Lucas Industries plc was a Birmingham-based British manufacturer of motor industry and aerospace industry components. Once prominent, it was listed on the London Stock Exchange and was a constituent of the FTSE 100 Index. In August 1996, Lucas merged with the American Varity Corporation to form LucasVarity plc. After LucasVarity was sold to TRW the Lucas brand name was licensed for its brand equity to Elta Lighting for aftermarket auto parts in the United Kingdom; the Lucas trademark is owned by ZF Friedrichshafen, which retained the Elta arrangement. In the 1850s, Joseph Lucas, a jobless father of six, sold paraffin oil from a barrow cart around the streets of Hockley. In 1860, he founded the firm, his 17-year-old son Harry joined the firm around 1872. At first it made general pressed metal merchandise, including plant pot holders and buckets, in 1875 lamps for ships. Joseph Lucas & Son was based in Little King Street from 1882 and Great King Street Birmingham. In 1902, what had by become Joseph Lucas Ltd, incorporated in 1898, started making automotive electrical components such as magnetos, windscreen wipers, lighting and starter motors.
The company started its main growth in 1914 with a contract to supply Morris Motors Limited with electrical equipment. During the First World War Lucas made shells and fuses, as well as electrical equipment for military vehicles. Up until the early 1970s, Lucas was the principal supplier to British manufacturers of magnetos, alternators and other electrical components. After the First World War the firm expanded branching out into products such as braking systems and diesel systems for the automotive industry and hydraulic actuators and electronic engine control systems for the aerospace industry. In 1926 they gained an exclusive contract with Austin. Around 1930, Lucas and Smiths established a trading agreement to avoid competition in each other's markets. During the 1920s and 1930s Lucas grew by taking over a number of their competitors such as Rotax and C. A. Vandervell. During WW2 Lucas were engaged by Rover to work on the combustion and fuel systems for the Whittle jet engine project making the burners.
This came about because of their experience of sheet metal manufacture and CAV for the pumps and injectors. In the 1950s they started a semiconductor manufacturing plant to make transistors. In 1976, the militant workforce within Lucas Aerospace were facing significant layoffs. Under the leadership of Mike Cooley, they developed the Lucas Plan to convert the company from arms to the manufacture of useful products, save jobs; the plan was described at the time by the Financial Times as "one of the most radical alternative plans drawn up by workers for their company", by Tony Benn as "one of the most remarkable exercises that has occurred in British industrial history". The Plan took a year to put together, consisted of six volumes of around 200 pages each, included designs for 150 proposed items for manufacture, market analysis and proposals for employee training and restructuring the firm's work organisation; the plan was not put into place but it is claimed that the associated industrial action saved some jobs.
In addition the Plan had an impact outside of Lucas Aerospace: according to a 1977 article in New Statesman, "the philosophical and technical implications of the plan now being discussed on average of twenty five times a week in international media". Workers in other companies subsequently undertook similar initiatives elsewhere in the UK, continental Europe and the United States, the Plan was supported by and influenced the work of radical scientists such as the British Society for Social Responsibility in Science and community and environmental activists through spreading the idea of encouraging useful production; the Plan's proposals had an influence on the economic development strategies of a number of left-wing Labour councils, for example the West Midlands, Sheffield and the Greater London Council, where Cooley was appointed Technology Director of the Greater London Enterprise Board after being sacked by Lucas in 1981 due to his activism. In August 1996, Lucas Industries plc merged with the North American Varity Corporation to form LucasVarity plc.
Its specific history is covered on the LucasVarity page but for the sake of continuity key aspects of the old Lucas business histories to date that referring to CAV and Lucas Diesel Systems are still included here. Harry Lucas designed a hub lamp for use in a high bicycle in 1879 and named the oil lamp "King of the Road"; this name would come to be associated with the manufactured products of Lucas Companies, into the present day. However, Lucas did not use the "King of the Road" epithet for every lamp manufactured, they used this name on only their most prestigious and highest priced lamps and goods. This naming format would last until the 1920s when the "King of the Road" wording was pressed into the outer edge of the small "lion and torch" button motifs that decorated the tops of both bicycle and motor-car lamps; the public were encouraged by Lucas to refer to every Lucas lamp as a "King of the Road", but speaking, this is quite wrong, as most lamps throughout the 20th century possessed either a name, a number, or both.
Joseph and Harry Lucas formed a joint stock corporation with the New Departure Bell Co. of America in 1896, so that Lucas designed bicycle lamps could be manufactured in America to avoid import duties. The King of the Road name returned in 2013 as Lucas Electrical reintroduced a range of bicycle lighting to the UK
An Injection Pump is the device that pumps diesel into the cylinders of a diesel engine. Traditionally, the injection pump is driven indirectly from the crankshaft by gears, chains or a toothed belt that drives the camshaft, it rotates at half crankshaft speed in a conventional four-stroke diesel engine. Its timing is such that the fuel is injected only slightly before top dead centre of that cylinder's compression stroke, it is common for the pump belt on gasoline engines to be driven directly from the camshaft. In some systems injection pressures can be as high as 220 bar; because of the need for positive injection into a high-pressure environment, the pump develops great pressure—typically 15,000 psi or more on newer systems. This is a good reason to take great care. Earlier diesel pumps used an in-line layout with a series of cam-operated injection cylinders in a line, rather like a miniature inline engine; the pistons have a constant stroke volume, injection volume is controlled by rotating the cylinders against a cut-off port that aligns with a helical slot in the cylinder.
When all the cylinders are rotated at once, they vary their injection volume to produce more or less power from the engine. Inline pumps still find favour on large multi-cylinder engines such as those on trucks, construction plant, static engines and agricultural vehicles. For use on cars and light trucks, the rotary pump or distributor pump was developed, it uses a single injection cylinder driven from an axial cam plate, which injects into the individual fuel lines via a rotary distribution valve. Incarnations such as the Bosch VE pump vary the injection timing with crankshaft speed to allow greater power at high crank speeds, smoother, more economical running at slower revolution of crankshaft; some VE variants have a pressure-based system that allows the injection volume to increase over normal to allow a turbocharger or supercharger equipped engine to develop more power under boost conditions. All injection pumps incorporate a governor to cut fuel supply if the crankshaft rpm endangers the engine - the heavy moving parts of diesel engines do not tolerate overspeeding well, catastrophic damage can occur if they are over-revved.
Poorly maintained and worn engines can consume their lubrication oil through worn out crankcase ventilation systems and'run away', causing increasing engine speed until the engine destroys itself. This is because most diesel engines only regulate their speed by fuel supply control and don't have a throttle valve to control air intake. Mechanical pumps are being phased out in order to comply with international emissions directives, to increase performance and economy. From the 1990s an intermediate stage between full electronic control were pumps that used electronic control units to control some of the functions of the rotary pump but were still mechanically timed and powered by the engine; the first generation four and five cylinder VW/Audi TDI engines pioneered these pumps before switching to Unit Injectors. These pumps were used to provide better injection control and refinement for car diesel engines as they changed from indirect injection to much more efficient but inherently less refined direct injection engines in the 1990s.
The ECUs could vary the damping of hydraulic engine mounts to aid refinement. BOSCH VP30 VP37 VP44 are example pumps. Since there has been a widespread change to common rail diesel systems and electronic unit direct injection systems; these allow for higher pressures to be developed, for much finer control of injection volumes, multiple injection stages compared to mechanical systems. Unit injector
Navistar International Corporation is an American holding company, that owns the manufacturer of International brand commercial trucks, IC Bus school and commercial buses, Workhorse brand chassis for motor homes and step vans, is a private label designer and manufacturer of diesel engines for the pickup truck, SUV markets. The company is a provider of truck and diesel engine parts and service. Headquartered in Lisle, Navistar has 16,500 employees and a 2013 annual revenue of $10.775 billion. The company's products and services are sold through a network of nearly 1,000 dealer outlets in the United States, Canada and Mexico and more than 60 dealers in 90 countries throughout the world; the company provides financing for its customers and distributors principally through its wholly owned subsidiary, Navistar Financial Corporation. The merger of McCormick Harvesting Machine Company and the Deering Harvester Company in 1902 resulted in the formation of the International Harvester Company of Chicago, which over the next three-quarters of a century evolved to become a diversified manufacturer of farming equipment, construction equipment, gas turbines, trucks and related components.
During World War II, International Harvester produced the M-series of military trucks that served the Marine Corps and the U. S. Navy as weapons carriers, cargo transporters and light artillery movement. Today, Navistar produces International brand military vehicles through its affiliate Navistar Defense. Ford had Navistar under-contract that same year to produce engines for their passenger fleet of work light work trucks. International Harvester fell on hard times during the poor agricultural economy in the early to mid-1980s and the effects of a long strike with the UAW over proposed work rule changes. IH's new CEO, Donald Lennox, directed the management organization to begin exiting many of its IH's historical business sectors in an effort to survive; some of the sales of profitable business endeavors were executed to raise cash for short-term survival, while other divisions were sold due to lack of immediate profitability. During this period of questionable economic survival, in an effort to raise needed cash and to reduce losses, the management team led by Mr. Lennox at IH shed many of its operating divisions: Construction Equipment Division to Dresser Industries.
I. Case subsidiary; the Scout and Light Truck Parts Business was sold to Scout/Light Line Distributors, Inc. in 1991. After the Agricultural Division sale in 1985, all that remained of IH were the Truck and Engine Divisions; the company rechristened itself on February 20, 1986 to Navistar International Corporation.. In the early 1980s, IH developed a series of reliable large-displacement V8 diesel engines that were sold as an option for heavy-duty Ford 3/4-ton and 1-ton pickup trucks. Navistar still uses the "International" brand in its diesel engine and truck product lines, the brand name continues on in product lines of Navistar International's International Truck and Engine Corporation subsidiary. During the 1980s and 1990s, the popularity of diesel engines had made Navistar a leading manufacturer of bus chassis school buses; the company purchased one-third of American Transportation Corporation, an Arkansas-based manufacturer in 1991, the remaining two-thirds in April 1995. By becoming both a body and chassis manufacturer at the same time, Navistar gained significant market share in the industry.
In 2002, AmTran was rebranded as IC after a few months as International Bus. After nearly a century of business in Chicago, Navistar announced its plans on 30 September 2000 to leave the city and relocate its corporate offices to west suburban Warrenville, Illinois; the company's Melrose Park, Illinois plant is notable for a significant workplace shooting on February 5, 2001. In 2004, Navistar re-entered the retail vehicle market for the first time since 1980; the International XT pickup truck was a series of three pickup trucks. It was the largest pickup truck available for retail sale and two of the three versions were International Durastar medium-duty trucks fitted with pickup beds; the third version was a street-legal version of a Navistar-designed military vehicle. The three XT trucks were sold until 2008. In 2005, Navistar purchased the Workhorse company, a manufacturer of step-van and motor home chassis, to re-enter the delivery van market, it appeared that the new subsidiary might benefit by its association with a company whose history from the 1930s into the'60s included the popular Metro van.
For a short time Workhorse offered. In Sept. of 2012, Navistar announced the shut down of Workhorse and the closure of the plant in Union City, Indiana in order to cut costs. Workhorse has since repositioned itself as a manufacturer of electrically powered trucks and delivery vans. In January 2006, the company declared it would not file its form 10-K annual report with the U. S. Securities and Exchange Commission on time; the delay was caused by the disagreement with its auditors, Deloitte &
Caterpillar Inc. is an American Fortune 100 corporation which designs, engineers, manufactures and sells machinery, financial products and insurance to customers via a worldwide dealer network. It is the world's largest construction equipment manufacturer. In 2018, Caterpillar was ranked # 65 on # 238 on the Global Fortune 500 list. Caterpillar stock is a component of the Dow Jones Industrial Average. Caterpillar Inc. traces its origins to the 1925 merger of the Holt Manufacturing Company and the C. L. Best Tractor Company, creating the California-based Caterpillar Tractor Company. In 1986, the company reorganized itself as a Delaware corporation under the current name, Caterpillar Inc. Caterpillar's headquarters are located in Illinois; the company licenses and markets a line of clothing and workwear boots under its Cat / Caterpillar name. Caterpillar machinery is recognizable by its trademark "Caterpillar Yellow" livery and the "CAT" logo; the steam tractors of the 1890s and early 1900s were heavy, sometimes weighing 1,000 pounds per horsepower, sank into the rich, soft earth of the San Joaquin Valley Delta farmland surrounding Stockton, California.
Benjamin Holt attempted to fix the problem by increasing the size and width of the wheels up to 7.5 feet tall and 6 feet wide, producing a tractor 46 feet wide. But this made the tractors complex and difficult to maintain. Another solution considered was to lay a temporary plank road ahead of the steam tractor, but this was time-consuming and interfered with earthmoving. Holt thought of wrapping the planks around the wheels, he replaced the wheels on No. 77, with a set of wooden tracks bolted to chains. On Thanksgiving Day, November 24, 1904, he tested the updated machine plowing the soggy delta land of Roberts Island. Contemporaneously Richard Hornsby & Sons in Grantham, England, developed a steel plate tracked vehicle which it patented in 1904; this tractor steered by differential braking of the tracks and did not require the forward tiller steering wheel for steering making it the first to do so. Several tractors were made and sold to operate in the Yukon, one example of, in operation until 1927 remnants of which still exist to this day, but Hornsby were unable to interest the British Military in 1907, although soldiers who witnessed the trials nicknamed the machine a caterpillar.
Hornsby therefore found a limited market for their tractor so they sold their patent to Holt in 1911, the same year Holt trademarked "Caterpillar". Company photographer Charles Clements was reported to have observed that the tractor crawled like a caterpillar, Holt seized on the metaphor. "Caterpillar it is. That's the name for it!" Some sources, attribute this name to British soldiers in July 1907. Two years Holt sold his first steam-powered tractor crawlers for US$5,500, about US$128,000 today; each side were 9 feet long. The tracks were 3 inches by 4 inches redwood slats. Holt received the first patent for a practical continuous track for use with a tractor on December 7, 1907 for his improved "Traction Engine". On February 2, 1910, Holt opened up a plant in East Peoria, led by his nephew Pliny Holt. There Pliny met farm implement dealer Murray Baker who knew of an empty factory, built to manufacture farm implements and steam traction engines. Baker, who became the first executive vice president of what became Caterpillar Tractor Company, wrote to Holt headquarters in Stockton and described the plant of the bankrupt Colean Manufacturing Co. of East Peoria, Illinois.
On October 25, 1909, Pliny Holt purchased the factory, began operations with 12 employees. Holt incorporated it as the Holt Caterpillar Company, although he did not trademark the name Caterpillar until August 2, 1910; the addition of a plant in the Midwest, despite the hefty capital needed to retool the plant, proved so profitable that only two years the company employed 625 people and was exporting tractors to Argentina and Mexico. Tractors were built in both East Peoria. On January 31, 2017, after more than 90 years of being headquartered in Peoria, the company announced plans to move their headquarters from Peoria to Chicago, Illinois by the end of 2017; the upper echelon of executives, including newly installed CEO Jim Umpleby, would begin relocating that year, with up to 100 employees total moving by year's end. About 300 employees will work in the new office at an as-yet undecided location once the transition is complete; the company indefinitely suspended planning for the new Peoria headquarters in the fall of 2015 after announcing a restructuring effort that called for up to 10,000 jobs to be cut and about 20 facilities around the world to be closed or consolidated.
The changes contributed to $2.3 billion in savings in 2016, but sales and revenue for last year still were more than 40 percent below peak levels of 2012. Umpleby said that decline is a fundamental reason the company's Board of Directors opted to move global headquarters to an area where the global marketplace is in easier reach; the first tanks used in WW1 were manufa
The Diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel, injected into the combustion chamber, is caused by the elevated temperature of the air in the cylinder due to the mechanical compression. Diesel engines work by compressing only the air; this increases the air temperature inside the cylinder to such a high degree that atomised Diesel fuel injected into the combustion chamber ignites spontaneously. With the fuel being injected into the air just before combustion, the dispersion of the fuel is uneven; the process of mixing air and fuel happens entirely during combustion, the oxygen diffuses into the flame, which means that the Diesel engine operates with a diffusion flame. The torque a Diesel engine produces is controlled by manipulating the air ratio; the Diesel engine has the highest thermal efficiency of any practical internal or external combustion engine due to its high expansion ratio and inherent lean burn which enables heat dissipation by the excess air.
A small efficiency loss is avoided compared with two-stroke non-direct-injection gasoline engines since unburned fuel is not present at valve overlap and therefore no fuel goes directly from the intake/injection to the exhaust. Low-speed Diesel engines can reach effective efficiencies of up to 55%. Diesel engines may be designed as either four-stroke cycles, they were used as a more efficient replacement for stationary steam engines. Since the 1910s they have been used in ships. Use in locomotives, heavy equipment and electricity generation plants followed later. In the 1930s, they began to be used in a few automobiles. Since the 1970s, the use of Diesel engines in larger on-road and off-road vehicles in the US has increased. According to Konrad Reif, the EU average for Diesel cars accounts for 50% of the total newly registered; the world's largest Diesel engines put in service are 14-cylinder, two-stroke watercraft Diesel engines. In 1878, Rudolf Diesel, a student at the "Polytechnikum" in Munich, attended the lectures of Carl von Linde.
Linde explained that steam engines are capable of converting just 6-10 % of the heat energy into work, but that the Carnot cycle allows conversion of all the heat energy into work by means of isothermal change in condition. According to Diesel, this ignited the idea of creating a machine that could work on the Carnot cycle. After several years of working on his ideas, Diesel published them in 1893 in the essay Theory and Construction of a Rational Heat Motor. Diesel was criticised for his essay, but only few found the mistake that he made. Diesel's idea was to compress the air so that the temperature of the air would exceed that of combustion. However, such an engine could never perform any usable work. In his 1892 US patent #542846 Diesel describes the compression required for his cycle: "pure atmospheric air is compressed, according to curve 1 2, to such a degree that, before ignition or combustion takes place, the highest pressure of the diagram and the highest temperature are obtained-that is to say, the temperature at which the subsequent combustion has to take place, not the burning or igniting point.
To make this more clear, let it be assumed that the subsequent combustion shall take place at a temperature of 700°. In that case the initial pressure must be sixty-four atmospheres, or for 800° centigrade the pressure must be ninety atmospheres, so on. Into the air thus compressed is gradually introduced from the exterior finely divided fuel, which ignites on introduction, since the air is at a temperature far above the igniting-point of the fuel; the characteristic features of the cycle according to my present invention are therefore, increase of pressure and temperature up to the maximum, not by combustion, but prior to combustion by mechanical compression of air, there upon the subsequent performance of work without increase of pressure and temperature by gradual combustion during a prescribed part of the stroke determined by the cut-oil". By June 1893, Diesel had realised his original cycle would not work and he adopted the constant pressure cycle. Diesel describes the cycle in his 1895 patent application.
Notice that there is no longer a mention of compression temperatures exceeding the temperature of combustion. Now it is stated that the compression must be sufficient to trigger ignition. "1. In an internal-combustion engine, the combination of a cylinder and piston constructed and arranged to compress air to a degree producing a temperature above the igniting-point of the fuel, a supply for compressed air or gas. See US patent # 608845 filed 1895 / granted 1898In 1892, Diesel received patents in Germany, the United Kingdom and the United States for "Method of and Apparatus for Converting Heat into Work". In 1894 and 1895, he filed patents and addenda in various
Two-stroke diesel engine
A two-stroke diesel engine is a Diesel engine that works in two strokes. It was invented by Hugo Güldner in 1899. Charles F. Kettering and colleagues, working at the General Motors Research Corporation and GM's subsidiary Winton Engine Corporation during the 1930s, advanced the art and science of two-stroke diesel technology to yield engines with much higher power-to-weight ratios and output range than contemporary four-stroke diesels; the first mobile application of two-stroke diesel power was with the diesel streamliners of the mid-1930s and continued development work resulted in improved two-stroke diesels for locomotive and marine applications in the late 1930s. This work laid the foundation for the dieselisation of railroads in the 1950s. All diesel engines use compression ignition, a process by which fuel is injected after the air is compressed in the combustion chamber, thereby causing the fuel to self-ignite. By contrast, gasoline engines utilize the Otto cycle, or, more the Atkinson cycle, in which fuel and air are mixed before entering the combustion chamber and ignited by a spark plug.
Two-stroke internal combustion engines are simpler mechanically than four-stroke engines, but more complex in thermodynamic and aerodynamic processes, according to SAE definitions. In a two-stroke engine, the four "cycles" of internal combustion engine theory occur in one revolution, 360 mechanical degrees, whereas in a four-stroke engine these occur in two complete revolutions, 720 mechanical degrees. In a two-stroke engine, more than one function occurs at any given time during the engine's operation. Intake begins. Air is admitted to the cylinder through ports in the cylinder wall. All two-stroke Diesel engines require artificial aspiration to operate, will either use a mechanically driven blower or a turbo-compressor to charge the cylinder with air. In the early phase of intake, the air charge is used to force out any remaining combustion gases from the preceding power stroke, a process referred to as scavenging; as the piston rises, the intake charge of air is compressed. Near top dead center, fuel is injected, resulting in combustion due to the charge's high pressure and heat created by compression, which drives the piston downward.
As the piston moves downward in the cylinder, it will reach a point where the exhaust port is opened to expel the high-pressure combustion gasses. However, most current two-stroke diesel engines use top-mounted poppet valves and uniflow scavenging. Continued downward movement of the piston will expose the air intake ports in the cylinder wall, the cycle will start again. In most EMD and GM two-stroke engines few parameters are adjustable and all the remaining ones are fixed by the mechanical design of the engines; the scavenging ports are open from 45 degrees before BDC, to 45 degrees after BDC. The remaining, parameters have to do with exhaust valve and injection timing, they are established to maximize combustion gas exhaust and to maximize charge air intake. A single camshaft operates the poppet-type exhaust valves and the Unit injector, using three lobes: two lobes for exhaust valves. Specific to EMD two-stroke engines: The power stroke begins at TDC, after the power stroke the exhaust valves are opened, thereby reducing combustion gas pressure and temperature, preparing the cylinder for scavenging, for a power stroke duration of 103°.
Scavenging begins 32° at BDC–45°, ends at BDC+45°, for a scavenging duration of 90 degrees. Towards the end of scavenging, all products of combustion have been forced out of the cylinder, only "charge air" remains; the compression stroke begins 16° at BDC+61°, for a compression stroke duration of 119°. In EFI-equipped engines, the electronically-controlled unit injector is still actuated mechanically. Specific to GM two-stroke and related on-road/off-road/marine two-stroke engines: The same basic considerations are employed. Whereas some EMD and Detroit Diesel engines employ turbocharging, only such EMD engines employ a turbo-compressor system.
The EMD 710 is a line of diesel engines built by Electro-Motive Diesel. The 710 series replaced the earlier EMD 645 series when the 645F series proved to be unreliable in the early 1980s 50-series locomotives which featured a maximum engine speed of 950 rpm; the EMD 710 is a large medium speed two-stroke diesel engine that has 710 cubic inches displacement per cylinder, a maximum engine speed of 900 rpm. In 1951, E. W. Kettering wrote a paper for the ASME entitled and Development of the 567 Series General Motors Locomotive Engine, which goes into great detail about the technical obstacles that were encountered during the development of the 567 engine; these same considerations apply to the 645 and 710, as these engines were a logical extension of the 567C, by applying a cylinder bore increase, a stroke increase, to achieve a greater power output, without changing the external size of the engines, or their weight, thereby achieving significant improvements in horsepower per unit volume and horsepower per unit weight.
Since its introduction, EMD has continually upgraded the 710G diesel engine. Power output has increased from 3,800 horsepower on 1984's 16-710G3A to 4,500 horsepower on the 16-710G3C-T2, although most current examples are 4,300 horsepower; the 710 has proved to be exceptionally reliable, but the earlier 645 is still supported and most 645 service parts are still in new production, as many 645E-powered GP40-2 and SD40-2 locomotives are still operating after four decades of trouble-free service, these serve as a benchmark for engine reliability, which the 710 would meet and exceed, quite a number of non-SD40-2 locomotives, have been rebuilt to the equivalent of SD40-2s with new or remanufactured engines and other subsystems, using salvaged locomotives as a starting point. Some of these rebuilds have been made using new 12-cylinder 710 engines in place of the original 16-cylinder 645 engines. Over the production span of certain locomotive models, upgraded engine models have been fitted when these became available.
For example, an early 1994-built SD70MAC had a 16-710G3B, whereas a 2003-built SD70MAC would have a 16-710G3C-T1. The engine is made in V-8, V-12, V-16, V-20 configurations, although most current locomotive production is the V-16 engine, whereas most current marine and stationary engine production is the V-20 engine. All 710 engines are two-stroke 45 degree V-engines; the 710, the earlier 645 and 567, are the only two-stroke engines used today in locomotives. The 710 model was introduced in 1985 and has a 1-inch longer stroke than the 645; the engine is a uniflow design with four poppet-type exhaust valves in the cylinder head. For maintenance, a power assembly, consisting of a cylinder head, cylinder liner, piston carrier, piston rod can be individually and easily and replaced; the block is made from flat and rolled structural steel members and steel forgings welded into a single structure. Blocks may, therefore, be repaired, if required, using conventional shop tools; each bank of cylinders has a camshaft which operates the Unit injectors.
Pre-1995 engines have mechanically controlled unit injectors, patented in 1934 by General Motors, EMD's former owner. Post-1995 engines have electronically controlled unit injectors which fit within the same space as a unit injector. An EUI is EMD's implementation of EFI on its large-displacement diesel engines. See EMD 645 for general specifications common to all 567, 645, 710 engines. Unlike the two earlier engines, which could use either a Roots blower or a turbocharger, the 710 engine is offered only with turbocharging; the turbocharger follows EMD's innovative design that uses a gear train and over-running clutch to drive the compressor rotor. This system acts as a centrifugal blower, during low engine speed, when exhaust gas temperature alone is insufficient to drive the turbine. At higher engine speeds, increased exhaust gas temperature is sufficient to drive the turbine, the clutch disengages, acts as a true centrifugal turbocharger; the turbo-compressor can revert to compressor mode momentarily during demands for large increases in engine output power.
While more expensive to maintain than Roots blowers, the turbocharger reduces fuel consumption and emissions, while improving high-altitude performance. Additionally, EMD's turbo-compressor can provide a 50 percent increase in maximum rated horsepower over Roots-blown engines for the same engine displacement. But, unlike the earlier 645 and 567, which offered both Roots-blown and turbocharging, EMD's turbo-compressor is an integral part of all 710 models, therefore this 50 percent increase is incorporated into the maximum rated power of all 710 models; the putative horsepower of an otherwise equivalent displacement but Roots-blown, aspirated, 710 may be approximated by multiplying the turbocharged horsepower by 0.67. Horsepower for any aspirated engine is derated 2.5 percent per 1,000 feet above mean sea level, a tremendous penalty at the 10,000 feet or greater elevations which several Western U. S. and Canada railroads operate. Turbocharging eliminates this derating. Certain models have engine controls that permit lower fuel consumption or lower emissions (possibly at the expense of higher fuel consump