Ask Joe Mechanic - Engine Flushing

A hotly debated subject is engine flushing and whether it is beneficial or it is actually harmful to an engine. No two technicians seem to agree as to whether you should perform this service on your vehicle.    

The process of engine flushing is used to clean sludge, dirt and deposits that build up in the internal parts of an engine, especially inside the valve cover and the oil pan over time. The main purpose of performing an engine flush is to try to extend the life of the engine. By flushing an engine periodically, the inside of the engine will hopefully stay relatively clean and will operate more efficiently. 

The method used to flush an engine is somewhat like what is used to flush a transmission. When flushing a transmission, the fluid is pushed through the transmission to carry the old fluid and dirt and deposits out of the transmission by way of the drain plug. With engine flushing, a cleaning chemical is added to the engine oil and circulates through the lubrication system. The chemicals eat away at the deposits, eventually making their way into the oil pan, where they collect in the bottom of the pan to allow it to be drained.

While the theory behind flushing an engine seems like something that should be done on a periodic basis, there is much disagreement as to whether it is smart and effective to do. While it is general knowledge that it can be beneficial in low mileage vehicles that have not had proper maintenance performed, something that is often found to happen in lease vehicles where the leasee feels that it is not my vehicle and I am giving it back in two or three years, so why worry about changing oil and spending that extra money. Many technicians question whether it is a good idea in higher mileage vehicles. There is the chance in an older engine that the buildup of sludge may be more than the chemicals in the flush can properly loosen and remove, which could worsen a bad situation. Another fear is that the sludge will lie in the pan and clog the oil pump pickup screen and cause oil starvation. Instead of performing an engine flush, it is much more effective to disassemble and clean the engine as long as it is in good operating condition, even though this is more expensive, or else do a complete engine rebuild if it is determined that the engine is not in good condition. 

Because there is such a difference of opinion whether to do an engine flush or not, not every garage offers or recommends this service. Some facilities that used to do engine flushes, including a dealer where I used to work, no longer do so. Even in shops that do engine flushes, they will generally have a technician check the condition of the engine before they will do the flush. 

It is important to remember that there is no substitute for proper maintenance. If anything, an engine flush should be considered as a way to supplement the proper care of the engine and thereby help to prolong its life. Also, if you do choose to perform this service, I recommend having a professional do it and seek their advice first, I do not consider this a wise do it yourself procedure.

Ask Joe Mechanic - Diesel Engine Vehicles (Part 4)

            We have now pretty much covered the workings and the advantages and concerns about diesel engine vehicles. The only things remaining are why they are so poorly accepted in the USA compared to the rest of the world and also what are the current and future diesel engine vehicles that are available to us.

            In the United States, diesels presently account for only about three percent of the personal transportation vehicles on the road today. In Europe, the average is about 50 percent, with France having the highest total at about 70 percent diesels. Germany is about 50 percent, which includes almost all police cars and taxis, while England rates about 38 percent. If diesels rate so much better fuel economy and engine longevity, what is the reason for this disparity? Actually, the reasons are many, and there is enough blame to cover almost everyone. From government regulations to US automakers mistakes and indifference to public perceptions and misinformation, there is much fault to find.

            The first subject is government regulations. In Europe, the governments encourage the use of diesel by taxing diesel fuel is taxed at a rate of about one half what gasoline is taxed. In the United States, federal fuel tax is 18.4 cents per gallon on gasoline while it is 24.4 cents on diesel. Also, our government subsidizes the making of ethanol despite the fuel’s terrible economics and its impact on the environment as a whole (ethanol takes a great deal of energy to produce which contributes to greenhouse gases and global warming), and also requires extensive modifications to the engine and fuel system to allow its use. On the other hand, biodiesel can be better for the environment, requires much less energy to create, utilizes food waste to produce, and also requires little or no modification to a diesel engine to use. Biodiesel is also carbon neutral, which appeals to environmentally conscious consumers.

            As far as other environmental impacts, while it is true that diesels emit more particulates per gallon burned than gasoline does, there is something skewed in the way the government calculates it. If one vehicle emits 1 percent noxious oxides into the environment and another emits 1.5 percent, which is better for the environment? Clearly the one emitting 1.5 percent if it achieved twice the mileage of the other! But the government does not see it that way. Everything works by proportion, so a thrifty Toyota Corolla is judge by the same standard as a gas hog Cadillac or even worse a heavy duty GMC Yukon, which is still considered better than a VW Jetta TDI.

           

And, while we are familiar with the fleet average mileage law, there is also a much lesser known fleet average emissions law. This is why almost every year Volkswagen runs out of turbo-diesels part way through the year. And in some states such as California, New York, Massachusetts and Maine, they have even more stringent regulations. In California, there is a regulation on the number of one-ton diesel vehicles allowed to be sold each year. For this reason, in California, you do not find Dodge offering diesels in anything except its high profit Ram trucks. And, even though it is powered by a small, highly fuel efficient diesel, the Freightliner Sprinter was delayed a year being introduced into those states because it was a diesel only vehicle, unlike Dodge which had gas and diesel versions and came to market a year sooner.

            The second reason is the US automakers. As we have already seen, in certain places, vehicles are released based on profit margin only. In Europe, Dodge sells diesel-powered caravans, which amount to between 75 and 80 percent of European Caravan sales. Dodge also released diesel powered Neons and PT Cruisers for the European market.  Another factor is that US automakers have always charged a substantially higher price for a comparably equipped diesel powered vehicle. This, combined with the higher diesel fuel price has discouraged the American public from spending the extra dollars.

           

But, probably the biggest problem created by the manufacturers, which affected the sale of diesels in the United States, occurred during the first oil crisis in the 1970s.

Several manufacturers, most notably General Motors in an attempt to rush diesels into the US market, converted gasoline engines into diesels without strengthening the engine block to handle the much higher compression. The engines were very unreliable and basically at times blew up without warning, sometimes with very low mileage on them. These, combined with the fact that these older diesels were very sluggish on performance, smoked, and were very noisy; left a very bad taste in the American car buying publics’ mouth toward diesel engines.

           

Many of the public perceptions of diesels, noise, smoke; vibration, poor acceleration and cost have been addressed with the newest generations of diesels. Better balancing and injection systems have lessened the noise and vibration. Smoke and smell have pretty much been eliminated with the new ultra low sulfur fuels. Poor acceleration has been eliminated by new cylinder head designs, fuel injection improvements and turbocharging. And many manufacturers have eliminated the surcharge for a diesel or at least reduced it to a reasonable amount.

            While for years, Mercedes Benz, Volkswagen and a few other small companies were the only ones offering diesel powered vehicles in the United States; there are now quite a few choices available in many different size and types of vehicles. And, very soon, Ford, General Motors and Chrysler will be offering diesels in the domestic marketplace.

            I personally can attest to the strength and reliability of diesel engines. I grew up around diesels as my father has driven them since the late 1950’s. He had a number of 170, 180, 190, and 240 Mercedes Diesels along with a few Peugeot 504s. His 1953 Mercedes 170DS was actually in the Guinness Book of World Records with the highest documented mileage vehicle in the world in 1979 and 1980. His Mercedes had 844,000 miles on it, and basically we did all the work on the car at home. We rebuilt the transmission or engine, replaced head gaskets or whatever work was required to keep it on the road. My father worked in Philadelphia for 14 years and commuted every day, for one 14-month period working seven days a week. There were times on extremely cold winter days, that for fear of not being able to start the car when he came out of work, he would lock the car and let it idle all day. The only times he would take the car to the shop was for state inspections or to the dealer each time it turned another 100,000 so that it could be duly noted. In addition to the mileage awards he received from Mercedes for this car, they also recognized him for 1,500,000 combined miles on his various Mercedes. Mercedes actually took the engine and transmission from his car and sent them back to Germany where the training school rebuilt and restored them for him. Also, when I traveled to Germany in 1980 while they went there for vacation, my father and I received a personally guided tour of the Mercedes Museum by its Curator, in spite of fact that the Museum was closed at the time.

Ask Joe Mechanic - Diesel Engines (Part 2)

The first subject of this week’s article is how a diesel engine operates. The diesel internal combustion engine differs from the gasoline powered Otto cycle by using highly compressed hot air to ignite the fuel rather than using a spark plug (compression ignition rather than spark ignition).

In the true diesel engine, only air is initially introduced into the combustion chamber. The air is then compressed with a compression ratio typically between 15:1 and 22:1 resulting in 40-bar (4.0 MPa; 580 psi) pressure compared to 8 to 14 bars (0.80 to 1.4 MPa; 120 to 200 psi) in the petrol engine. This high compression heats the air to 550 °C (1,022 °F). At about the top of the compression stroke, fuel is injected directly into the compressed air in the combustion chamber. This may be into a (typically toroidal) void in the top of the piston or a pre-chamber depending upon the design of the engine. The fuel injector ensures that the fuel is broken down into small droplets, and that the fuel is distributed evenly. The heat of the compressed air vaporizes fuel from the surface of the droplets. The heat from the compressed air in the combustion chamber then ignites the vapor; the droplets continue to vaporize from their surfaces and burn, getting smaller, until all the fuel in the droplets has been burnt. The start of vaporization causes a delay period during ignition and the characteristic diesel knocking sound as the vapor reaches ignition temperature and causes an abrupt increase in pressure above the piston. The rapid expansion of combustion gases then drives the piston downward, supplying power to the crankshaft.

As well as the high level of compression allowing combustion to take place without a separate ignition system, a high compression ratio greatly increases the engine's efficiency. Increasing the compression ratio in a spark-ignition engine where fuel and air are mixed before entry to the cylinder is limited by the need to prevent damaging pre-ignition. Since only air is compressed in a diesel engine, and fuel is not introduced into the cylinder until shortly before top dead centre (TDC), premature detonation is not an issue and compression ratios are much higher.

Diesel's original engine injected fuel with the assistance of compressed air, which atomized the fuel and forced it into the engine through a nozzle (a similar principle to an aerosol spray). The nozzle opening was closed by a pin valve lifted by the camshaft to initiate the fuel injection before top dead centre (TDC). This is called an air-blast injection. Driving the three-stage compressor used some power but the efficiency and net power output was more than any other combustion engine at that time.

Diesel engines in service today raise the fuel to extreme pressures by mechanical pumps and deliver it to the combustion chamber by pressure-activated injectors without compressed air. With direct injected diesels, injectors spray fuel through 4 to 12 small orifices in its nozzle. The early air injection diesels always had a superior combustion without the sharp increase in pressure during combustion. Research is now being performed and patents are being taken out to again use some form of air injection to reduce the nitrogen oxides and pollution, reverting to Diesel's original implementation with its superior combustion and possibly quieter operation. In all major aspects, the modern diesel engine holds true to Rudolf Diesel's original design, that of igniting fuel by compression at an extremely high pressure within the cylinder. With much higher pressures and high technology injectors, present-day diesel engines use the so-called solid injection system applied by Herbert Akroyd Stuart for his hot bulb engine. The indirect injection engine could be considered the latest development of these low speed hot bulb ignition engines.

A vital component of all diesel engines is a mechanical or electronic governor which regulates the idling speed and maximum speed of the engine by controlling the rate of fuel delivery. Unlike Otto-cycle engines, incoming air is not throttled and a diesel engine without a governor cannot have a stable idling speed and can easily overspeed, resulting in its destruction. Mechanically governed fuel injection systems are driven by the engine's gear train. 

These systems use a combination of springs and weights to control fuel delivery relative to both load and speed. Modern electronically controlled diesel engines control fuel delivery by use of an electronic control module (ECM) or electronic control unit (ECU). The ECM/ECU receives an engine speed signal, as well as other operating parameters such as intake manifold pressure and fuel temperature, from a sensor and controls the amount of fuel and start of injection timing through actuators to maximize power and efficiency and minimize emissions. Controlling the timing of the start of injection of fuel into the cylinder is a key to minimizing emissions, and maximizing fuel economy (efficiency), of the engine. The timing is measured in degrees of crank angle of the piston before top dead centre. For example, if the ECM/ECU initiates fuel injection when the piston is 10° before TDC, the start of injection, or timing, is said to be 10° BTDC. Optimal timing will depend on the engine design as well as its speed and load.

Advancing the start of injection (injecting before the piston reaches to its SOI-TDC) results in higher in-cylinder pressure and temperature, and higher efficiency, but also results in increased engine noise due to faster cylinder pressure rise and increased oxides of nitrogen (NO_x) formation due to higher combustion temperatures. Delaying start of injection causes incomplete combustion; reduced fuel efficiency and an increase in exhaust smoke, containing a considerable amount of particulate matter and unburned hydrocarbons.

Diesel engines have several advantages over other internal combustion engines:

• They burn less fuel than a petrol engine performing the same work, due to the engine's higher temperature of combustion and greater expansion ratio. Gasoline engines are typically 30 percent efficient while diesel engines can convert over 45 percent of the fuel energy into mechanical.
• They have no high voltage electrical ignition system, resulting in high reliability and easy adaptation to damp environments. The absence of coils, spark plug wires, etc., also eliminates a source of radio frequency emissions, which can interfere with navigation and communication equipment, which is especially important in marine and aircraft applications.
• The life of a diesel engine is generally about twice as long as that of a petrol engine due to the increased strength of parts used. Diesel fuel has better lubrication properties than petrol as well.
• Diesel fuel is distilled directly from petroleum. Distillation yields some gasoline, but the yield would be inadequate without catalytic reforming, which is a more costly process.
• Diesel fuel is considered safer than petrol in many applications. Although diesel fuel will burn in open air using a wick, it will not explode and does not release a large amount of flammable vapor. The low vapor pressure of diesel is especially advantageous in marine applications, where the accumulation of explosive fuel-air mixtures is a particular hazard. For the same reason, diesel engines are immune to vapor lock.
• For any given partial load the fuel efficiency (mass burned per energy produced) of a diesel engine remains nearly constant, as opposed to petrol and turbine engines, which use proportionally more fuel with partial power outputs. They generate less waste heat in cooling and exhaust.
•  Diesel engines can accept super- or turbo-charging pressure without any natural limit, constrained only by the strength of engine components. This is unlike petrol engines, which inevitably suffer detonation at higher pressure.
• The carbon monoxide content of the exhaust is minimal; therefore diesel engines are used in underground mines.
• Biodiesel is an easily synthesized, non-petroleum-based fuel (through transesterification) which can run directly in many diesel engines, while gasoline engines either need adaptation to run synthetic fuels or else use them as an additive to gasoline (e.g., ethanol added to gasohol).
  
  
  
  Many configurations of fuel injection have been used over the course of the twentieth century. Most present-day diesel engines use a mechanical single plunger high-pressure fuel pump driven by the engine crankshaft. For each engine cylinder, the corresponding plunger in the fuel pump measures out the correct amount of fuel and determines the timing of each injection. These engines use injectors that are very precise spring-loaded valves that open and close at a specific fuel pressure. Separate high-pressure fuel lines connect the fuel pump with each cylinder. Fuel volume for each single combustion is controlled by a slanted groove in the plunger, which rotates only a few degrees releasing the pressure, and is controlled by a mechanical governor, consisting of weights rotating at engine speed constrained by springs and a lever. The injectors are held open by the fuel pressure. On high-speed engines the plunger pumps are together in one unit. The length of fuel lines from the pump to each injector is normally the same for each cylinder in order to obtain the same pressure delay.
  
  
  
  
  A cheaper configuration on high-speed engines with fewer than six cylinders is to use an axial-piston distributor pump, consisting of one rotating pump plunger delivering fuel to a valve and line for each cylinder (functionally analogous to points and distributor cap on an Otto engine). 
  
  
  
  
  Many modern systems have a single fuel pump which supplies fuel constantly at high pressure with a common rail (single fuel line common) to each injector. Each injector has a solenoid operated by an electronic control unit, resulting in more accurate control of injector opening times that depend on other control conditions, such as engine speed and loading, and providing better engine performance and fuel economy.
  
  
  
  
  Both mechanical and electronic injection systems can be used in either direct or indirect injection configurations. Two-stroke diesel engines with mechanical injection pumps can be inadvertently run in reverse, albeit in a very inefficient manner, possibly damaging the engine. Large ship two-stroke d
  iesels are designed to run in either direction, obviating the need for a gearbox.
  
  
  
  
  An indirect injection diesel engine delivers fuel into a chamber off the combustion chamber, called a pre-chamber or ante-chamber, where combustion begins and then spreads into the main combustion chamber, assisted by turbulence created in the chamber. This system allows for a smoother, quieter running engine, and because combustion is assisted by turbulence, injector pressures can be lower, about 100 bar (10 MPa; 1,500 psi), using a single orifice tapered jet injector. Mechanical injection systems allowed high-speed running suitable for road vehicles (typically up to speeds of around 4000 rpm. The pre-chamber had the disadvantage of increasing heat loss to the engine's cooling system, and restricting the combustion burn, which reduced the efficiency by five to ten percent. Indirect injection engines are cheaper to build and it is easier to produce smooth, quiet-running vehicles with a simple mechanical system. In road-going vehicles most prefer the greater efficiency and better-controlled emission levels of direct injection. Indirect injection diesels can still be found in the many ATV diesel applications.
  
  
  
  
  Direct injection diesel engines have injectors mounted at the top of the combustion chamber. The injectors are activated using one of two methods - hydraulic pressure from the fuel pump, or an electronic signal from an engine controller.
  
  
  
  
  Hydraulic pressure activated injectors can produce harsh engine noise. Fuel consumption is about 15 to 20 percent lower than indirect injection diesels. The extra noise is generally not a problem for industrial uses of the engine, but for automotive usage, buyers have to decide whether or n
  ot the increased fuel efficiency would compensate for the extra noise.
  
  
  Electronic control of the fuel injection transformed the direct injection engine by allowing much greater control over the combustion.
  
  
  
  
   Unit direct injection also injects fuel directly into the cylinder of the engine. In this system the injector and the pump are combined into one unit positioned over each cylinder controlled by the camshaft. Each cylinder has its own unit eliminating the high-pressure fuel lines, achieving a more consistent injection. Volkswagen AG uses this type of injection system, also developed by Bosch, in cars (where it is called a Pumpe-Düse-System—literally pump-nozzle system) and by Mercedes Benz ("PLD") and most major diesel engine manufacturers in large commercial engines (CAT, Cummins, Detroit Diesel, Electro-Motive Diesel, Volvo). With recent advancements, the pump pressure has been raised to 2,400 bars (240 MPa; 35,000 psi), allowing injection parameters similar to common rail systems.
  
  
  
  
   In common rail systems, the separate pulsing high-pressure fuel line to each cylinder's injector is also eliminated. Instead, a high-pressure pump pressurizes fuel at up to 2,500 bar (250 MPa; 36,000 psi), in a "common rail". The common rail is a tube that supplies each computer-controlled injector containing a precision-machined nozzle and a plunger driven by a solenoid or piezoelectric actuator.
  
  
  
  
  In cold weather, high-speed diesel engines can be difficult to start because the mass of the cylinder block and cylinder head absorb the heat of compression, preventing ignition due to the higher surface-to-volume ratio. Pre-chambered engines make use of small electric heaters inside the pre-chambers called glowplugs, while the direct-injected engines have these glowplugs in the combustion chamber.
  
  
  
  
  Many engines use resistive heaters in the intake manifold to warm the inlet air for starting, or until the engine reaches operating temperature. Engine block heaters (electric resistive heaters in the engine block) connected to the utility grid are used in cold climates when an engine is turned off for extended periods (more than an hour), to reduce startup time and engine wear. Block heaters are also used for emergency power standby Diesel-powered generators, which must rapidly pick up load on a power failure. In the past, a wider variety of cold-start methods were used. Some engines, such as Detroit Diesel engines used a system to introduce small amounts of ether into the inlet manifold to start combustion. Others used a mixed system, with a resistive heater-burning methanol. An impromptu method, particularly on out-of-tune engines, is to manually spray an aerosol can of ether-based engine starter fluid into the intake air stream (usually through the intake air filter assembly).
  
  
  
  
  Diesel fuel is also prone to waxing or gelling in cold weather; both are terms for the solidification of diesel oil into a partially crystalline state. The crystals build up in the fuel line (especially in fuel filters), eventually starving the engine of fuel and causing it to stop running. Low-output electric heaters in fuel tanks and around fuel lines are used to solve this problem. Also, most engines have a spill return system, by which any excess fuel from the injector pump and injectors is returned to the fuel tank. Once the engine has warmed, returning warm fuel prevents waxing in the tank.
  
  
  
  
  Due to improvements in fuel technology with additives, waxing rarely occurs in all but the coldest weather when a mix of diesel and kerosene may be used to run a vehicle. Gas stations in regions with a cold climate are required to offer winterized diesel in the cold seasons that allow operation below a specific Cold Filter Plugging Point. In Europe these diesel characteristics are described in the EN 590 standard.
  
  
  
  
  Most diesels are now turbocharged and some are both turbocharged and supercharged. Because diesels do not have fuel in the cylinder before combustion is initiated, more than one bar (100 kPa) of air can be loaded in the cylinder without pre-ignition. A turbocharged engine can produce significantly more power than a naturally aspirated engine of the same configuration, as having more air in the cylinders allows more fuel to be burned and thus more power to be produced. A supercharger is powered mechanically by the engine's crankshaft, while the engine exhaust, not requiring any mechanical power, powers a turbocharger. Turbocharging can improve the fuel economy of diesel engines by recovering waste heat from the exhaust, increasing the excess air factor, and increasing the ratio of engine output to friction losses.
  
  
  
  
  A two-stroke engine does not have a discrete exhaust and intake stroke and thus is incapable of self-aspiration. Therefore all two-stroke engines must be fitted with a blower to charge the cylinders with air and assist in dispersing exhaust gases, a process referred to as scavenging. In some cases, the engine may also be fitted with a turbocharger, whose output is directed into the blower inlet. A few designs employ a hybrid turbocharger for scavenging and charging the cylinders, which device is mechanically driven at cranking and low speeds to act as a blower.
  
  
  
  
  As turbocharged or supercharged engines produce more power for a given engine size as compared to naturally aspirated engines, attention must be paid to the mechanical design of components, lubrication, and cooling to handle the power. Pistons are usually cooled with lubrication oil sprayed on the bottom of the piston. Large engines may use water, seawater, or oil supplied through telescoping pipes attached to the crosshead.
  
  
  
  
  As with petrol engines, there are two classes of diesel engines in current use: two-stroke and four-stroke. The four-stroke type is the "classic" version, tracing its lineage back to Rudolf Diesel's prototype. It is also the most commonly used form, being the preferred power source for many motor vehicles, especially buses and trucks. Much larger engines, such as used for railroad locomotion and marine propulsion, are often two-stroke units, offering a more favorable power-to-weight ratio, as well as better fuel economy
  
  
  
  
  Two-stroke diesel engine operation is similar to that of petrol counterparts, except that fuel is not mixed with air before induction, and the crankcase does not take an active role in the cycle. The traditional two-stroke design relies upon a mechanically driven positive displacement blower to charge the cylinders with air before compression and ignition. The charging process also assists in expelling (scavenging) combustion gases remaining from the previous power stroke.
  
  
  
  
  The archetype of the modern form of the two-stroke diesel is the (high-speed) Detroit Diesel Series 71 engine, designed by Charles F. "Boss" Kettering and his colleagues at General Motors Corporation in 1938, in which the blower pressurizes a chamber in the engine block that is often referred to as the "air box". The (very much larger medium-speed) Electro-Motive Diesel engine is used as the prime mover in EMD diesel-electric locomotive, marine and stationary applications, and was designed by the same team, and is built to the same principle. However, a significant improvement built into later EMD engines is the mechanically assisted turbo-compressor, which provides charge air using mechanical assistance during starting (thereby obviating the necessity for Roots-blown scavenging), and provides charge air using an exhaust gas-driven turbine during normal operations—thereby providing true turbocharging and additionally increasing the engine's power output by at least fifty percent. 
  
  
  
  
  In a two-stroke diesel engine, as the cylinder's piston approaches the bottom dead centre exhaust ports or valves are opened relieving most of the excess pressure after which a passage between the air box and the cylinder is opened, permitting air flow into the cylinder. The airflow blows the remaining combustion gases from the cylinder—this is the scavenging process. As the piston passes through bottom center and starts upward, the passage is closed and compression commences, culminating in fuel injection and ignition. Refer to two-stroke diesel engines for more detailed coverage of aspiration types and supercharging of two-stroke diesel engines.
  
  
  
  
  Normally, the number of cylinders is used in multiples of two, although any number of cylinders can be used as long as the load on the crankshaft is counterbalanced to prevent excessive vibration. The inline-six-cylinder design is the most prolific in light- to medium-duty engines, though small V8 and larger inline-four displacement engines are also common. Small-capacity engines (generally considered to be those below five liters in capacity) are generally four- or six-cylinder types, with the four-cylinder being the most common type found in automotive uses. Five-cylinder diesel engines have also been produced, being a compromise between the smooth running of the six-cylinder and the space-efficient dimensions of the four-cylinder. Diesel engines for smaller plant machinery; boats, tractors, generators and pumps may be four-, three- or two-cylinder types, with the single-cylinder diesel engine remaining for light stationary work. Direct reversible two-stroke marine diesels need at least three cylinders for reliable restarting forwards and reverse, while four-stroke diesels need at least six cylinders.
  
  
  
  
  The desire to improve the diesel engine's power-to-weight ratio produced several novel cylinder arrangements to extract more power from a given capacity. The uniflow opposed-piston engine uses two pistons in one cylinder with the combustion cavity in the middle and gas in- and outlets at the ends. This makes a comparatively light, powerful, swiftly running and economic engine suitable for use in aviation. An example is the Junkers Jumo 204/205. The Napier Deltic engine, with three cylinders arranged in a triangular formation, each containing two opposed pistons, the whole engine having three crankshafts, is one of the better known.
  
  
  
  
  Some information for this article obtained from Wikipedia.org.
  
  
  
  
  Recent Recalls:
  
  
  27,933 Ford 2012-2013 Edge vehicles equipped with 2.0L engines.
  The fuel line pulse damper metal housing may crack as a result of an improper manufacturing process. A cracked fuel line pulse damper housing may result in a combination of fuel odor, weepage, or a continuous leak while the fuel system is pressurized. A fuel leak in the presence of an ignition source may result in a fire.
  
  
  
  
  300 Ford 2011-2012 Explorers certain replacement steering gears installed as service parts.
  The affected gears may lock, preventing the driver from being able to steer the vehicle. The inability to steer the vehicle increases the risk of a crash.
  
  
  
  Contact your local dealership for more information and how to proceed.
  
  
  
  
  
  
  
  
  
  
  
  

Ask Joe Mechanic - Diesel Engine Historical Timeline

A Historic Timeline of significant developments pertaining to diesel engines:





1890s

• 1891: Herbert Akroyd Stuart invents the first internal combustion engine to use a pressurized fuel injection system.
• 1892: February 23, Rudolf Diesel obtained a patent (RP 67207) titled "Arbeitsverfahren und Ausführungsart für Verbrennungsmaschinen".
• 1892: Akroyd Stuart builds his first working Diesel engine.
• 1893: Diesel's essay titled Theory and Construction of a Rational Heat-engine to Replace the Steam Engine and Combustion Engines Known Today appeared.
• 1893: August 10, Diesel built his first working prototype in Augsburg.
• 1897: Adolphus Busch licenses rights to the Diesel Engine for the USA and Canada.
• 1899: Diesel licensed his engine to builders Krupp and Sulzer, who quickly became major manufacturers.

1900s

• 1902: Until 1910 MAN produced 82 copies of the stationary diesel engine.
• 1903: Two first diesel-powered ships were launched, both for river and canal operations: Petite-Pierre in France, powered by Dyckhoff-built diesels, and Vandal tanker in Russia, powered by Swedish-built diesels with an electrical transmission.
• 1904: The French built the first diesel submarine, the Z.
• 1905: Four diesel engine turbochargers and intercoolers were manufactured by Büchl (CH), as well as a scroll-type supercharger from Creux (F) company.
• 1908: Prosper L'Orange and Deutz developed a precisely controlled injection pump with a needle injection nozzle.
• 1909: The prechamber with a hemispherical combustion chamber was developed by Prosper L'Orange with Benz.

1910s

• 1910: The Norwegian research ship Fram was a sailing ship fitted with an auxiliary diesel engine, and was thus the first ocean-going ship with a diesel engine.
•  1912: The Danish built the first ocean-going ship exclusively powered by a diesel engine, MS Selandia. The first locomotive with a diesel engine also appeared.
• 1913: U.S. Navy submarines used NELSECO units. Rudolf Diesel died mysteriously when he crossed the English Channel on the SS Dresden.
• 1914: German U-boats were powered by MAN diesels.
• 1919: Prosper L'Orange obtained a patent on a prechamber insert and made a needle injection nozzle. First diesel engine from Cummins.

1920s

• 1922: The first vehicle with a (pre-chamber) diesel engine was Agricultural Tractor Type 6 of the Benz Söhne agricultural tractor OE Benz Sendling.
• 1923: The first truck with pre-chamber diesel engine made by MAN and Benz. Daimler-Motoren-Gesellschaft testing the first air-injection diesel-engined truck.
• 1924: The introduction on the truck market of the diesel engine by commercial truck manufacturers in the IAA. Fairbanks-Morse starts building diesel engines.
• 1927: First truck injection pump and injection nozzles of Bosch. First passenger car prototype of Stoewer.

1930s

• 1930s: Caterpillar started building diesels for their tractors.
• 1930: First US diesel-power passenger car (Cummins powered Packard) built in Columbus, Indiana (USA)
• 1933: First European passenger cars with diesel engines (Citroën Rosalie); Citroën used an engine of the English diesel pioneer Sir Harry Ricardo. The car did not go into production due to legal restrictions on the use of diesel engines.
• 1936: Mercedes-Benz built the 260D diesel car. AT&SF inaugurated the diesel train Super Chief. The airship Hindenburg was powered by diesel engines. First series of passenger cars manufactured with diesel engine (Mercedes-Benz 260 D, Hanomag and Saurer). Daimler Benz airship diesel engine 602LOF6 for the LZ129 Hindenburg airship

1940s

• 1942: Tatra started production of Tatra 111 with air-cooled V12 diesel engine.
• 1943-'46: The Common-rail (CRD) system was invented (and patented by) Clessie Cummins
• 1944: Development of air cooling for diesel engines by Klöckner Humboldt Deutz AG (KHD) for the production stage, and later also for Magirus Deutz.

1950s

• 1953: Turbo-diesel truck for Mercedes in small series.
• 1954: Turbo-diesel truck in mass production by Volvo. First diesel engine with an overhead cam shaft of Daimler Benz.

1960s

• 1960: The diesel drive displaced steam turbines and coal fired steam engines.
• 1962-'65: A diesel compression braking system, eventually to be manufactured by Jacobs (of drill chuck fame) and nicknamed the "Jake Brake", was invented and patented by Clessie Cummins.
•  1968: Peugeot introduced the first 204 small cars with a transversally mounted diesel engine and front-wheel drive.

1970s

• 1973: DAF produced an air-cooled diesel engine.
• 1976 February: Tested a diesel engine for the Volkswagen Golf passenger car. The Cummins Common Rail injection system was further developed by the ETH Zurich from 1976 to 1992.
• 1978: Mercedes produced the first passenger car turbo-diesels (Mercedes 300 SD).
• 1978: Oldsmobile introduced the first passenger car diesel engine produced by an American car company.

1980s

• 1985: ATI Intercooler diesel engine from DAF. European Truck Common Rail system with the IFA truck type W50 introduced.
• 1986: Electronic Diesel Control (EDC) of Bosch with the BMW 524td.
• 1986: The Fiat Croma was the first passenger car in the world to have a direct injection turbodiesel engine in (1986).

1990s

• 1991: European emission standards Euro 1 met with the truck diesel engine of Scania.
• 1994: Unit injector system by Bosch for diesel engines.
• 1995: First successful use of common rail in a production vehicle, by Denso in Japan, Hino "Rising Ranger" truck.
• 1997: First common rail in passenger car, Alfa Romeo 156.
•  1998: BMW made history by winning the 24 Hour Nürburgring race with the 320d, powered by a two-litre, four-cylinder diesel engine. The combination of high-performance with better fuel efficiency allowed the team to make fewer pit stops during the long endurance race.

2000s

• 2002: A street-driven Dodge Dakota pickup with a 735 horsepower (548 kW) diesel engine built at Gale banks engineering hauls its own service trailer to the Bonneville Salt Flats and set an FIA land speed record as the world's fastest pickup truck with a one-way run of 222 mph (357 km/h) and a two-way average of 217 mph (349 km/h).
• 2004: In Western Europe, the proportion of passenger cars with diesel engine exceeded 50%. Selective catalytic reduction (SCR) system in Mercedes, Euro 4 with EGR system and particle filters of MAN. Piezoelectric injector technology by Bosch.
• 2006: Audi R10 TDI won 12 hours running in Sebring and defeated all other engine concepts. The same car won the 2006 24 Hours of Le Mans.
• 2006: JCB Dieselmax broke the FIA Diesel Land speed record from 1973, eventually setting the new record at over 350 mph (563 km/h).
• 2008: Subaru introduced the first horizontally opposed diesel engine to be fitted to a passenger car. This is a Euro 5 compliant engine with an EGR system.
• 2009: Volkswagen won the 2009 Dakar Rally held in Argentina and Chile. The first diesel to do so. Race Touareg 2 finished 1st and 2nd.

2010s

• 2010: Mitsubishi developed and started mass production of its 4N13 1.8 L DOHC I4, the world's first passenger car diesel engine that features a variable valve timing system.

Next week; How diesel engines work, types of diesel engines and if space permits, advantages and disadvantages of diesel engines.

Some information obtained from Wikipedia.org.

Ask Joe Mechanic - Diesel Engine Vehicles (Part 1)

After covering hybrid and electric powered vehicles for the previous several weeks, I am now going to spend several weeks discussing diesel-powered vehicles. I will demonstrate their history, how they work, types, inherent advantages and disadvantages, why they are so efficient, safety, recent and future innovations.  Also we will discuss the comparisons of diesel use throughout the world as compared to the USA, and why the disparity exists.

A diesel engine (also known as a compression-ignition engine) is an internal combustion engine that uses the heat of compression to initiate ignition and burn the fuel that has been injected into the combustion chamber. This contrasts with spark-ignition engines such as a gasoline engine or gas engine (using a gaseous fuel as opposed to gasoline), which use a spark plug to ignite an air-fuel mixture. The diesel engine has the highest thermal efficiency of any standard internal or external combustion engine due to its very high compression ratio.

Diesel engines are manufactured in two-stroke and four-stroke versions. They were originally used as a more efficient replacement for stationary steam engines. Since the 1910s they have been used in submarines and ships. Use in locomotives, trucks, heavy equipment and electric generating plants followed later. In the 1930s, they slowly began to be used in a few automobiles. 

According to the British Society of Motor Manufacturing and Traders, the EU average for diesel cars account for 50 percent of the total diesel powered vehicles sold, including 70 percent in France and 38 percent in the UK. 

In 1885, the English inventor Herbert Akroyd Stuart began investigating the possibility of using paraffin oil (very similar to modern-day diesel) for an engine, which unlike petrol would be difficult to be vaporized in a carburetor as its volatility is not sufficient to allow this. 

His engines, built from 1891 by Richard Hornsby and Sons, were the first internal combustion engines, to use a pressurized fuel injection system. The Hornsby-Akroyd engine used a comparatively low compression ratio, so that the temperature of the air compressed in the combustion chamber at the end of the compression stroke was not high enough to initiate combustion. Combustion instead took place in a separated combustion chamber, the "vaporizer" (also called the "hot bulb") mounted on the cylinder head, into which fuel was sprayed. Self-ignition occurred from contact between the fuel-air mixture and the hot walls of the vaporizer. As the engine's load increased, so did the temperature of the bulb, causing the ignition period to advance; to counteract pre-ignition, water was dripped into the air intake. 

The modern diesel engine incorporates the features of direct (airless) injection and compression-ignition. Akroyd Stuart and Charles Richard Binney patented both of these ideas in May 1890. Another patent was taken out on 8 October 1890, detailing the working of a complete engine - essentially that of a diesel engine - where air and fuel are introduced separately. The difference between the Akroyd engine and the modern diesel engine was the requirement to supply extra heat to the cylinder to start the engine from cold. By 1892, Akroyd Stuart had produced an updated version of the engine that no longer required the additional heat source, a year before diesel's engine.

            In 1892, Akroyd Stuart patented a water-jacketed vaporizer to allow compression ratios to be increased. In the same year, Thomas Henry Barton at Hornsbys built a working high-compression version for experimental purposes, whereby the vaporizer was replaced with a cylinder head, therefore not relying on air being preheated, but by combustion through higher compression ratios. It ran for six hours - the first time automatic ignition was produced by compression alone. This was five years before Rudolf Diesel built his well-known high-compression prototype engine in 1897.

Rudolf Diesel was, however, subsequently credited with the innovation, and he was able to improve the engine further, whereas Akroyd Stuart stopped development on his engine in 1893.

In 1892, he received patents in Germany, Switzerland, the United Kingdom and the United States for "Method of and Apparatus for Converting Heat into Work". In 1893, he described a "slow-combustion engine" that first compressed air thereby raising its temperature above the igniting-point of the fuel, then gradually introducing fuel while letting the mixture expand "against resistance sufficiently to prevent an essential increase of temperature and pressure", then cutting off fuel and "expanding without transfer of heat”. In 1894 and 1895 he filed patents and addenda in various countries for his Diesel engine; the first patents were issued in Spain (No. 16,654), France (No. 243,531) and Belgium (No. 113,139) in December 1894, and in Germany (No. 86,633) in 1895 and the United States (No. 608,845) in 1898. He operated his first successful engine in 1897.

At Augsburg, on August 10, 1893, Rudolf Diesel's prime model, a single 10-foot (3.0 m) iron cylinder with a flywheel at its base, ran on its own power for the first time. Diesel spent two more years making improvements and in 1896 demonstrated another model with a theoretical efficiency of 75 percent, in contrast to the 10 percent efficiency of the steam engine. By 1898, Diesel had become a millionaire. His engines were used to power pipelines, electric and water plants, automobiles and trucks, and marine craft. They were soon to be used in mines, oil fields, factories, and transoceanic shipping.