Cylinder block

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A modern straight-six engine block for a passenger car, integrating the crankcase and all cylinders. The cylinder head bolts to the deck surface at top. Many ribs and bosses can be seen on the side of the casting, as well as the passages for cooling fluid opening into the deck. CarterBMW1.JPG
A modern straight-six engine block for a passenger car, integrating the crankcase and all cylinders. The cylinder head bolts to the deck surface at top. Many ribs and bosses can be seen on the side of the casting, as well as the passages for cooling fluid opening into the deck.
A V6 diesel engine block, with both of the cylinder banks as well as the crankcase formed en bloc. The large holes are the cylinders, while the small ones are the mounting holes (round) and coolant or oil ducts (oval). Cylinder block for V6 Diesel.jpg
A V6 diesel engine block, with both of the cylinder banks as well as the crankcase formed en bloc. The large holes are the cylinders, while the small ones are the mounting holes (round) and coolant or oil ducts (oval).
De Dion-Bouton engine with discrete crankcase but with monobloc integration of the cylinders and heads, circa 1905. A discrete crankcase with upper and lower halves (each its own casting) can clearly be seen, with the bottom half constituting both part of the main bearing support and also an oil sump. De Dion-Bouton engine (Rankin Kennedy, Modern Engines, Vol III).jpg
De Dion-Bouton engine with discrete crankcase but with monobloc integration of the cylinders and heads, circa 1905. A discrete crankcase with upper and lower halves (each its own casting) can clearly be seen, with the bottom half constituting both part of the main bearing support and also an oil sump.

The cylinder block is an integrated structure comprising the cylinder(s) of a reciprocating engine and often some or all of their associated surrounding structures (coolant passages, intake and exhaust passages and ports, and crankcase). The term engine block is often used synonymously with "cylinder block" (although technically distinctions can be made between en bloc cylinders as a discrete unit versus engine block designs with yet more integration that comprise the crankcase as well).

Cylinder (engine) central working part of a reciprocating engine or pump, the space in which a piston travels, often equipped with a cylinder liner

A cylinder is the central working part of a reciprocating engine or pump, the space in which a piston travels. Multiple cylinders are commonly arranged side by side in a bank, or engine block, which is typically cast from aluminum or cast iron before receiving precision machine work. Cylinders may be sleeved or sleeveless. A sleeveless engine may also be referred to as a "parent-bore engine".

Reciprocating engine heat engine that uses one or more reciprocating pistons to convert pressure into a rotating motion

A reciprocating engine, also often known as a piston engine, is typically a heat engine that uses one or more reciprocating pistons to convert pressure into a rotating motion. This article describes the common features of all types. The main types are: the internal combustion engine, used extensively in motor vehicles; the steam engine, the mainstay of the Industrial Revolution; and the niche application Stirling engine. Internal combustion engines are further classified in two ways: either a spark-ignition (SI) engine, where the spark plug initiates the combustion; or a compression-ignition (CI) engine, where the air within the cylinder is compressed, thus heating it, so that the heated air ignites fuel that is injected then or earlier.

Antifreeze coolant additive which reduces the freezing point of water

An antifreeze is an additive which lowers the freezing point of a water-based liquid and increases its boiling point. An antifreeze mixture is used to achieve freezing-point depression for cold environments and also achieves boiling-point elevation ("anti-boil") to allow higher coolant temperature. Freezing and boiling points are colligative properties of a solution, which depend on the concentration of the dissolved substance.

Contents

In the basic terms of machine elements, the various main parts of an engine (such as cylinder(s), cylinder head(s), coolant passages, intake and exhaust passages, and crankcase) are conceptually distinct, and these items can all be made as discrete pieces that are bolted together. Such construction was very widespread in the early decades of the commercialization of internal combustion engines (1880s to 1920s), and it is still sometimes used in certain applications where it remains advantageous (especially very large engines, but also some small engines). However, it is no longer the normal way of building most petrol engines and diesel engines, because for any given engine configuration, there are more efficient ways of designing for manufacture (and also for maintenance and repair). These generally involve integrating multiple machine elements into one discrete part, and doing the making (such as casting, stamping, and machining) for multiple elements in one setup with one machine coordinate system (of a machine tool or other piece of manufacturing machinery). This yields lower unit cost of production (and/or maintenance and repair).

Machine element refers to an elementary component of a machine. These elements consist of three basic types:

  1. structural components such as frame members, bearings, axles, splines, fasteners, seals, and lubricants,
  2. mechanisms that control movement in various ways such as gear trains, belt or chain drives, linkages, cam and follower systems, including brakes and clutches, and
  3. control components such as buttons, switches, indicators, sensors, actuators and computer controllers.
Cylinder head component of a cylinder of an internal combustion engine

In an internal combustion engine, the cylinder head sits above the cylinders on top of the cylinder block. It closes in the top of the cylinder, forming the combustion chamber. This joint is sealed by a head gasket. In most engines, the head also provides space for the passages that feed air and fuel to the cylinder, and that allow the exhaust to escape. The head can also be a place to mount the valves, spark plugs, and fuel injectors.

Bolted joint type of fastener

Bolted joints are one of the most common elements in construction and machine design. They consist of fasteners that capture and join other parts, and are secured with the mating of screw threads.

Today most engines for cars, trucks, buses, tractors, and so on are built with fairly highly integrated design, so the words "monobloc" and "en bloc" are seldom used in describing them; such construction is often implicit. Thus "engine block", "cylinder block", or simply "block" are the terms likely to be heard in the garage or on the street.

Truck type of large automobile

A truck or lorry is a motor vehicle designed to transport cargo. Trucks vary greatly in size, power, and configuration; smaller varieties may be mechanically similar to some automobiles. Commercial trucks can be very large and powerful, and may be configured to mount specialized equipment, such as in the case of fire trucks, concrete mixers, and suction excavators.

Bus large road vehicle for transporting people

A bus is a road vehicle designed to carry many passengers. Buses can have a capacity as high as 300 passengers. The most common type of bus is the single-deck rigid bus, with larger loads carried by double-decker and articulated buses, and smaller loads carried by midibuses and minibuses; coaches are used for longer-distance services. Many types of buses, such as city transit buses and inter-city coaches, charge a fare. Other types, such as elementary or secondary school buses or shuttle buses within a post-secondary education campus do not charge a fare. In many jurisdictions, bus drivers require a special licence above and beyond a regular driver's licence.

Tractor engineering vehicle specifically designed to deliver a high tractive effort

A tractor is an engineering vehicle specifically designed to deliver a high tractive effort at slow speeds, for the purposes of hauling a trailer or machinery used in agriculture or construction. Most commonly, the term is used to describe a farm vehicle that provides the power and traction to mechanize agricultural tasks, especially tillage, but nowadays a great variety of tasks. Agricultural implements may be towed behind or mounted on the tractor, and the tractor may also provide a source of power if the implement is mechanised.

Development context

The move from extensive use of discrete elements (via separate castings) to extensive integration of elements (such as in most modern engine blocks) was a gradual progression that passed through various phases of monobloc engine development, wherein certain elements were integrated while others remained discrete. This evolution has occurred throughout the history of reciprocating engines, with various instances of every conceptual variation coexisting here and there. The increase in prevalence of ever-more-integrated designs relied on the gradual development of foundry and machining practice for mass production. For example, a practical low-cost V8 engine was not feasible until Ford developed the techniques used to build the Ford flathead V8 engine, which soon also disseminated to the larger society. Today the foundry and machining processes for manufacturing engines are usually highly automated, with a few skilled workers to manage the making of thousands of parts.

Monobloc engine

A monobloc or en bloc engine is an internal-combustion piston engine where some of the major components are formed, usually by casting, as a single integral unit, rather than being assembled later. This has the advantages of improving mechanical stiffness, and also improving the reliability of the sealing between them.

Foundry factory that produces metal castings

A foundry is a factory that produces metal castings. Metals are cast into shapes by melting them into a liquid, pouring the metal into a mold, and removing the mold material after the metal has solidified as it cools. The most common metals processed are aluminium and cast iron. However, other metals, such as bronze, brass, steel, magnesium, and zinc, are also used to produce castings in foundries. In this process, parts of desired shapes and sizes can be formed.

Machining process in which a piece of raw material is cut into a desired final shape and size by a controlled material-removal process; manufacturing process

Machining is any of various processes in which a piece of raw material is cut into a desired final shape and size by a controlled material-removal process. The processes that have this common theme, controlled material removal, are today collectively known as subtractive manufacturing, in distinction from processes of controlled material addition, which are known as additive manufacturing. Exactly what the "controlled" part of the definition implies can vary, but it almost always implies the use of machine tools.

Cylinders integrated into one or several cylinder blocks

Cylinders are cast in three pairs Wolseley 6-cylinder marine oil engine (Rankin Kennedy, Modern Engines, Vol V).jpg
Cylinders are cast in three pairs
Cylinders are cast in two blocks of three Six cylinder engine with three cylinder blocks (Autocar Handbook, Ninth edition).jpg
Cylinders are cast in two blocks of three
DB 605 inverted aircraft engine of WW2, with monobloc cylinder blocks and heads Daimler DB 605 cutaway.jpg
DB 605 inverted aircraft engine of WW2, with monobloc cylinder blocks and heads

A cylinder block is a unit comprising several cylinders (including their cylinder walls, coolant passages, cylinder sleeves if any, and so forth). In the earliest decades of internal combustion engine development, monobloc cylinder construction was rare; cylinders were usually cast individually. Combining their castings into pairs or triples was an early win of monobloc design.

Each cylinder bank of a V engine (that is, each side of the V) typically comprised one or several cylinder blocks until the 1930s, when mass production methods were developed that allowed the modern form factor of having both banks plus the crankcase entirely integrated.

V engine internal combustion engine with two banks of cylinders at an angle resembling a V

A V engine, or Vee engine is a common configuration for an internal combustion engine. The cylinders and pistons are aligned, in two separate planes or 'banks', so that they appear to be in a "V" when viewed along the axis of the crankshaft. The Vee configuration generally reduces the overall engine length, height and weight compared with an equivalent inline configuration.

A wet liner cylinder block features cylinder walls that are entirely removable, which fit into the block by means of special gaskets. They are referred to as "wet liners" because their outer sides come in direct contact with the engine's coolant. In other words, the liner is the entire wall, rather than being merely a sleeve. Advantages are that the coolant liquid is heated quicker from a cold start reducing fuel enrichments times giving improved fuel consumption and quicker car heater warm ups. Others are less weight and bulk. Wet liner designs are popular with European manufacturers, most notably Renault and Peugeot, who continue to use them to the present. Dry liner designs use either the block's material or a discrete liner inserted into the block to form the backbone of the cylinder wall. Additional sleeves are inserted within, which remain "dry" on their outside, surrounded by the block's material. With either wet or dry liner designs, the liners (or sleeves) can be replaced, potentially allowing overhaul or rebuild without replacement of the block itself; but in reality, they are difficult to remove and install, and for many applications (such as most late-model cars and trucks), an engine will never undergo such a procedure in its working lifespan. It is likelier to be scrapped, with new equipment—engine or entire vehicle—replacing it.

Renault automotive brand manufacturer and conglomerate

Groupe Renault is a French multinational automobile manufacturer established in 1899. The company produces a range of cars and vans, and in the past has manufactured trucks, tractors, tanks, buses/coaches and autorail vehicles.

Peugeot French automotive brand manufacturing subsidiary of Groupe PSA

Peugeot is a French automotive manufacturer, part of Groupe PSA.

Cylinder blocks and crankcase integrated

A flathead engine with integral cylinder bank and crankcase. The head is tipped upward to reveal the deck. This example is typical of engines of the 1930s through 1950s. Cylinder block and head of sidevalve engine (Autocar Handbook, Ninth edition).jpg
A flathead engine with integral cylinder bank and crankcase. The head is tipped upward to reveal the deck. This example is typical of engines of the 1930s through 1950s.

Casting technology at the dawn of the internal combustion engine could reliably cast either large castings, or castings with complex internal cores to allow for water jackets, but not both simultaneously. Most early engines, particularly those with more than four cylinders, had their cylinders cast as pairs or triplets of cylinders, then bolted to a single crankcase.

As casting techniques improved, an entire cylinder block of 4, 6, or 8 cylinders could be cast as one. This was a simpler construction, thus less expensive (unit-wise) to make. For straight engines, this meant that one engine block could now comprise all the cylinders plus the crankcase. Monobloc straight fours, uncommon when the Ford Model T was introduced with one in 1908, became common during the next decade, and monobloc straight sixes followed soon after. By the mid-1920s, both were common, and the straight sixes of General Motors (along with other features that differentiated GM's various makes and models from the Model T) were prying market share away from Ford. (These were all flathead designs.) During that decade, V engines retained a separate block casting for each cylinder bank, with both bolted onto a common crankcase (itself a separate casting). For economy, some engines were designed to use identical castings for each bank, left and right. [2] The complex ducting required for intake and exhaust was too complicated to allow the integration of the banks, except on a few rare engines, such as the Lancia 22½° narrow-angle V12 of 1919, that did manage to use a single block casting for both banks. [3] The hurdles of integrating the banks of the V for common, affordable cars were first overcome by the Ford Motor Company with its Ford flathead V-8, introduced in 1932, which was the first V-8 with a single engine block casting, putting an affordable V-8 into an affordable car for the first time. [4]

The communal water jacket of monobloc designs permitted closer spacing between cylinders. The monobloc design also improved the mechanical stiffness of the engine against bending and the increasingly important torsional twist, as cylinder numbers, engine lengths, and power ratings increased.

Most engines made today, except some unusual V or radial engines, are a monobloc of crankcase and all cylinders. In such cases, the skirts of the cylinder banks form a crankcase area of sorts, which is still often called a crankcase despite no longer being a discrete part.

Engine blocks are normally cast from either a suitable grade of iron or an aluminium alloy. The aluminium block is much lighter in weight, and has better heat transfer to the coolant, but iron blocks retain some advantages and continue to be used by some manufacturers. Use of steel cylinder liners and bearing shells minimizes the effect of the relative softness of aluminium. Some engine designs use plasma transferred wire arc thermal spraying instead cylinder sleeves, to reduce weight. They can also be produced in compacted graphite iron (CGI) such as some diesel engines from Navistar International. [5]

Combined block, head, and crankcase

Light-duty consumer-grade Honda GC-family small engines use a monobloc design where the cylinder head, block, and half the crankcase share the same casting, termed 'uniblock' by Honda. [6] One reason for this, apart from cost, is to produce an overall lower engine height. Being an air-cooled OHC design, this is possible thanks to current aluminum casting techniques and lack of complex hollow spaces for liquid cooling. The valves are vertical, which permits assembly in this confined space. On the other hand, performing basic repairs becomes so time-consuming that the engine can be considered disposable. Commercial-duty Honda GX-family engines (and their many popular knock-offs) have a more conventional design of a single crankcase and cylinder casting, with a separate cylinder head.

Honda produces many other head-block-crankcase monoblocs under several names, such as the GXV-series. They may all be externally identified by a gasket which would bisect the crankshaft on an approximately 45° angle.

Exhaust valve failure is common and, owing to the monobloc design, so labour-intensive to repair that the engine is normally discarded.

Engine block, transmission case, and rear axle housing as frame members

Many farm tractor designs have incorporated their engine block, transmission case, and rear axle housing as frame members. Probably the first was the Fordson tractor, but many others followed. As with many other instances of integration of components into fewer castings, lower unit cost of production was the driver.

An engine block repair shop Engine Block Repair Shop.jpg
An engine block repair shop

See also

Related Research Articles

Sleeve valve

The sleeve valve is a type of valve mechanism for piston engines, distinct from the usual poppet valve. Sleeve valve engines saw use in a number of pre-World War II luxury cars and in the United States in the Willys-Knight car and light truck. They subsequently fell from use due to advances in poppet-valve technology, including sodium cooling, and the Knight system double sleeve engine's tendency to burn a lot of lubricating oil or to seize due to lack of it. The Scottish Argyll company used its own, much simpler and more efficient, single sleeve system (Burt-McCollum) in its cars, a system which, after extensive development, saw substantial use in British aircraft engines of the 1940s, such as the Napier Sabre, Bristol Hercules, Centaurus, and the promising but never mass-produced Rolls-Royce Crecy, only to be supplanted by the jet engines.

Cylinder bank term for a number of cylinders in an engine block

Internal combustion piston engines are usually arranged so that the cylinders are in lines parallel to the crankshaft. Where they are in a single line, this is referred to as an inline or straight engine.

Straight engine engine configuration

The straight or inline engine is an internal-combustion engine with all cylinders aligned in one row and having no offset. Usually found in four, six and eight cylinder configurations, they have been used in automobiles, locomotives and aircraft, although the term in-line has a broader meaning when applied to aircraft engines, see Inline engine (aviation).

Engine configuration is an engineering term for the layout of the major components of a reciprocating piston internal combustion engine. These components are the cylinders and crankshafts in particular but also, sometimes, the camshaft(s).

Ford 335 engine

The Ford 335 engine family was a group of engines built by the Ford Motor Company between 1969 and 1982. The "335" designation reflected Ford management's decision to produce an engine of that size with room for expansion during its development. This engine family began production in late 1969 with a 351 cu in (5.8 L) engine, commonly called the 351C. It later expanded to include a 400 cu in (6.6 L) engine which used a taller version of the engine block, commonly referred to as a tall deck engine block, a 351 cu in (5.8 L) tall deck variant, called the 351M, and a 302 cu in (4.9 L) engine which was exclusive to Australia.

Ford Windsor engine

The Ford Small Block is a series of automobile V8 engines built by the Ford Motor Company beginning in July 1961. The engine was discontinued in new trucks (F-Series) after 1996, and new SUVs (Explorer) after 2001, but remains available for purchase from Ford Racing and Performance Parts as a crate engine. The "Windsor" designation is a retroactive applied for the family of engines sharing a common basic engine block design. The Windsor designation was adopted to distinguish the 351 cu in (5.8 L) version from the Cleveland 335-family engine that had the same displacement, but a significantly different configuration. The designations of 'Windsor' and 'Cleveland' were derived from the locations of manufacture: Windsor, Ontario and Cleveland, Ohio.

Ford flathead V8 engine

The Ford flathead V8 is a V8 engine of the valve-in-block type designed by the Ford Motor Company and built by Ford and various licensees. During the engine's first decade of production, when overhead-valve engines were rare, it was usually known simply as the Ford V‑8, and the first car model in which it was installed, the Model 18, was often called simply the "Ford V‑8", after its new engine. Although the V8 configuration was not new when the Ford V8 was introduced in 1932, the latter was a market first in the respect that it made an 8-cylinder affordable and a V engine affordable to the emerging mass market consumer for the first time. It was the first independently designed and built V8 engine produced by Ford for mass production, and it ranks as one of the company's most important developments. A fascination with ever-more-powerful engines was perhaps the most salient aspect of the American car and truck market for a half century, from 1923 until 1973. The engine was intended to be used for big passenger cars and trucks; it was installed in such until 1953, making the engine's 21-year production run for the U.S. consumer market longer than the 19-year run of the Ford Model T engine for that market. The engine was on Ward's list of the 10 best engines of the 20th century. It was a staple of hot rodders in the 1950s, and it remains famous in the classic car hobbies even today, despite the huge variety of other popular V8s that followed.

Crankcase

A crankcase is the housing for the crankshaft in a reciprocating internal combustion engine. The enclosure forms the largest cavity in the engine and is located below the cylinder(s), which in a multicylinder engine is usually integrated into one or several cylinder blocks. Crankcases have often been discrete parts, but more often they are integral with the cylinder bank(s), forming an engine block. Nevertheless, the area around the crankshaft is still usually called the crankcase. Crankcases and other basic engine structural components are typically made of cast iron or cast aluminium via sand casting. Today the foundry processes are usually highly automated, with a few skilled workers to manage the casting of thousands of parts.

Wasserboxer

The Volkswagen wasserboxer is a four cylinder horizontally opposed pushrod overhead-valve (OHV) petrol engine developed by Volkswagen. The engine is water-cooled, and takes its name from the German: "wasserboxer" ("Water-boxer"); with "boxer" being another term for horizontally opposed engines. It was available in two displacements - either a 1.9-litre or a 2.1-litre; the 2.1-litre being a longer stroke version of the 1.9-litre, both variants sharing the same cylinder bore. This engine was unique to the Volkswagen Type 2 (T3), having never been used in any other vehicle. Volkswagen contracted Oettinger to develop a six-cylinder version of this engine. Volkswagen decided not to use it, but Oettinger sold a Volkswagen Type 2 (T3) equipped with this engine.

The Paxman Ventura is a diesel engine for railway locomotives, built by Davey, Paxman & Co.

Junk head

A junk head is a form of piston engine cylinder head, where the head is formed by a dummy piston mounted inside the top of the cylinder. In most other engine designs, the cylinder head is mounted on top of the cylinder block. That form has also been termed a "poultice head".

Standard wet liner inline-four engine

The Standard wet liner inline-four engine was a 2,088 cc inline four cylinder petrol engine produced by the Standard Motor Company. Originally developed for the Ferguson TE20 tractor, it was widely used for Standard passenger cars of the 1950s, most notably the Vanguard. Later it was successfully used in Standard's popular early generation Triumph TR series sports cars.

A long-bolt or through-bolt engine is an internal combustion piston engine where, following usual practice, the cylinder head is held down by bolts or studs. Conventionally the cylinder head is bolted to the cylinder block and the crankshaft main bearings are in turn bolted to the crankcase by separate bolts. In the long-bolt engine however, a single set of long bolts is used, spanning from the cylinder head right through to the crankshaft bearing caps.

The term power assembly refers to an Electro-Motive Diesel (EMD) engine sub-assembly designed to be "easily" removed and replaced in order to restore engine performance lost to wear or engine failure. Typical of heavy-duty internal combustion engines used in industrial applications, EMD engines are designed to allow the cylinder liners, pistons, piston rings and connecting rods to be replaced at overhaul without removing the entire engine assembly from its application location. This increases engine value, reduces downtime and allows the engine to be returned to true new engine performance. Other terms such as cylinder pack, liner pack, cylinder assembly and cylinder kit are used in the engine industry to describe similar assemblies. In the large-engine industry, the term "power assembly" has also become generic and is often used to refer to the assemblies used in non-EMD engines where "power pack" may be the preferred term, although both terms are functionally the same.

Internal combustion engine engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber

An internal combustion engine (ICE) is a heat engine where the combustion of a fuel occurs with an oxidizer in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combustion engine, the expansion of the high-temperature and high-pressure gases produced by combustion applies direct force to some component of the engine. The force is applied typically to pistons, turbine blades, rotor or a nozzle. This force moves the component over a distance, transforming chemical energy into useful mechanical energy.

The Fiat Pratola Serra modular engines are a family of engines produced by the Fiat Group since 1994 and used in Fiat, Alfa Romeo, Lancia and Jeep vehicles. They are named after the Pratola Serra municipality in which they're being produced.

Mercedes-Benz OM629 engine motorcar diesel engine

The Mercedes-Benz OM629 is a 4.0 litres (3,996 cc) diesel-fuelled, 4-stroke, compression-ignition internal combustion 75° 32-valve V8 engine used in the 2000s. It is the world’s first aluminium V8 diesel engine.

References

  1. ↑ Kennedy, Rankin. The De Dion-Bouton Engine and Cars (1912 edition of 1905 book). The Book of Modern Engines and Power Generators. London: Caxton. pp. 78–89.
  2. ↑ Ludvigsen, V12 Engine, p. 120
  3. ↑ Ludvigsen, V12 Engine, p. 50-53
  4. ↑ Sorensen 1956 , pp. 225–231.
  5. ↑ Brooks, Robert (January 25, 2012). "Navistar Now Producing Engine Blocks, Heads in CGI". Foundry Management & Technology. Retrieved May 2, 2017.
  6. ↑ "Honda General Purpose Engines: GC Series - Single Cylinder". Archived from the original on 2010-11-27. Includes sectioned drawings

Bibliography

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