin permits the switch rod to move and thus open the starting switch without moving the motor pinion when the starting pedal is released.

POSITION 2A—ABOUT TO CRANK.
GEARS NOT YET MESHED, TEETH
ARE BUTTING, BUT SWITCH HAS
MADE CONTACT. SHIFTER SPRING
STRONGLY COMPRESSED READY
TO DRAW PINION INTO MESH.

POSITION 3—CRANKING, NOTE
GAP BETWEEN COLLAR ON
SHIFTING ROD AND CLEVIS PIN.
SHIFTING FORK IS UP AGAINST
STOP AND SHIFTER SPRING IS
SLIGHTLY COMPRESSED.

Fig. 87. Bijur Starter Mechanism Showing Action

[Fig. 87A] shows the condition when on depressing the foot pedal, and sliding the pinion on the motor shaft towards the flywheel the pinion does not mesh with the flywheel, and the teeth butt. Depressing the foot pedal will close the starting switch strongly compressing the shifter spring. After the switch is closed the motor will begin to rotate and allow the pinion to slip into mesh with the flywheel. The motor will then crank in the normal way.

HEAD LAMP		MOTOR	SWITCH TERMINAL GROUNDED
	GENERATOR		STARTING SWITCH	BATTERY
		IGNITION SWITCH
INTERRUPTOR AND DISTRIBUTOR
	SPARK PLUGS
				REAR LAMP
	HORN		COIL
				INSTRUMENT LAMP
HEAD LAMP		HORN BUTTON	LIGHTING SWITCH

Fig. 88. Wiring Diagram Model N—Hupmobile

[Fig. 88] shows a complete diagram of the Model N Hupmobile wiring system.

CHAPTER XXIII
ELECTRIC STARTING AND LIGHTING EQUIPMENT

[Fig. 89] shows a diagram of the Bijur lighting and starting system on the Jeffrey “Chesterfield-six.” The generator supplies current for the lights and charges a storage battery when the gas motor is running at speeds equivalent to ten or more miles per hour on high gear.

When the gas motor is running at speeds corresponding to less than ten miles per hour, all currents for lamps are drawn from the storage battery.

The starting motor is in operation only during the period of starting, and remains idle at all other times. The appliances shown in the [diagram] constituting the equipment are a six volt constant voltage generator, a six volt starting motor, starting switch, six volt hundred ampere hour battery, lamp controller, and a high tension magneto. Due to the reversible characteristics of the generator, no attention need be paid to the polarity of the wiring when it is removed and again replaced.

The starting motor pinion meshes with teeth on the flywheel when the starting switch mounted on the housing covering the motor pinion is compressed.

Operation of System Shown in Diagram.—After the gas motor reaches a speed equivalent to a car speed of approximately ten miles per hour on the third speed gear, the generator will generate and maintain a constant voltage, or electrical pressure at higher speeds and will also maintain this pressure constant at all loads.

The current output from the generator at any time will depend upon the condition of the storage battery. If a car has been left standing for some time with the lights burning, the storage battery will become more or less discharged and its voltage lowered. Under these conditions the generator voltage or pressure will be higher than that of the battery, forcing a comparatively high charging current into the battery. This current may be from 5 to 20 amperes, and the battery will rapidly approach the fully charged condition.

3⁄8 LOOM		No. 14No. 10	3⁄8 LOOM	No. 14No. 10	1⁄4 LOOM
						No. 14
RIGHT HEAD LIGHT		TERMINAL POSTS		FUSES 10 AMPERES
					NEGATIVE
						STORAGE BATTERY
	GENERATOR	MAGNETO				POSITIVE
						SWITCH
		CYLINDERS		BATT -LIGHTING SWITCH	No. 14
				No. 14BATT +		TONNEAU LIGHT
		GROUND	No. 10	GROUND FUSE
				MAGNETO SWITCH
		No. 18 DUPLEX		No. 14
				DASH & EXTENSION LIGHT
				No. 10
				AMMETER	No. 0
				HORN BUTTON		REAR LIGHT
HEAD LIGHT		MOTOR	STARTING SWITCH
				HORN
			25⁄8 LOOM

Fig. 89. Wiring Diagram—Jeffrey-Chesterfield Six

As a battery becomes charged its voltage increases reducing the difference in pressure between the generator and battery and decreasing the charging current to the battery.