The modern diesel engine is a reliable machine, but it must be given proper care and attention, both when running and when idle.
These instructions cover the general features of operation and maintenance of Model 158-6 Winton Diesel engine; describe the procedure under all ordinary conditions, and if carefully followed will result in satisfactory and reliable operation with a minimum cost of maintenance.
Many operators feel that they can improve their machines by tinkering or changing the finished product as it leaves the shop. To such operators we say: Our practices, as outlined in this book, have proved highly successful in many years of service. We know that they give the best results, and we advise that tinkering and changing be avoided, no matter how appealing some other method may be theoretically.
In ordering parts, be sure to give engine number, model, horsepower, and R.P.M.
Instructions for Care and Operation of WINTON DIESEL ENGINE MODEL 158 - 6
ALL OF THE FOLLOWING INSTRUCTIONS SHOULD BE FOLLOWED AT ALL TIMES BY THE MAN IN CHARGE. A LOG SHOULD BE KEPT, NOTING ALL THAT HAPPENS AND TIME OF STARTING AND STOPPING, IN ORDER TO FOLLOW THE SCHEDULED MAINTENANCE OUTLINED HEREIN.
Before shipment, engines are thoroughly tested and properly adjusted. They are shipped fully assembled, with oil and water drained out.
Before bolting engine coupling to coupling on driven member, check the shaft alignment. The coupling faces must be parallel. It is usually convenient to use a set of feelers and test at eight equally spaced points. Turn the shaft 180 º and test again in the same way. If the faces are parallel, the feelers will be gripped the same amount at all points.
Run the exhaust to the atmosphere as direct as possible. Do not use sharp bends or piping smaller than the exhaust opening on the engine, as these cause back pressure and reduce the power of the engine, or may possibly burn out the valves.
It is suggested that the exhaust be led to a silencer installed outside the engine room, locating the silencer far enough away from the engine to prevent burning of valves.
Cooling water intake supply line should be located low enough to keep system full at all times.
Cooling water discharge piping leading from the engine should be as large as the outlet on engine, and not unduly restricted by bends and fittings. The discharge should lead up from the highest point on the engine and discharge overboard, thus avoiding any chance of air pockets.
The lubricating oil cooler should be by-passed to maintain proper temperature on lubricating oil.
Fuel oil is delivered to fuel pump on engine from fuel service tank under a pressure of approximately 5 to 6 pounds per square inch. This pressure is maintained by fuel service tank elevated to a height of 10 feet above the fuel pump on engine. The top of this tank is fitted with a return line from which the overflow is led to the storage tanks with a vent above overflow connection.
The fuel oil service tank should be fitted with the drain at bottom. The opening in service tank for fuel pump suction should be several inches above the bottom of tank.
Starting air tank should be installed with a drain pointed down to keep free of water and oil, and should be fitted with a safety valve set to relieve at 400 pounds pressure.
The line from each air tank should be fitted with a stop valve close to the tank, and a gauge for indicating pressure.
In order to facilitate starting of the auxiliary compressor, a bleed valve, opening to the atmosphere, should be provided in the line near compressor. This valve should be opened when starting compressor and valve at tank closed. When compressor attains speed, close bleed valve and open tank valve. A safety valve must be provided between compressor discharge and stop valve.
Pipe, valves and fittings suitable for 400 pounds per square inch air pressure should be used for starting air line.
PREPARING THE ENGINE FOR OPERATION
When preparing the engine for operation, the following inspection should be made and precautions observed:
The engine should be kept clean at all times.
Open lights must not be used for inspection purposes and the engineer in charge should see that printed instructions to this effect are placed in a conspicuous place in the engine room.
Inspections of engine should be made in the manner specified in these instructions. These inspections should be made at definite periods; neglecting to make them may force a shut-down.
The temperature of engine room should not, if possible, be allowed to go below 40 º Fahrenheit. If this temperature cannot be maintained, the cooling water should be drained from all water jackets and lines when engine is stopped.
The lubricating oil line should be cleared of all scale, chips, and foreign matter by blowing through with air before being connected to the engine. All burrs should be removed from ends of pipe.
When starting a new engine or after extended shut down, suitable means should be provided for forcing lubricating oil through all bearings. All bearings should be inspected to see that lubricating oil lines are clear and that bearings are getting oil.
All special tools and spare parts should be kept in the best of condition, and available for immediate use.
Make sure that all engine holding-down bolts are tight. Check all water, lubricating oil, fuel oil, air and exhaust connections.
The cooling water pumps on the engine draw water from the sea through the lubricating oil cooler.
There are two lubricating oil pumps on the engine. One draws oil from sump in lower crankcase of engine and delivers it through the oil cooler to lubricating oil filter. The other pump draws the filtered oil from filter and delivers it under pressure to lubricating oil manifold on engine.
A bypass is fitted on the discharge of the latter pump, in order to regulate the pressure of lubricating oil in manifold by by-passing the discharge to the suction.
The lubricating system should be completely filled, including the double filter tank and cooler. This will take about 50 gallons of oil.
Oil all bearings, pins, valves stems, etc., arranged for hand oiling. The valves stems should be lubricated with a mixture of half kerosene and half engine oil to prevent sticking. On engines with dual valves, the valve plunger tee pieces should be oiled by hand.
Open all suction lines to pumps.
Open all discharge lines.
After engine has been started, regulate cooling water, so as to maintain a discharge temperature of 90 degrees F. to 110 degrees F.
Fill service tank by use of the transfer pump
Fuel pressure gauge on gauge board should indicate five pounds pressure.
Bleed air from fuel lines by opening bleed valves on pump and manifold. Close each bleed valve as soon as fuel oil flows through. If fuel oil is thick, the operation may be assisted by the use of hand pump in fuel pump block.
Pump up starting air to a pressure of 350 to 400 pounds.
Open cylinder cocks and turn engine over several times without fuel turned on. Close cocks. (If this precaution is not followed, pre-ignition may occur, with probable damage to engine.)
The actual starting operation is controlled by a single air valve which automatically admits starting air to each cylinder through check valves in cylinder heads. When ready to start, make sure the fuel shut-off valves for each cylinder are all open. Place the wedge hand lever in half-speed position, pump up fuel pressure in manifold to 2,000 pounds pressure with hand pump. Open the air throttle until engine has made eight or ten revolutions and then shut off the air. The engine will start to fire immediately if all the adjustments have been properly made.
There are only two causes for an engine failing to start:
Fuel is not reaching the cylinder.
Compression is too low.
The first of these may be caused by air in the fuel oil lines; fuel shut-off valves may be closed; or the fuel spray valve may be plugged by dirt which has gotten into the piping during installation.
Low compression in a new engine is usually caused by not having the fuel or main valves down tightly on their gaskets; or the compression relief valves may not be completely closed. If the main valves do not work freely in their guides, they will also cause loss of compression. As soon as the engine has started, make sure there is at least 15 pounds pressure on the lubricating oil gauge, and the cooling water is circulating properly. Pump up the air in tanks again, making it a habit always to have enough air in the tanks to start at any time. If the air tanks and fittings are properly installed, the air can be held indefinitely
Regulate the fuel pressure until the engine runs smoothly. You will find that about 5,000 to 7,000 pounds pressure gives the best results for full load.
To stop engine, withdraw wedges from under injection rocker levers by means of hand lever on end of wedge shaft. Hold out until engine has stopped. After engine is stopped, be sure to shut off fuel feed to pump.
The engine should be cooled before stopping to 90 º – 100 º F. This temperature should not be permitted to increase after engine stops.
The engine should run at reduced speed after starting, and allowed to warm up gradually, permitting oil to thin out and flow freely, giving the metal time to expand slowly and evenly
The by-pass relief valve on lubricating oil pump discharge line should be adjusted so as to maintain a pressure on lubricating oil gauge of 15 - 30 pounds, depending on engine speed and load.
Test cooling water circulation and free system of air by means of try-cocks on system.
Water circulates properly.
Lubricating oil has sufficient pressure ---- 15 – 30 pounds.
Combustion takes place equally in all cylinders without smoking.
None of the starting air valves are leaking. (Determined by feeling the pipe from each valves.)
Fuel pump is working properly and fuel lines are tight.
Engine is running without any strange sound.
Fuel oil filters should be cleaned as often as may be found necessary, depending upon the amount of dirt and sludge in the oil.
At regular intervals the exhaust gases should be examined and if thermometers or pyrometers are available, the temperatures should be recorded. Any abnormal rise in temperature of a cylinder, compared with others, should be immediately investigated.
Do not overload engine. If all proper adjustments have been made, smoky exhaust indicates that engine is being overloaded
Do not run without a full supply of lubricating oil in the system
Do not use a poor grade of lubricating oil
Be sure that oil gauge indicates the proper pressures
ENGINE STARTS SATISFACTORILY BUT STOPS AFTER A FEW SECONDS
This condition may be caused by one or more of the following:
(a) Fuel supply may have run out.
(b) Valves in fuel line may be closed.
(c) Service tank may have been left undrained so long that the water level will have risen to the fuel pump suction opening, thereby causing combustion to fail.
(d) Fuel oil strainer may be filled with dirt or water.
IRREGULARITIES IN RUNNING
Knocks Within the Engine
After the engine has been started from the cold condition, the first few combustion strokes will be rather noisy, as the cold cylinders do not allow proper combustion to take place at once. As soon as the engine is warmed, however, these knocks disappear. As these knocks have a very metallic sound, they might mislead one to think that they are caused by a loose bearing, but by carefully studying the nature and time of occurrence of the knock, it can be easily determined that they are connected with each combustion stroke. Should the knocking continue and is found that it is not due to a loose bearing, it should be investigated. If an indicator is available, a set of pull cards should be taken from each cylinder to determine the difficulty.
Injection Valves Stem Sticks
In case the injection valve stem sticks or leaks, fuel will be admitted into cylinder other than at the time of injection. Before the engine starts knocking or the safety valve opens, this trouble will be shown by the exhaust becoming a heavy black. By quickly turning the spindle when off seat and applying a few drops of lubricant, this trouble may be overcome. Unless this eliminates the trouble at once, the engine should be stopped, as there will be danger of a burned valve seat or possibly an explosion. When the engine appears to be running smoothly, and a safety valve suddenly commences to blow off, the engine should be immediately stopped in order to save the injection valve.
If the injection valve cam clearance is set to give good operation with one kind of fuel and then a heavier or lighter fuel is used, usually a knock will develop, especially with the use of the lighter fuel. This can be adjusted by altering the injection valve cam clearance to suit the particular fuel. With the lighter fuel, it might be necessary to retard the time of injection. Whether this is necessary can be determined by taking a set of indicator pull cards from the cylinders.
All operators of internal combustion engines should clearly understand that the worst condition that can exist is that of a smoky exhaust. When the engine smokes, the fuel consumption increases rapidly, and the heat developed per cycle is much greater, without any increase in the power developed. This causes greater strain on the cylinder walls and head and is very detrimental to the exhaust valves and valve seat. Unburned carbon particles are forced between the rings and cylinder liner, increasing the friction and causing excessive wear. It can be clearly seen that the engine should be run at all times with a clear exhaust. The engine should never be allowed to carry a load so great that a clear exhaust cannot be obtained with normal operating conditions. Overloading is not always the cause of smoky exhaust as some of the cylinders or all of them may be smoking without overloading the engine.
The following are some reasons for the engine smoking:
All Cylinders Smoke.
The engine is overloaded.
Bearings or other moving parts are out of adjustment, thereby decreasing the mechanical efficiency so as to overload the engine.
When the engine is driving a generator, the electrical instruments may be out of adjustment and under-rating the developed power, so that when normal load is indicated, the engine is operating at an overload.
When the grade of fuel oil is changed and proper adjustments are not made to suit the new fuel, the engine will smoke.
Too much clearance between injection valves cam and its roller.
Too late combustion.
In all of the above cases a set of indicator pull cards should be taken to determine the exact nature of the trouble.
One Or More Cylinders Smoke.
Injection Valve Leaking. When the exhaust is light blue in color, some injection valves may be leaking. This leakage may be due to dirt under the valve. Turning the spindle often relieves this condition.
If a knock occurs, it is probably due to a sticking valves. A condition of this kind should be attended to immediately, to prevent damage to valves and excessive strain on cylinder and head.
Too Much Clearance Between Injection Valve And Its Roller. This is usually due to careless adjustment, although wear may have produced this condition from prolonged operation due to roller plug binding and wearing flat in one place.
The Engine Loses Its Speed
Leaky fuel pump valve. If fuel pumps and their valves are leaking, pressure drops on gauge, and the engine speed will be reduced without any black smoke at the exhaust.
Hot Bearings. A few warm or hot bearings will overload the engine so the speed will be reduced and the engine will smoke.
Injection Valve Burned Off
This may be due to the following:
Valve stem packing so dry that the valves sticks.
Exhaust Valve Sticks
The usual cause of this trouble is the stem becoming coated with carbon, particularly when the engine has been operated with a smoky exhaust, or due to excessive lubrication of valve stem. The best treatment for a sticking valve is to give it a few drops of half kerosene and half engine oil occasionally and when this has washed out the dirt a few drops of lubricating oil should be applied.
When the exhaust valves have been run longer than the specified time without regrinding or replacing, the valve will start to leak and will soon become burned so that will be necessary to replace not only the valve but also the valve seat.
If a valve stem becomes so dry as to make a squeaky or groaning sound and above kerosene and oil treatment does not remedy the trouble, the engine should be stopped immediately and the valve changed.
The most important factor in efficient operation is proper combustion. Although the engine may run with poor combustion and not give any noticeable trouble, its economy is seriously affected and wear on the cylinder liners and piston rings is excessive.
Proper burning of fuel in cylinders is dependent on several factors, and it is the purpose of this chapter to enumerate these, and so far as possible to furnish the operator with information which will enable him to properly control the combustion in the cylinders.
The fuel to be used is very important. There is a prevalent idea that a Diesel engine can burn any fuel that is in a liquid state, and that it is only necessary to heat a heavy oil until it flows freely to make it suitable for Diesel operation. This, however, is only partially true, as it is not only the viscosity and specific gravity of an oil which decides its suitability, but also its chemical composition. It is very difficult to say just which oils are suitable for Diesel engines.
The total cost of operation depends not only on the cost of fuel but also on the upkeep and other operating costs. A heavy oil must be heated to enable it to flow freely and to allow proper atomization. The cost for installing a system for heating the fuel must be considered. Combustion of heavy oil always requires more attention than that of a light oil, and too, there is the additional trouble of heating the oil, which is undesirable from the operator’s point of view. Most heavy oils contains sand and sulphur. These cause excessive wear on the cylinder liners and pistons and pitting of valves.
Following are the requirements for a satisfactory fuel oil for Diesel engines:
Baume gravity, 60/60 – not heavier than 26 º nor lighter than 34 º.
Heat value – not less than 18,500 BTU per pound.
Residue – not more than 10 %. Residue is that portion of the oil remaining in the cup after being subjected to a temperature of 300º C. (527 degrees F.) for 120 hours.
Flash point – Not less than 150º F. (Pensky – Martin closed cup).
Sulphur – Not more than 1.0 %.
Water – Not more than 0.5 %.
Ash – Not more than 0.5%.
A high sulphur content does not affect combustion, but the sulphur dioxide formed in combustion combines with the water or steam present to form sulphuric acid, which pits the valves, liners and pistons.
GENERAL DESCRIPTION AND MAINTENANCE OF ENGINE PARTS
The general construction of engine is shown by the cuts in the back of this book.
Following is a description of the more important parts, together with information concerning proper maintenance.
One-piece semi-steel casting with stiffening ribs to insure rigidity. Large handhole plates on both sides afford ready access to main bearings, crank pins, and camshaft bearings. A gear case on the rear end encloses the camshaft gear train.
Semi-steel casting. Carries crankshaft. Main bearings are cast integral with the base. Seatings are accurately machine to receive removable babbitt-lined shells. Bed-plate is heavily ribbed and held down by steel bolts.
Crankshaft and main bearings
The crankshaft is made of high carbon steel and is subjected to rigid inspection and classified by the American Bureau of Shipping, or Lloyd’s. The entire shaft is machined and is drilled from main bearings through cheeks and pins for lubrication. All bearings and pins are ground. Bearings are lined with best grade babbitt, scraped to fit.
The main bearings are held in position by heavy cast iron bearing caps. The caps are numbered for location. Castle nuts with cotter pins hold caps on studs which are securely screwed in the crankcase. Movement of shells is prevented by dowels. Shims are provided between main bearing caps and crankcase for adjustment of bearings.
The life of a crankshaft is practically dependent upon main and connecting rod bearings and their maintenance.
With the forced feed system, bearings receive the best possible lubrication, and with the rugged construction of frame and method of securing bearings, their alignment is assured from a design standpoint. However, misalignment may occur if one bearing should wear more than another. For this reason main bearings should be checked once each year if engine has been in constant operation.
To fit a new bearing shell, remove bearing and top half of shell. Under ordinary conditions, the bottom shell can be rolled out by rotating the crankshaft. If it should stick to the crankcase, tap it with a piece of wood in the direction of rotation of the shaft. The new shell can be worked into the crankcase by rotating the crankshaft.
The main bearing clearance is .001" per inch diameter. End clearance is 3/64" at each end.
Care should be taken when tightening the top cap that the bolts are drawn evenly and not sledged too hard.
Each shell has one annular oil groove to carry oil for crankpin and piston pin, and a wedge-like relief at the split line were shells meet. The metal between this relief and the round of the bearing should be scraped smooth and tangential without sharp corners. By doing this the best lubrication is obtained, as the oil wedges in between the shaft and babbitt, forming a film of oil on which the shaft floats.
I section drop forgings, "T" construction, high carbon steel with detachable journal boxes. Crankpin boxes are of cast manganese bronze, lined with high grade babbitt, scraped to fit, and bolted to connecting rods with four steel bolts. The short groove in the center of the bearing merely acts as a passage for the oil coming from the crank and going to piston pin through tube on connecting rod.
Connecting rod should be inspected regularly to ascertain whether the piston pin oiling tube is securely fastened in place. This tube is used only in engines above 10" diameter bore.
Crankpin boxes must be kept accurately fitted. They can be checked for clearance by loosening connecting rod bolts, allowing bottom of box to drop down about one inch, and then inserting a piece of 1/16" soft lead wire cross-wise between bearing and shaft. Then tighten up box and again drop the bottom half and remove wire. Check for clearance.
In fitting a new box, be sure that all high spots in the box have been scraped off and that the running clearance is .001" per inch diameter.
When scraping bearings, make the radius at end of bearing larger than the fillet on crank, so that end movement will be taken up by bearing flanges. A 3/64" relief in the babbitt at end of bearing caps is desirable to prevent sharp edges of babbitt. The curve should be tangential so that the oil will wedge itself in and form a supporting film as described for main bearings.
In tightening up crankpin bolts, do not sledge them up unnecessarily hard. The bolts not only hold the two halves of the boxes together, but withstand the reciprocating forces when engine is running. The operator should make sure that the nuts are locked tight and that the cotter pins are in place, also that no rags or dirt has been left in oil passages.
Pistons are of the trunk type and serve as a piston and cross head. They are made of aluminum alloy. A long skirt insures low guide pressure and minimum wear.
Each piston has five (5) cast iron piston rings. The upper four (4) are the compression rings and the bottom rings serves as an oil scraper. A groove is cut in the piston below the scraper ring. Through this groove drain holes are drilled to drain excess oil from cylinder walls.
Piston rings are fitted with .002" per inch diameter and clearance on top ring to .001" and clearance on bottom ring. Scraper ring should be rounded on top.
If engine has been in continuous service, pistons should be pulled at least once each year for overhauling, which can be done at the same time that bearings are attended to.
In filing the rings, the bearing surfaces should not be touched more than necessary. The top rings wear the most because of the higher temperatures to which they are subjected. When this wear amounts to less than .003" per inch of diameter, new rings should be installed. When new rings are put in, be sure that they have proper clearance. When replacing the piston in cylinder, be sure to use the fixture furnished to guide the rings properly.
Just after a piston has been drawn, it will nearly always show water around the lower rings. This condition is practically always due to combustion of fuel and not to water leaks. The oil contains hydrogen which during combustion combines with the oxygen in the air to form water. At the high temperatures prevailing in the combustion space, the water is formed as steam, the greater part of which leaves the cylinder with the exhaust gases. However, a small portion will work its way with some of the cylinder gases past the rings and there, where the temperature is lower, condense into water.
The condition of piston and liner gives a good indication of the quality and quantity of lubricating oil used. If rings and liner have a bright surface and rings are free, it is an indication of good oil and sufficient quantity. If the surfaces have a dull gray appearance and are more or less stuck, it indicates poor grade of oil, although the quantity may be sufficient. Too much lubricating oil, even if of good quality, may cause sticking rings and too little oil makes the rings and liner wear excessively.
It must be remembered that even with the correct amount of the best lubricating oil, the piston may be in bad shape with sticking rings if combustion is not correct and engine has been smoking.
If the pistons score for any reason, the engine should be stopped as quickly as possible. If conditions make it necessary to start the engine again as quickly as possible, it may be done after engine has been allowed to cool down. In such case, the full load should not be put on the engine unless it is absolutely necessary. However, do not run long under these conditions, but at the first possible opportunity remove the piston and overhaul both piston and liner.
Wrist Pins And Bearings
Wrist pins are of chrome nickel steel, hollow bored and fitted with oil tubes. They are hardened and ground and securely clamped in connecting rod, (which is split in the upper end) by a clamping bolt, that partially passes through the pin.
Wristpin bearing, as in any other reciprocating engine, requires the most attention. The reasons for this are: First, the relatively high bearing pressures, and second, the difficulty of lubrication on account of the pendulum motion. The bearing has been made as large as possible without impairing the strength of the piston, and bearing pressure is comparatively low. Lubrication is taking care of by oil passing up through the tube on connecting rod. The oil passes to a reservoir formed by the oil tube in the hollow wristpin. An oil hole in each end of the pin allows oil to flow from the reservoir to the inside of the pin bearing. The oil is assisted to reach the bearings by a ball check valve installed in the oil line on the rod, which has a pumping action at each revolution of the engine. This check valve prevents all of the oil from leaving the tube and reservoir when engine is stopped.
Wrist pins are fitted with .001" per inch diameter clearance.
If properly lubricated, the wrist pin bearing should run for at least a year under hard continuous service without any attention.
Water box is a one-piece casting made of close grained charcoal iron and is flanged for bolting to top of crankcase. Into this casting are inserted the cylinder liners. The water box has ample space for cooling the cylinders under all conditions of operation, and is provided with cleaning holes. Bedplate, crankcase and water box are all held together by alloy steel bolts.
The frequency with which water space has to be cleaned largely depends upon the character of water used in cooling system.
Cylinder heads are made of chrome nickel iron; cast individually; readily detachable without removing either the intake or exhaust manifolds. The heads are thoroughly water jacketed, cooling water passing up from the water box through ferrules pressed therein. Each cylinder head carries seven valve cages – two for intake valves, two for exhaust valves, one each for injection valve, non-return starting air valve, and safety valve. The head also is equipped with an indicator opening and valve and a connection for pyrometer for exhaust gas temperature.
The cylinder head and the water box have male and female joints. A copper gasket is used to make the head tight. A gum rubber gasket is placed around each water bypass ferrule to prevent leakage of cooling water passing from water box to head.
At certain intervals, heads should be removed and inspected for cleanliness. If cooling water has a tendency to scale, or if it is muddy, this inspection should be made once every six months. The condition of one head will indicate whether all heads should be removed for cleaning. Equal parts of hydrochloric acid and water will be found to be a very satisfactory mixture for this purpose. The mixture should remain in the head for about 16 hours and after draining, head should be thoroughly washed out with water.
To remove a cylinder head, first remove the cooling water discharge manifold, then remove the rocker arms. Break the air and fuel line joints and remove the cylinder head stud nuts. Two tapped holes are provided in each head for eye bolts, for removing head. Do not pry or drive wedges between cylinder head and water box, as the finished surfaces can be easily damaged.
When replacing head, have both head and cylinder surfaces clean and dry. Put one gum rubber gasket on each water by-pass ferrule, then put on the copper cylinder head gasket and carefully lower the head into position. Do not use damaged gaskets, as compression, oil and water leaks will result.
When tightening cylinder head nuts, pull gently and evenly on all nuts, then tighten opposite nuts alternately until they have all been pulled up evenly and tightly.
Liners are made of close-grained special iron. They are machined all over and the working surface ground. Machining gives uniform thickness, resulting in maximum and even cooling of cylinders and pistons. The liners are sealed at top by cylinder head and gasket and at bottom by stuffing box. The stuffing box contains a rubber ring at the bottom which is backed up with several turns of tallowed flax packing.
Water box clean-out plates should be removed at the same time the cylinder heads are cleaned and the liners inspected and cleaned if scale has formed. When replacing a liner a new rubber water seal ring and flax packing should be used. The packing joint should be inspected frequently for leakage
Most of the wear in a liner occurs near the top. The rest of the liner wears very little and remains practically parallel. The life of a liner is dependent upon the load, and the grade of lubricating oil used. Liners can be re-bored to .015" over-size before it becomes necessary to install new ones.
Exhaust and intake valves are made of special steel.
The frequency with which exhaust valves have to be ground is governed by several conditions: number of hours of operation; load carried; kind of fuel used; temperature of cooling water.
Do not overload engine.
Do not use heavier than 26º Baume fuel oil.
Do not use fuel oil containing more than one percent sulphur.
Do not allow temperature of the discharged cooling water to go above 120º F.
If engine is operating at about full load constantly, and with good combustion, the exhaust valves should run to 1,000 hours without trouble. At the end of this period, they should be overhauled. The valves can be run longer than this but it is poor economy to do so. If a valves leaks, the hot gases will soon ruin it so that it cannot be re-machined and must be replaced with a new one.
If an exhaust valve becomes very badly burned, the corresponding cylinder will not operate at light loads, say 25%, and a popping noise will be heard in the exhaust.
The inlet valve should be overhauled every 3,000 hours under any conditions of load.
If inspection shows that valves require grinding, a light spring should be put under the valve head, so that valve will be held just free of the seat. Grinding paste should be applied evenly over the valve seat. Grinding should be done with a very light pressure to avoid scoring the seat. A course grinding compound can be used at first, but the grinding should be finished with a fine compound. Rotate the valve, changing the position frequently to prevent grooves from forming. The light spring under valve head will lift valve clear of the seat between rotations. Clean off the seat occasionally and renew the compound until a full seat shows. Wash all of the compound off of valve and seat after finishing grinding, using gasoline or kerosene. If valves are pitted badly, time can be saved by facing off the seats. If cage seats need dressing up, it should be done with a valve reseating tool.
After valves have been re-ground and replaced in cylinder heads, care should be taken to adjust to the proper clearance. See valve timing diagram.
The injection valve packing gland should be tightened only enough to make the valve stem tight, particular care being taken not to cause the valve to stick, due to tight packing.
The camshaft is made of high carbon steel and cams are secured to shaft by tapered pins, riveted at the ends. It is carried at top of operating side of engine in a supporting housing which carries the camshaft bearings. This housing is mounted on the intake manifold. Cams run in an oil bath. The shaft is driven by a set of spiral gears from a vertical shaft (sic), which in turn is driven by the crankshaft. All gears are lubricated under pressure from main oiling system.
There are for individual cams for each cylinder, one inlet, one injection, one exhaust and one air starter. Cams are made of molybdenum steel, dropped forged, hardened and ground.
Fuel Spray Valve
For construction see cut.
This valve is one of the most important parts of the engine, and should be given careful attention. Ordinarily it will give little trouble, if properly seated and packed. If valve is not seated evenly, it should be carefully ground again, using very fine compound. Care should be taken to get a bright seat with an even bearing all around. After grinding, it should be thoroughly washed with kerosene to remove all traces of the grinding material.
To remove fuel valve from engine, remove rocker arms; disconnect fuel line at manifold and loosen valve lever adjusting screw. Loosen the clamp nut holding the valve assembly in the cylinder head and slide the clamp clear of the valve body. The valve assembly can now be lifted out of cylinder head. Remove the lock nut holding the seat. For cleaning holes use small pin vise, and suitable wire. After cleaning, fill tip with kerosene and force it out the spray holes by pressing palm of hand over large hole in seat.
In tightening fuel valve packing nuts, be very careful not to tighten enough to stick the stems. If the packing still leaks after tightening, it must be renewed, using a good grade of 3/16" square braided hemp packing, impregnated with graphite, similar to Garlock No. 117.
After packing or cleaning the fuel valve, connect to fuel oil manifold, pump up pressure, and make sure that valve does not leak before replacing it in the engine. See that the spray holes are all open by tapping the lever lightly with hammer. When replacing the valve in cylinder head, reverse the operation for removal.
Reset the clearance of the fuel valve lifter to proper clearance before attempting to start the engine. To do so, place the throttle in full open positions; see that the roller is not on the nose of the cam.
The timing of the fuel valve is adjusted before the engine leaves the shop. This adjustment should not be changed except upon the advice of the factory engineer to meet the unusual operating conditions. If necessary to change the timing, first set the fuel clearance as explained. Pump up about 2,000 pounds on the gauge and roll the flywheel slowly till the gauge drops, having the fuel stop valve on manifold open on this cylinder only. The dropping of pressure on gauge indicates the opening of fuel valve, and should be checked with marking of flywheel.
For proper clearance and timing, see valve timing diagram. As soon as the gauge pressure starts to drop, shut off the fuel stop valves to prevent flooding of cylinder. Be sure that all cylinders have the same advance.
The clearance for both intake and exhaust valves is set up between top of valve stems and bottom of adjusting screws in valve plunger.
Safety Valve and Non-Return Starting Air Valve
Each cylinder is equipped with the safety valve and a non-return starting air valve.
The safety valve is in direct communication with the engine cylinder, the valve being held on its seat against the pressure in the cylinder by a heavy spring, the tension on which can be varied by screwing down or up on the spring retainer.
The starting valve is of the mushroom type, is in direct communication with the cylinder, and opens inward. The starting air pressure opens the valve; when the starting air lever is released the pressure in the cylinder returns the valve to its seat; the return of valve to its seat is assisted by a light spring under valve.
As these valves are in operation a comparatively short time, they do not require much attention. They should, however, be kept tight at all times; otherwise, the valves and seats will be ruined.
With engine running at full speed, the safety valve spring should be backed off until the valve starts to relieve, then the spring retainer should be screwed down one and one-half turns. As it is very difficult to manufacture springs with exactly the same characteristics, it may be necessary to screw down a little more on some springs that on others, but this can be determined from the action of the valve with normal operation of the engine. Care should be taken that the spring is not compressed too tight, with the coils touching each other, as this will destroy all spring action.
Valves should be inspected every 4,000 hours, or whenever it is suspected that they are not operating properly. At the inspection., these valves should be lightly ground to their seats unless they have been damaged, in which event they should be turned in a lathe and the seats reamed, or new valves installed.
Starting air tubes and fittings should be felt with the hand frequently during operation to test valves for leakage.
Air Starting System
The air starting system on engine consists of a throttle valve, air distributor valves for each cylinder, and the air starter check valves mounted on the cylinder heads.
The air distributor valves are mounted on the camshaft housing and are operated directly by cams on camshaft. Starting air is admitted to these valves from the starting air bottles by the hand throttle valve on front end of engine.
With the proper attention these valves will give good service indefinitely. See that proper clearance is maintained on roller plug adjustment.
Lubricating Oil Pump
For construction see cut.
Single-acting, plunger type, driven by cross-shaft, which, in turn, is driven from front end of crankshaft through bevel gears.
Pump should be inspected once every six months, valve assemblies removed, springs and discs cleaned and if worn excessively replaced by new ones.
The governor is of a flyball type and is set to shut off fuel supply to engine at 10 revolutions above rated speed.
It is very important that the governor be kept in the best of operating condition all of the time. All wear and slack in the operating mechanism should be taken up.
Rocker arms are steel castings or forgings. Each cylinder has three rocker arms, one for inlet, one for exhaust, and one for injection. Rocker arms for inlet and exhaust carry hardened steel rollers and pins at each end, and the one for injection carries a hardened steel adjusting screw on valve end. Each set of rocker arms is mounted on a ground steel shaft, which is carried by two stanchions mounted on cylinder head.
The rocker arm bearings are arranged for hand oiling, the oil being fed to the bronze bushings through a small oil hole in each arm. These bearings should be given a few drops of lubricating oil each hour.
The injection valve wedge control mechanism is mounted on the camshaft box. This mechanism consists of a roller plug and wedge at each cylinder for controlling the lift of the fuel valve, and, consequently, the amount of fuel delivered into the cylinder at each firing stroke. The roller plug guide carries a hardened steel roller plug and hardened steel roller and pin. The roller rides on the injection cam and the top of roller plug is flat pointed where it contacts with the hardened steel wedge which increases or decreases the duration and lift of injection valve, by means of rotating movement of wedge lever shaft which runs full length of engine.
The setting of the wedges and levers on the shaft should under no condition be tampered with as the wedges are all exactly alike and the slightest variation in the setting will affect the operation of the cylinder.
Fuel Pressure Pump
The type of fuel pressure pump use on this engine is shown in Fuel Pump Assembly diagram in back of book.
Packed Type Pump
This pump maintains the fuel oil pressure in manifold, and fuel injection valves.
It is a reciprocating type, crosshead construction, with built-in hand pump. The steel cylinders, hardened steel plungers, crossheads, crankshaft and connecting rods are fully enclosed in a cast iron housing. Long packing boxes are provided for the plungers, packed with special packing.
The valves are carried in a steel block which also carries the cylinders. The hand pump works through the same valves as one of the pump plungers. To pump fuel pressure with hand pump see that there is clearance between suction valves and cut-off operating lever, and that no injection valves are open in cylinder heads.
The suction and discharge valves and seats are of hardened steel. Discharge valves are directly above suction valves with approximately one-half inch clearance between the ends to prevent discharge valves being opened by lifting of suction valves. Suction valves are spring loaded and their operation is controlled by an eccentric operated lever which is actuated by the plunger crossheads. Fuel pressure is controlled by increasing or decreasing the duration of opening of the suction valve.
The cylinder plungers should be inspected often for leaks, and special notice taken of that portion of the plungers which works in the packing, to see that no abrasive material has lodged in the packing and scored the plungers. Keep packing sufficiently tight to prevent leakage but not so tight as to cause binding or squeaky noise when in operation.
No shims are provided between the connecting rod and cap but if the clearance becomes enough to cause noisy operation, the cap may be filed to obtain the proper running clearance. Care should be taken when filing to get surfaces smooth and square to insure proper reassembling.
Crosshead and plunger have a special designed self-aligning joint which prevents excessive side wear on plunger or in plunger cylinder. A retaining cap clamps plunger collar to crosshead and also acts as an oil deflector to prevent fuel oil passing by the crosshead and mixing with the lubricating oil. When making the plunger joint, see that about .002" clearance is obtained to allow plunger to float. The crossheads are lubricated by pressure from manifold drilled into the fuel pump housing.
Suction and discharge valves should be inspected at least once a year or oftener as may be required. Discharge valves require little attention except to insure good seating and free working at all times. The suction valve requires more attention than the discharge valves. The seat condition and free working of the valve adjustment of the cutoff, and leakage by lapped joint of the suction valve stem should be looked after. If leakage becomes excessive, the valve and body should be replaced. When the engine is stopped, be sure that the fuel shut-off valve in main supply line is closed.
When the eccentric is turned to the horizontal position and the plunger at top of stroke, there should be 3/32" clearance between bottom of the suction valve and operating lever adjusting screw. After the engine is running a little further adjustment may be necessary. Setting of this adjustment is done by means of turn-buckle on vertical rod to wedge shaft which increases or decreases the clearance between the cutoff lever adjusting screw and suction valve.
A safety valve is provided on the discharge side of the pump block and set to release at 8,000 pounds pressure. If this valve does not seat properly, the leakage will soon destroy the seat and it will then be necessary to replace the valve.
Packless Type Pump
This pump is fitted with hardened steel plungers running in removable steel cylinders. Cylinders and plungers are ground and lapped to fit. Plungers are returned by a spring. A port is used for admitting fuel into pump cylinder and a valve provided in the outlet. The amount of oil pumped is controlled by revolving the plungers; this control being connected to the governor or throttle. The discharge pump valves are vertical steel checks working on steel seats; valves and seats being removable. It will be necessary to grind the discharge valve from time to time depending on the quality of fuel oil used. The discharge pressure on the pump should not exceed 6000 pounds under any conditions. Pressure relief valve is fitted in the pump discharge. This valve is usually set at 7000 pounds pressure. With the engine idling, the pressure should be run between 1500 and 2000 pounds and at full load between 4000 and 5000 pounds.
The fuel is taken into the engine through a strainer into the suction manifold on the fuel pressure pump. It is then metered through the suction valves and forced into the main header, then to the injection valves. An accumulator bottle placed in the high-pressure line cushions the impulses of the pump. The high-pressure gauge line is taken from a valve, mounted on the accumulator. This valve is used for preventing the gauge hand from fluctuating. Air bleed valves on the end of the high-pressure manifold and fuel pump serve to remove the air from the fuel lines. Drain lines on each injection valve take the leakage from the valve to a manifold which drains back to a sump tank. The fuel pump leakage also drains into this manifold.
For construction see illustration.
Two-cylinder, double-acting, reciprocating type. Pump body is cast iron, bronze lined, and fitted with bronze plungers. Plungers are packed with canvas duck packing. Pump is driven by a cross shaft, which, in turn, is driven from front end of crankshaft.
Pump should be inspected once every six months, valve assemblies removed, springs and disks cleaned and if worn excessively replaced by new ones.
The cylinders, cylinder heads, exhaust manifold and the exhaust valve cages are cooled by the circulating water system. The cooling water from supply passes through the lubricating oil cooler and then to the cylinder water box, from where it is forced through water passages in the exhaust manifold and cylinder heads; it is then discharged from the heads to the manifold running the length of engine above the cylinder heads.
The discharge should be taken from the highest point of engine, to prevent forming air pockets.
The cooling system will require little attention if the water jackets are kept free of sand and dirt. The water box plates should be removed frequently to ascertain the amount of dirt in the cooling spaces which will be an indication as to the necessity for cleaning all spaces cooled by the system.
For construction see cut.
Thrust bearing includes two pairs of thrust shoes (two shoes for ahead and two for astern thrust) individually adjustable fore-and-aft by jack screws, and a steady bearing, all mounted in an oil-tight housing with stuffing boxes at each end. There is one thrust collar, forged integral with the shaft.
Each shoe is supported at a single point, near the center of the back. At this point there is a hardened steel insert with a spherical surface, forming a pivot which allows slight tilting in any direction. This construction causes a wedge-shaped film of oil to enter between the bearing surfaces, resulting in complete separation and freedom from wear.
Lubrication is automatic, being accomplished merely by the rotation of the collar, which dips into the oil bath and carries oil up on its circumference to the top of the bearing. The oil scraper riding on the top of the collar distributes the oil, pouring large streams on the collar faces and thrust shoes. A branch stream, passing down through a special channel, lubricates the steady bearing and then drains back to the reservoir in the bottom of the housing.
A certain amount of end play is strictly necessary to permit the formation of oil films between the bearing surfaces, and to allow for expansion by heat.
A satisfactory rule for total end-play in propeller thrust bearings is to allow .001" per inch of collar diameter. If this end-play is much reduced, say by 50% or so, there will be a needless increase in friction and heating; very little is to be gained, however, by adding to the recommended amount of end-play.
The jack screws are provided for making the following adjustments: (1) locating the thrust collar in desired fore-and-aft position, (2) making both of the go-ahead or go-astern shoes so they are equally against the collar, and (3) providing the proper end-play.
Adjustments are made as follows: Remove the upper half of the housing (or remove the inspection plugs provided in the larger bearings), move the shaft to the desired fore-and-aft position, and turn the go-ahead jack screws so that both the go-ahead shoes are equally against the collar. Lock the screws in position. Then bring each go-astern to similarly into contact with the collar, allowing for end-play by inserting a "feeler" gauge of the proper thickness back of the shoe. Lock the screw, and remove the gauge.
Use same lubricating oil as that used for engine.
It is vitally important to maintain the oil at the prescribed level.
On each side of the housing, near the tapped hole for the oil gauge, the safe oil level range is indicated by "high" and "low" marks. With the shaft standing still, fill the housing with clean oil to the "high" mark. The running level will be a little lower because oil is carried up to supply the bearing surfaces. This apparent deficiency of oil need not be made up. The bearing is safe if the running level is above the "low" mark. Even if the oil gauge glass gets broken, sufficient oil for safe operation will remain in the housing, though, of course, a new glass should be put in as soon as possible.
See that the housing joints are oil-tight to prevent lowering of the level by leakage. The main horizontal joint is scraped metal-to-metal, and requires no gasket. The hand-hole cover joints are not scraped, and should be provided with paper gaskets. The stuffing boxes should have suitable soft packing and should be set up lightly, because the oil is not under pressure.
The air-vent holes usually provided in the upper half of the housing should be kept open so that no internal air pressure can be developed to cause loss of oil through the top of the oil gauge.
Lubricating Oil Filter
The filter consists of three bronze screen baskets, placed inside the filter tank
The filtered oil is drawn from the bottom of the filter. The bottom of filter is provided with a drain cock and on the side is located an oil gauge for indicating the normal level of oil in the tank.
When engine is an operation, the filter is kept filled with oil up to the level indicated by the gauge. Any makeup oil added to the system should be introduced through the filter.
The filter and screens should be cleaned with kerosene when necessary.
Lubricating Oil Cooler
Lubricating oil cooler is of the multiple tube type. Cooling water enters one end of cooler and is delivered out of the other end. The cooling water tubes are of large diameter, insuring ample supply of cooling water. Cooling water passes through the tubes while the oil passes through the space between the tubes. The lubricating oil passes through the cooler in a direction opposite to that of the cooling water.
Keep tubes clean and joints tight.
Oiling system is of the force-feed type. Oil is forced under pressure to all parts requiring lubrication. A pump draws oil from the oil supply tank through oil cooler and forces it to a header in the crank case, and from this header, oil is delivered to main bearings, then through passages drilled in crankshaft to connecting rod bearings. All lubricating oil drains to crankcase sump. A second pump draws the oil from crankcase sump, forcing it into the filter. A by-pass is fitted on the discharge of the pressure pump in order to regulate the pressure of lubricating oil in manifold by by-passing the discharge to the suction.
The main bearings are supplied with oil under pressure from the oil header, located in the lower crank case. This header runs the entire length of crank case, and individual tubes deliver the oil to top of each bearing at the center. The main bearings all are babbitted and chamfered to allow easy entrance of the oil between the bearing surfaces. An annular groove in each main bearing delivers oil to the crankpin bearings through drilled passages.
The crankpin bearings are supplied with oil by means of passages drilled diagonally through the crankshaft. These bearings are babbitted and chamfered to allow easy entrance of oil to bearing surfaces.
Wrist Pin Bearings
Wrist pin bearings are supplied with oil through a tube running alongside the connecting rod. This tube connects, by means of suitably drilled passages, with the crankpin and wrist pin bearings. A ball check is placed in the middle of this tube, which insures a full supply of oil to the wrist pin bearings when starting the engine.
The wrist pin is hollow and works in piston. The inside of the wrist pin is fitted with tubes leading to the top side of the wrist pin bearing. They carry oil from the connecting rod to the wrist pin bearing surfaces.
The cylinders are lubricated by the oil which is thrown off of the cranks and connecting rod bearings. In order to prevent excess oil working by the piston rings, an oil drain ring is fitted into the bottom piston ring groove, the oil drained by this ring passing to the inside of the piston through drilled passages.
The valves spindles and rocker arm bearings should be oiled regularly.
Selection of Oil
The lubricating oil used should have the proper body, in order that it may be readily pumped through the bearings. An oil too heavy in body will not flow readily, resulting in poor distribution and the formation of carbon deposits within the cylinders. An oil too light in body will fail to maintain a complete oil film on the bearings and cylinders. Experience has proved that the continued efficient operation of an oil engine depends not only on intelligent care and proper fuel, but also very largely on correct lubrication.
Investigation proves that oils which apparently have physical characteristics within limits commonly allowed may have widely different lubricating values in service.
WE RECOMMEND OILS MADE BY REPUTABLE OIL COMPANIES ESPECIALLY FOR DIESEL ENGINE LUBRICATION AND MEETING THE FOLLOWING SPECIFICATIONS:
Gravity-Baume 20º - 30º
Viscosity at 100º F. Not over 1,000"
Viscosity at 210º F. Not less than 75"
Flash Not less than 400º F.
Fire Not less than 425º F.
Carbon residue Not over .90%
A high grade, pure mineral oil of extra heavy body and exceptional lubricating qualities, that meets the above specifications, is suitable for the main lubricating system. A small amount of such oil furnishes and maintains a complete oil film on the power cylinder walls, and effectively seals the pistons notwithstanding the high temperatures and pressures encountered. Also, because of its special characteristics and the small amount necessary to furnish efficient lubrication, such an oil minimizes carbon deposits.
An oil of this kind is practically indestructible, and will, with reasonable care, continue to furnish efficient lubrication for a long time.
TO THE OPERATOR
If the instructions in this book have been carefully read, studied, reasoned out and followed, there is no doubt that the operator will have very little trouble keeping his engine in its very best condition at all times.
Keep these instructions handy. Refer to them continually. They will help you in many ways.
WINTON ENGINE CORP.
Subsidiary of General Motors Corporation
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