Tune-Up

1929 Model 60 Specifications

BATTERY:-- U.S.L, Type S-CVX-5X6, 6 volt. The negative (-) terminal is grounded. Starting capacity (20 minute rate) is 96 amperes for 20 minutes. Lighting capacity (5 ampere rate) is 5 amperes for 16.8 hours Battery is mounted under the front floor boards on the right frame member and is grounded to the right clutch shaft support.

IGNITION:-- Coil Model IG-4066. Coil is mounted on the generator at the right of the engine. Ignition current is 1.5-2 amperes at 6 volts with engine running and 4.5-5 amperes at 6 volts with engine stopped.

Distributor Model IGB-4006-B. Breaker contacts separate .020-.025 inch. Set contact gap by loosening the lock nut on the stationary contact mounting stud and turning up the stud until the correct gap is secured with the breaker arm on the lobe of the cam. Resurface contacts whenever necessary with a fine flat contact file or on a medium hard oilstone. Breaker arm spring tension is 16-20 ounces. Distributor is semi-automatic Maximum manual advance is 25 degrees (engine). Automatic advance begins at 600 R.P34. of engine. Maximum automatic advance is 22 degrees at 2400 R.P.M.

Mounting:-- Distributor is mounted at right of engine on rear of the generator. To remove the distributor, disconnect the primary lead and manual advance rod and remove the distributor head with cables intact. Then take out the hold-down screw in the advance arm and lift the distributor from place.

Oiling:-- Put 4 or 5 drops of light engine oil in the oiler on the side - of the distributor every two weeks or each- 500 miles.

Timing:-- Three types of cylinder heads have been used on the Model 60. These heads are marked "15LA-606"--18 1/2%, "15LA-608--19%", and "14LA-617--20.9 %". The marks will be found on the top of the cylinder head at the rear of the engine. On engines equipped with cylinder head 15LA-606 or 15LA-608 breaker contacts begin to separate when the piston entering power stroke reaches a position 8 1/2 degrees or 21/2 teeth on the flywheel before top dead center with the spark control fully advanced. On engines equipped with the 14LA-617 head, breaker contacts separate when the piston entering power stroke reaches a position 16 degrees 4 minutes or 5 teeth on the flywheel before top dead center with the spark control fully advanced. To set timing, crank engine over until piston No. 1 enters compression stroke (the up stroke with both valves closed). Fully advance spark control lever. Carefully note type of cylinder head on engine and continue to crank engine until a point,21/2 teeth on the flywheel (on cars with 15LA-606 or 15LA-608 heads) or 5 teeth (on cars with 14LA-617 head) before the top dead center mark is directly opposite the indicator line in the engine block directly above the crankshaft. Then loosen advance arm clamp screw and rotate distributor until contacts begin to open. Tighten the clamp screw and connect the segment opposite the rotor to the spark plug In cylinder No. 1. Connect the remaining spark plugs In order 5-3-6-2-4 clockwise around the distributor head.

Firing Order:-- The firing order is 1-5-3-6-2-4.

Spark Plug:-- Spark plugs are 7/a-18 B.A.B. Standard. Gaps are .025 inch.

VALVE TIMING:-- Specifications:-Head diameter, 1% inches. Stem diameter, .371 Inch. Stem length, 51/4 inches. Valve lift,-,.5/16.inch. Spring pressure, 85 pounds (valve open-spring length, 2 inches). Tappet clearance, .006 inch (hot). Valve stem guides are removable. Valves with oversize stems are not 
made.

VALVE TIMING

The following table contains complete valve timing specifications for Durant automobiles. The correct timing procedure will be found in the paragraphs under the car model heading.

VALVE TIMING TABLE

Durant all Models 1928-29.--To check the valve timing set the tappet clearance of No. 1 cylinder exhaust valve at .008". Crank the motor until No. I exhaust valve just closes. At this point, the flywheel mark EC-1 should appear at the indicator of the peek hole in the flywheel housing. On models not equipped with an enclosed flywheel, indicator for valve timing is the centerline of the last cylinder. Durant Models 6-14 and 6-17 1930.--To check the valve timing use the procedure given above for previous models with the exception that the tappet clearance for checking timing should be set at .012" for Model 6-14 and .010" for Model 6-17 (see valve tinting table for timing data).

Durant Model 407 1930.--To cheek the valve timing set the tappet clearance of the intake valve for No. 1 cylinder at .012". Crank the motor until No. 1 intake valve just starts to open. At this point, the flywheel mark indicating top dead center of pistons 1 and 4 should register with the pointer of the peek hole in the flywheel housing.

Information Donated by Carol Rush

Durant 1928-30 Motor Tune-Up

The most important operations in a Durant motor tune-up are ignition timing, spark plug gap setting and distributor point adjustment. If difficulty is experienced at idling speeds on cars equipped with Tillotson carburetors, check for defective by-pass tube (see Auxiliary By-pass Tube in section Following Tune-Up Operations). The carburetor is the last unit that should be checked, all other adjustments such as timing, spark plugs and contact point settings should be made before changing or adjusting the carburetor.

Tune-Up Operations

1. Clean and adjust distributor and spark plug points.
2. Check timing chain for slack; adjust if necessary.
Note: Care should be exercised not to get the timing chain too tight. Adjust the chain to a point just below a hum. If timing chain is loose, proper results cannot be obtained when timing the motor.
3. Check the ignition timing; adjust if necessary.
4. Adjust the valve tappets and free up valves.
5. Clean gas line strainers and screens. Also check gas lines for loose fittings.
6. Check fan and generator belts. Adjust if necessary,
7. Tighten water pump nut. This operation is only necessary when packing gland is leaking.
8. Adjust carburetor, clean if necessary.
9. Road test car.
Note: The ignition should never be advanced beyond a point where a spark knock occurs except under full load conditions.

Ragged Idle

Ignition Timing.--A condition of poor idle may be caused by the ignition timing being advanced too far. The symptoms are similar to those
caused by a too rich carburetor mixture and are especially noticeable at idling speed.
Spark Plug Gap.--A poor idling condition on Durant motors may be caused by spark plug gaps being set too far apart. The recommended
setting is .027" for all models of Durant.
Distributor Points.--When tuning a motor it is important that the distributor points be thoroughly cleaned and squared up: Dirty distributor contacts may create a condition of motor performance very similar to a rich carburetor mixture condition. The motor will run poorly at low speed and cut out at high speed.
High Vacuum in Manifold.--A poor idling condition especially noticeable on deceleration, may be caused by a high vacuum in tile manifold over the throttle on Durant cars equipped with Steamberg Model U carburetors. The car may idle properly on the service floor but when the motor is accelerated to full open throttle and then decelerated suddenly to full closed throttle, a tendency to load and Roll wall be noticed. In extreme cases the motor may even die on deceleration. The ear owner generally complains that the motor dies in traffic. To correct this trouble, drill a No. 52 hole through the throttle valve butterfly about $/16" in toward the center of the carburetor throat opposite the idle discharge opening.
Caution: The throttle valve should never be drilled unless the trouble cannot be corrected by reducing the size o£ the main metering jet or Economizer by-pass.

Auxiliary By-Pass Tube Defective

If trouble is experienced in obtaining an idling adjustment on Tillotson carburetors used on Durant cars, the trouble may be caused by a defective or split auxiliary by-pass sleeve (A) Fig. 9. A poor idling condition may also be caused by dirt collecting in the bottom of the auxiliary by-pass or idling tube (B). If the trouble should be caused by dirt in the bottom of the idling tube, see that the filter screen around the bottom of the tube is thoroughly
cleaned.

In the operation of forming the auxiliary by-pass sleeve (A) Fig. 1 the end of the sleeve may crystallize and split or fold under when the. By-pass tube is seated. Invariably a leak at this point will cause the air vent chamber surrounding the tube proper to flood and proper air bleed is prevented. Showing method of flaring by-pass tubes used on Tillotson carburetors. In the left hand view (A) two by-pass tubes are shown, that were damaged in flaring or during the operation of installation. When the by-pass tubes are damaged in this manner carburetor operation will be affected. Durant 1928-30

Extreme care should be exercised in the fitting of by-pass tube. By fitting we mean the clearance between the hole in the upper half of the carburetor body casting and the outside diameter of the by-pass tube. When air is allowed to leak at the point immediately on top of the tube the mixture is thinned and the low speed adjustment is rendered inoperative in proportion to the amount of air, which passes around the tube. By using a small tapered punch having a point angle of 30° those tubes found to be undersize can be flared as desired.

Lack of Power

Improper adjustment of the Metering or Economizer Needle--Lack of power at high speeds on all models of Durant’s equipped with Tillotson SP and V types of carburetors may be caused by improper adjustment of the economizer or metering needle. The nut which is pinned to the lift needle can be adjusted when necessary. This adjustment should allow a lift and fall of approximately 3/32". The clearance between the bottom of the nut and the contact point of the lever fork should be about .040". In replacing cotter pins be sure that the ends of the pins after being bent do not ride or touch the body casting thus interfering with tile free action of the lift and fall of the needle.

Low Gasoline Mileage

Auxiliary Needle Valve Held Open-On cars equipped with Stromberg Model U carburetors, low gasoline mileage may be caused by the auxiliary control lever cam riding the auxiliary control lever thus holding the auxiliary needle valve open. To correct, set the auxiliary control lever cam so that there is approximately 1/16" clearance between the cam and the auxiliary control lever. Also check to see that the auxiliary control lever. Fulcrum screw does not bind and that the lever works freely.

Gasoline Leaks

Loose Main Nozzle (Tillotson Carburetors)-A gasoline leak, which may be confused with a leaky float valve ma}, develop on all models of Tillotson used as equipment on Durant cars. The trouble is generally indicated by a slow dripping of gasoline or a wet carburetor body. The main nozzle is screwed into its passage against a gasket. The trouble may be caused by the jet loosening up and working down on the thread away from the gasket thus causing a leak at the gasket
between the shoulder and the carburetor body at the top of the nozzle. To correct, remove the adjusting screw assembly at the bottom of the carburetor and screw the jet up tightly against the gasket. Care should be exercised not to confuse this condition of trouble with a leak that is caused by incorrect float level adjustment. If the gasoline level in the float bowl is too high, gasoline will have a tendency to seep over the top of the main nozzle thus causing a leaky condition, which may be indicated by a slow dripping of gasoline or a wet carburetor body. If the trouble is caused by the wrong gasoline level, correct by resetting the float to the correct height. (See float level adjustment under Carburetor Specifications).

Leaky Channel Plugs

A gasoline leak which may be confused with a leaky float valve may develop on all models of Tillotson used on Durant models. The trouble is generally indicated by a slow dripping of gasoline or a wet carburetor body. To correct this trouble, remove the carburetor air horn and tighten up the channel plugs with a screwdriver.

Information Donated by Carol Rush

Ignition Timing

Durant, all Models 1928-29 (semi-automatic spark advance)

To time the spark to the motor, crank the engine until No. I piston is approaching T.D.C. of the compression stroke and the "IGN" mark on the flywheel mark D.C, 1-4 or 1-6 registers with the indicator in the flywheel housing. On models not equipped with au enclosed flywheel, the indication for piston position is the center line of the casting of No. 4 or No. 6 cylinder with the spark control in the full advance position.

The distributor should be set so that the points are fully open and the rubbing block of the breaker arm is on the leading edge of the cam peak. When in this position the rotor should be under the terminal leading to No. 1 spark plug. Due to the slight variation in the action of the automatic advance mechanism, it may vary from the Ignition Timing Table.

The following table contains complete ignition timing specifications for Durant automobiles. Complete details for tuning procedure will be found in this section under the car model heading.

IGNITION TIMING TABLE

If it be found necessary to alter the ignition timing from that described above. On some distributors best performance is obtained when the points are set to just break contact while others require the rubbing block of the arm to be set at the peak of the cam. Road testing the car will determine the setting best suited to the motor. (See ignition-timing table).

Durant, Model 6-14, 6-17 and 407 1930--To time the spark to the motor, crank the engine until No. I piston is approaching T.D.C. of the compression stroke and the "IGN' mark on the flywheel registers with the indicator of the peephole in the flywheel housing with the spark control in the full advanced position. The distributor should be set so that the points just break contact with the rotor under the terminal leading to No. 1 spark plug. (See ignition-timing table).

Information Donated by Carol Rush

Spark Plug Replacement Chart

US Manufactured Durant Automobiles

Plugs may be purchased over the Internet at: http://www.sparkplugs.com