The BMW M30 is a SOHC straight-six petrol engine, produced from 1968 to 1992. With a production run of 22 years, it is BMW's longest produced engine and was used in many car models; the first models to use the M30 engine were 2800 sedans. The initial M30 models were produced in displacements of 2,494–2,986 cc, with versions having displacements of up to 3,430 cc; as per the BMW M10 four-cylinder engine from which the M30 was developed, the M30 has an iron block, an aluminium head and an overhead camshaft with two valves per cylinder. The engine was given the nicknames of'Big Six' and'Senior Six', following the introduction of the smaller BMW M20 straight-six engine in the late 1970s; the M30 was produced alongside the M20 throughout the M20's production, prior to the introduction of the BMW M70 V12 engine in 1987, the M30 was BMW's most powerful and largest regular production engine. Following the introduction of the BMW M50 engine in 1990, the M30 began to be phased out. Ward's have rated the M30 as one of the "Top Engines of the 20th Century".
The M30 was developed in the late 1960s, loosely based on the BMW M10 four-cylinder engine first used in the BMW New Class sedans and coupes. The engine code was "M06", until it was renamed the M30. Common features between the M10 and M30 include a profile lowering 30-degree slant to the right, a crossflow cylinder head and chain-driven camshaft with rocker arm valve actuation. Further similarities include a cast-iron block with a forged crankshaft; the first two M30 engines introduced were the 2,788 cc and the 2,494 cc versions, which both used an 86 mm bore. The M90 engine, used in several models from 1979-1982, combines the block from the motorsports BMW M88 DOHC engine with the M30's SOHC cylinder head; the first 2,494 cc version of the M30 was introduced in the 1968 E3 2500. This version uses dual Solex Zenith 35/40 INAT carburettors, has a compression ratio of 9.0:1 and produces 110 kW in most applications. It has a stroke of 86 mm × 71.6 mm. The M30B25 has been called the M06 and M68, prior to BMW retroactively renaming it the M30B25V.
Applications: 1968–1977 E3 2500 1974–1975 E9 2.5 CS 1973–1976 E12 525 — 107 kW, Solex 4A1 carburettor 1976–1981 E12 525 1977–1979 E23 725 In 1981, Bosch L-Jetronic electronic fuel injection was added to the 2,494 cc version. Peak power remained unchanged at 110 kW, however torque increased to 215 N⋅m. Applications: 1981-1987 E28 525i 1981-1986 E23 725i The M30B28V version produces up to 125 kW and 235 N⋅m, depending on the model year and country, it has a compression ratio of 9.0:1 and used dual Zenith 35/40 INAT carburettors. The bore is 86 mm and the stroke is 86 mm × 80 mm; this version has been known as the M06 and M68, prior to BMW renaming it the M30B28V. Applications: 1968-1977 E3 2800 / 2.8L — 125 kW 1968-1971 E9 2800 CS 1971-1971 E3 Bavaria — United States only 1974-1976 E12 528 — 121 kW, dual Zenith INAT carburettors 1976-1978 E12 528 — 125 kW, Solex 4A1 carburettor 1977-1979 E23 728 — 125 kW, Solex 4A1 carburettor In 1977, Bosch L-Jetronic electronic fuel injection was added to the 2,788 cc version.
Power increased to torque increased to 240 N ⋅ m. 1977-1978 E12 528i — North America only, 129 kW, 9.0:1 compression ratio 1978-1981 E12 528i 1979-1986 E23 728i 1979-1987 E24 628CSi 1981-1987 E28 528i Based on the M30B28V version with a 3 mm larger bore, the M30B30V produces 132 kW and 255 N⋅m, uses dual Zenith 35/40 INAT carburettors and has a compression ratio of 9.0:1. Applications: 1971-1975 E9 3.0 CS 1971-1972 E9 3.0 CSL 1971-1974 E3 3.0 S / 3.0 L / Bavaria 1976-1979 E24 630 CS — 136 kW, Pierburg 4A1 carburetor 1977-1979 E23 730 — 135 kW, Solex 4 A 1 carburettor The fuel injected version of the 2,986 cc M30 debuted in 1971 in the E9 3.0 CSi and used the Bosch D-Jetronic mechanical fuel injection system. In 1976, the fuel injection system was upgraded to Bosch L-Jetronic electronic fuel injection; the M30B30 produces up to 149 kW and 272 N⋅m, depending on the model year and whether a catalytic converter is fitted. The compression ratio is 9.5:1. Applications: 1971-1975 E9 3.0 CSi — 149 kW 1972-1973 E9 3.0 CSL — 149 kW 1972-1975 E3 3.0 Si — 147 kW 1975-1978 E12 530i — North America only, 131 kW 1976-1976 E12 530 MLE — South Africa only, 147 kW 1977-1978 E24 630CSi — North America only, 129 kW 1986-1992 E32 730i — 138 kW 1988-1990 E34 530i — 138 kW Despite having a capacity of 3,210 cc, this engine appeared in many cars badged so as to suggest 3.3 L of displacement- such as the 633i, 3.3 Li, 733i.
The compression ratio is 8.8:1. In the E24 633CSi coupe, the M30B32 uses Bosch L-Jetronic electronic fuel injection; the US version used L-Jetronic from 1978 until mid-1981, changing over to Motronic digital fuel injection in June of that year. The 1979 732i is BMW's first use of Bosch's Motronic fuel injection; the bore is 89 mm and the stroke is 86 mm. Applications: 1973-1975 E9 3.0 CSL — 152 kW, 3,153 cc 1976-1984 E24 633CSi — 145–147 kW in Euro spec, 128–130 kW in USA spec 1976-1979 E3 3.3 Li — 147 kW 1977-1984 E23 733i — 147 kW in Euro spec, 130–145 kW in U
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; this joint is sealed by a head gasket. In most engines, the head provides space for the passages that feed air and fuel to the cylinder, that allow the exhaust to escape; the head can be a place to mount the valves, spark plugs, fuel injectors. In a flathead or sidevalve engine, the mechanical parts of the valve train are all contained within the block, a'poultice head' may be used, a simple metal plate bolted to the top of the block. Keeping all moving parts within the block has an advantage for physically large engines in that the camshaft drive gear is small and so suffers less from the effects of thermal expansion in the cylinder block. With a chain drive to an overhead camshaft, the extra length of chain needed for an overhead cam design could give trouble from wear and slop in the chain without frequent maintenance. Early sidevalve engines were in use at a time of simple fuel chemistry, low octane ratings and so required low compression ratios.
This made their combustion chamber design less critical and there was less need to design their ports and airflow carefully. One difficulty experienced at this time was that the low compression ratio implied a low expansion ratio during the power stroke. Exhaust gases were thus still hot, hotter than a contemporary engine, this led to frequent trouble with burnt exhaust valves. A major improvement to the sidevalve engine was the advent of Ricardo's turbulent head design; this reduced the space within the combustion chamber and the ports, but by careful thought about the airflow paths within them it allowed a more efficient flow in and out of the chamber. Most it used turbulence within the chamber to mix the fuel and air mixture. This, of itself, allowed the use of higher compression ratios and more efficient engine operation; the limit on sidevalve performance is not the gas flow through the valves, but rather the shape of the combustion chamber. With high speed engines and high compression, the limiting difficulty becomes that of achieving complete and efficient combustion, whilst avoiding the problems of unwanted pre-detonation.
The shape of a sidevalve combustion chamber, being wider than the cylinder to reach the valve ports, conflicts with achieving both an ideal shape for combustion and the small volume needed for high compression. Modern, efficient engines thus tend towards the pent roof or hemi designs, where the valves are brought close in to the centre of the space. Where fuel quality is low and octane rating is poor, compression ratios will be restricted. In these cases, the sidevalve engine still has much to offer. In the case of the developed IOE engine for a market with poor fuels, engines such as Rolls-Royce B series or the Land-Rover use a complicated arrangement of inclined valves, a cylinder head line at an angle to the bore and corresponding angled pistons to provide a compact combustion chamber approaching the near-hemispherical ideal; such engines remained in production into the 1990s, only being replaced when the fuels available'in the field' became more to be diesel than petrol. Internally, the cylinder head has passages called ports or tracts for the fuel/air mixture to travel to the inlet valves from the intake manifold, for exhaust gases to travel from the exhaust valves to the exhaust manifold.
In a water-cooled engine, the cylinder head contains integral ducts and passages for the engines' coolant—usually a mixture of water and antifreeze—to facilitate the transfer of excess heat away from the head, therefore the engine in general. In the overhead valve design, the cylinder head contains the poppet valves and the spark plugs, along with tracts or'ports' for the inlet and exhaust gases; the operation of the valves is initiated by the engine's camshaft, sited within the cylinder block, its moment of operation is transmitted to the valves' pushrods, rocker arms mounted on a rocker shaft—the rocker arms and shaft being located within the cylinder head. In the overhead camshaft design, the cylinder head contains the valves, spark plugs and inlet/exhaust tracts just like the OHV engine, but the camshaft is now contained within the cylinder head; the camshaft may be seated centrally between each offset row of inlet and exhaust valves, still utilizing rocker arms, or the camshaft may be seated directly above the valves eliminating the rocker arms and utilizing'bucket' tappets.
The number of cylinder heads in an engine is a function of the engine configuration. All inline engines today use a single cylinder head that serves all the cylinders. A V engine has two cylinder heads, one for each cylinder bank of the'V'. For a few compact'narrow angle' V engines, such as the Volkswagen VR6, the angle between the cylinder banks is so narrow that it uses a single head spanning the two banks. A flat engine has two heads. Most radial engines have one head for each cylinder, although this is of the monobloc form wherein the head is made as an integral part of the cylinder; this is common for motorcycles, such head/cylinder components are referred-to as barrels. Some engines medium- and large-capacity diesel engines built for industrial, power generation, heavy traction purposes have individual cylinder heads for each cylinder; this reduces repair costs as a single failed head on a
BMW 5 Series (E34)
The BMW E34 is the third generation of the BMW 5 Series, produced from 1987 until 1996. Launched as a sedan, the E34 saw a "Touring" wagon body style in 1990, a first for the 5 Series. BMW replaced the E34 with the E39 5 Series in December 1995, although E34 Touring models remained in production until June 1996; the E34 generation included the first all-wheel drive 5 Series with the 525iX, the first V8 in a 5 Series. The E34 saw the introduction of stability control, traction control a 6-speed manual transmission and adjustable damping to the 5 Series range. There was an unusually large range of engines fitted over its lifetime as nine different engine families were used; these consisted of straight-six and V8 engines. The E34 M5 is powered by the S38 straight-six engine and was produced in sedan and wagon body styles. Development ran from July 1981 to early 1987, with the initial design proposal penned by Ercole Spada in 1982. Under the guidance of chief designer Claus Luthe, BMW based much of the design on the E32 7 Series.
Following Spada's departure from BMW and styling approval in 1983, J Mays finalized the design for production in mid-1985. In December 1987, the E34 sedan was unveiled to global press. Special attention was paid to aerodynamics, with the E34 having a drag coefficient of 0.30. Official performance figures are as follows. 5-speed Getrag 260 5-speed Getrag 280 — 3.6 L M5 model only 5-speed ZF S5D 310 — M50 engines 6-speed Getrag 420G — 540i and 1994-1996 M5 only 4-speed ZF 4HP22 - M20 and M30 engines 4-speed GM 4L30-E - M50 engines 5-speed ZF 5HP18 - M50 and M51 engines and 1992-1995 530i. 5-speed ZF 5HP30 - 540i Front suspension consists of double pivot MacPherson struts, with a replaceable shock absorber cartridge inside a steel strut housing. Control arms and thrust arms control side-to-side movement. Steering on most models is a recirculating ball design, however the all-wheel drive 525iX uses a rack and pinion steering system. Rear suspension consists of semi-trailing arms with coil springs integrated in a strut assembly.
The base model, available only in Europe with a total of 53,248 units produced, was powered by the four-cylinder M40 engine, replaced by the M43 in 1994. The 518i was available in sedan or wagon body styles, but with only a 5-speed manual for the transmission; the lowest six-cylinder model and the base model in some countries, the 520i was the second most popular E34 model globally, with 426,971 units produced. Initial production of the 520i started in January 1988. In 1990 the M20 was replaced by the twin-cam M50 engine, updated to the M50TU in September 1992 with the introduction of VANOS; the M50-powered 520i was the most popular E34 variant sold in Europe. The tds was introduced in 1991 using. Available in both sedan and wagon body styles A mid-range model in most regions, the six-cylinder 525i was the most popular E34 model globally, with 434,549 units produced. Like the 520i, the 525i was powered by the M20 engine, updated to the M50 and M50TU engines; the 525iX was the first all-wheel drive 5 Series, the only all-wheel drive model in the E34 range.
Powered by the M50 engine and available in both sedan and wagon body styles, it saw a total of only 9,366 units. The centre differential would divide 36% torque to the front axle and 64% to the rear axle, but could adjust the ratio according to driving conditions in case one of the wheels started to slip. Unique to the 525iX was the use of a pinion steering system. There are two versions of the 530i: a six-cylinder model produced from 1988 to 1990, a V8 model produced from 1992 to 1995. In total 57,570 units were produced; the earlier model, powered by the M30, was not sold in North America. The V8 version, which replaced the six-cylinder 535i in the lineup, was powered by the new M60 engine and was available in sedan and wagon body styles. Transmission choices for the V8 version were a 5-speed automatic; the V8 models were differentiated from other models by the wide grill. Powered the six-cylinder M30B35 and only available as a sedan, the 535i saw a total of 97,679 units produced, which includes the Alpina B10 models.
The 535i was replaced by the V8 engined 530i and 540i models in 1993. Despite the 535i designation and'3.5' casting on the intake manifold, the M30 6-cylinder engine found in the E34 535i was 3.4 litres. In 1992, the 540i model was added to the top of the 5 Series lineup, powered by the M60 V8 engine and available in both sedan and wagon body styles. Transmission options were a 5-speed automatic. A total of 26,485 units were produced, with only 3,203 units equipped with a manual transmission; the V8 models were differentiated from other models by the wider grills. In 1994 the wide grills became available on other models as well; the E34 range was launched in October 1988 in North America with the 525i and 535i 6-cylinder models for the 1989 MY. Over the course of the E34 generation, the 525i Touring, 530i, 530i Touring, 540i and M5 models were sold in North America; the 3.6 L version of the M5 remained in production until 1993, by which time the 3.8 L version was being produced for other regions.
Introduced in September 1988 and produced until August 1995, the E34 M5 was produced in both sedan and Touring body styles, a first for the badge. The E34 M5 is po
An engine block is the structure which contains the cylinders, other parts, of an internal combustion engine. In an early automotive engine, the engine block consisted of just the cylinder block, to which a separate crankcase was attached. Modern engine blocks have the crankcase integrated with the cylinder block as a single component. Engine blocks also include elements such as coolant passages and oil galleries; the term "cylinder block" is used interchangeably with engine block, although technically the block of a modern engine would be classified as a monobloc. Another common term for an engine block is "block"; the main structure of an engine consists of the cylinders, coolant passages, oil galleries and cylinder head. The first production engines of the 1880s to 1920s used separate components for each of these elements, which were bolted together during engine assembly. Modern engines, however combine many of these elements into a single component, in order to reduce production costs; the evolution from separate components to an engine block integrating several elements has been a gradual progression throughout the history of internal combustion engines.
The integration of elements has relied on the development of machining techniques. For example, a practical low-cost V8 engine was not feasible until Ford developed the techniques used to build the Ford flathead V8 engine; these techniques were applied to other engines and manufacturers. A cylinder block is the structure which contains the cylinder, plus any cylinder sleeves and coolant passages. In the earliest decades of internal combustion engine development, cylinders were cast individually, so cylinder blocks were produced individually for each cylinder. Following that, engines began to combine two or three cylinders into a single cylinder block, with an engine combining several of these cylinder blocks combined together. In early engines with multiple cylinder banks — such as a V6, V8 or flat-6 engine — each bank was a separate cylinder block. Since the 1930s, mass production methods have developed to allow both banks of cylinders to be integrated into the same cylinder block. Wet liner cylinder blocks use cylinder walls that are 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 a sleeve. Advantages of wet liners are a lower mass, reduced space requirement and that the coolant liquid is heated quicker from a cold start, which reduces start-up fuel consumption and provides heating for the car cabin sooner. Dry liner cylinder blocks 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. For either wet or dry liner designs, the liners can be replaced allowing overhaul or rebuild without replacement of the block itself, although this is not a practical repair option. An engine where all the cylinders share a common block is called a monobloc engine. Most modern engines use a monoblock design of some type, therefore few modern engines have a separate block for each cylinder.
This has led to the term "engine block" implying a monobloc design and the term monobloc itself is used. In the early years of the internal combustion engine, casting technology could produce either large castings, or castings with complex internal cores to allow for water jackets, but not both simultaneously. Most early engines those with more than four cylinders, had their cylinders cast as pairs or triplets of cylinders bolted to a single crankcase; as casting techniques improved, an entire cylinder block of 4, 6, or 8 cylinders could be produced in one piece. This monobloc construction was more cost effective to produce. For engines with an inline configuration, this meant that all the cylinders, plus the crankcase, could be produced in a single component. One of the early engines produced using this method is the 4-cylinder engine in the Ford Model T, introduced in 1908; the method spread to straight-six engines and was used by the mid-1920s. Up until the 1930s, most V engines retained a separate block casting for each cylinder bank, with both bolted onto a common crankcase.
For economy, some engines were designed to use identical castings for each bank and right. A rare exception is the Lancia 22½° narrow-angle V12 of 1919, which used a single block casting combining both banks; the Ford flathead V-8 — introduced in 1932 — represented a significant development in the production of affordable V engines. It was the first V8 engine with a single engine block casting, putting a V8 into an affordable car for the first time; the communal water jacket of monobloc designs permitted closer spacing between cylinders. The monobloc design improved the mechanical stiffness of the engine against bending and the important torsional twist, as cylinder numbers, engine lengths, power ratings increased. Most engines blocks today, except some unusual V or radial engines, are a monobloc for all the cylinders, plus an integrated crankcase. In such cases, the skirts of the cylinder banks form a crankcase area of sorts, still called a crankcase despite no longer being a discrete part. Use of steel cylinder liners and bearing shells minimizes
BMW 3 Series (E30)
The BMW E30 is the second generation of BMW 3 Series, produced from 1982-1994 and replaced the E21 3 Series. The model range included coupe and convertible body styles, as well as being the first 3 Series to be produced in sedan and wagon/estate body styles, it was powered by four-cylinder petrol, six-cylinder petrol and six-cylinder diesel engines, the latter a first for the 3 Series. The E30 325iX model was the first 3 Series; the first BMW M3 model was built on the E30 platform and was powered by the high-revving BMW S14 four-cylinder petrol engine, which produced 175 kW in its final European-only iteration. The BMW Z1 roadster was based on the E30 platform. Following the launch of the E36 3 Series in 1990, the E30 began to be phased out. Development of the E30 3 Series began in July 1976, with styling being developed under chief designer Claus Luthe with exterior styling led by Boyke Boyer. In 1978, the final design was approved, with design freeze being completed in 1979. BMW's launch film for the E30 shows the design process including Computer-aided design, crash testing and wind-tunnel testing.
The car was released at the end of November 1982. Externally, the E30's appearance is similar to twin headlight versions of its E21 predecessor, however there are various detail changes in styling to the E30. Major differences to the E21 include the interior and a revised suspension, the latter to reduce the oversteer for which the E21 was criticised. In addition to the two-door sedan and Baur convertible body styles of its E21 predecessors, the E30 was available as a four-door sedan and five-door station wagon; the Touring body style began life as a prototype built by BMW engineer Max Reisböck in his friend's garage in 1984 and began production in 1987. The factory convertible version began production in 1985, with the Baur convertible conversions remaining available alongside it; the E30 used carryover four-cylinder and six-cylinder petrol engines from its E21 predecessor. Over the production run, new families of four-cylinder petrol engines were introduced and the six-cylinder engine received various upgrades.
A six-cylinder diesel engine was introduced, in both aspirated and turbocharged forms. Factory specifications are shown below. * With catalytic converter: 90 kW, 230 N⋅m ** With catalytic converter: 125 kW, 221 N⋅m At the launch of the E30 range in 1982, the 316 used a 1766 cc version of the M10 fed by a carburetor and producing 66 kW. The 318i had the same M10 engine, but with Bosch L-Jetronic fuel-injection, increasing power to 77 kW while improving fuel economy; the 1987 Series 2 update introduced a new four-cylinder engine: the M40, which used Bosch Motronic fuel-injection. In the 318i, a 1,796 cc version of the M40 was used; the 316i model replaced the 316, using a 1,596 cc version of the M40. The 318iS coupe was released in 1989; this is the most modern engine available in the E30 range, incorporating DOHC, the updated Bosch Motronic 1.3, hydraulic valve adjusters and coil-on-plug ignition. In some markets, the M42 engine was used in the 318i/318iC models, instead of the M40; the M3 is powered by a high-revving four-cylinder engine.
At the launch of the E30 range, the six-cylinder models consisted of the 320i, which had a 2.0 L version of the M20 producing 92 kW, the 323i, with a 2.3 L M20 producing 102 kW, both using Bosch L-Jetronic fuel injection. These models were not sold in North America for emissions reasons. In 1985, the 2.3 L engine was replaced with a 2.5 L version of the M20, which produced 125 kW and used Bosch Motronic fuel injection. This engine was available in the 325i variants, including the all-wheel drive 325iX. An economy version called the 325e was released with more fuel efficient engine; the e is an abbreviation for eta, used to represent the thermal efficiency of a heat engine. To maximise low-rev torque, the 325e engine was the largest available in an E30; the 325e engine had a longer stroke than the 325i version, with a more restrictive head, four cam bearings instead of seven, single valve springs. For versions without a catalytic converter, the 325e engine produced 90 kW at 4250 rpm and 240 N⋅m at 3250 rpm.
By comparison, peak torque for the 325i engine was 215 N⋅m at 4000 rpm. The 1987 Series 2 update boosted the 320i to 95 kW and the 325i to 125 kW, improved fuel economy. In 1983 the 324td was unveiled at the Germany; the M21 engine used a Garrett turbocharger. The engine uses mechanical fuel injection. In 1985 BMW introduced the 324d, a aspirated version of the same M21 engine, popular in countries with a high motor vehicle tax. In 1987 an electronically controlled fuel pump was used; the updated engine has a decreasing turbo lag. In total, eight transmissions were available for the various models of the E30: five manuals, two automatics. 4-speed Getrag 242 -- 316 and 318i models 5-speed Getrag 240 -- 318i and 320i models. 5-speed Getrag 260 — 323i, 325e, 325es and 325i models. 5-speed Getrag 265 — M3 model. 3-speed ZF 3HP22 — 1981 to 1985. 4-speed ZF 4HP22 — 320i and
The BMW M60 is a aspirated V8 petrol engine, produced from 1992 to 1996. It was BMW's first V8 engine in over 25 years; the M60 was replaced by the BMW M62 engine. During the 1970s, BMW produced a prototype V8 engine for the E23 7 Series, however this engine did not reach production. Development of the M60 began in 1984; the M60 engine has double overhead camshafts with four valves per cylinder. The camshaft is driven by a dual-row timing chain with a self-adjusting tensioner. Valves had hydraulic lash adjustment to reduce maintenance; the ignition and fuel injection systems are controlled by the Bosch Motronic 3.3 system, the ignition system is a coil-on-plug design with knock sensors. To reduce weight, the engine uses aluminum for both the engine block and cylinder head, magnesium valve covers and a plastic intake manifold; the M60 was BMW's first car engine to use a "split conrod" design, where sintered connecting rods are made as a single piece and fractured in order to ensure a closer fit. The dry weight of the engine is between 203 kg.
The M60B30 has a stroke of 67.6 mm, for a displacement of 2,997 cc. Compression ratio is 10.5:1, giving an output of 160 kW at 290 N ⋅ m at 4500 rpm. Applications: 1992–1995 E34 530i 1992–1994 E32 730i 1994–1996 E38 730i The M60B40 has a bore of 89 mm and a stroke of 80 mm, for a total displacement of 3,982 cc. Compression ratio is 10.0:1, giving 210 kW at 400 N ⋅ m at 4500 rpm. It had a forged crankshaft. Applications: 1993–1995 E34 540i 1992–1994 E32 740i 1994–1996 E38 740i 1992–1996 E31 840i 1993–1998 De Tomaso Guarà Alpina produced a high compression version of the M60B40 for the BMW Alpina B10 4.0 and the B11 4.0 and in some B8 4.0 models produced for the Japanese market. The M60 engine produced 232 kW in the B10 4.0. The engine's displacement was enlarged to 4,619 cc for use in the B8 4.6 and B10 4.6. The power output is 250 kW in the B10 4.6 and 245 kW in the B8 4.6. The M60 uses Nikasil- an alloy containing aluminium and silicon alloy- to line the cylinders bores. In fuels with high sulfur content, the sulfur damages the Nikasil bore lining, causing the engine to lose compression.
In the U. S. and U. K. sulfur rich fuel is being phased out. BMW replaced engines under warranty and Nikasil was replaced by Alusil. Nikasil engines are unlikely to be a problem today, as cars with affected engines are off the road or have received replacement engines. BMW List of BMW engines
Timing belt (camshaft)
A timing belt, timing chain, or cambelt is a part of an internal combustion engine that synchronizes the rotation of the crankshaft and the camshaft so that the engine's valves open and close at the proper times during each cylinder's intake and exhaust strokes. In an interference engine the timing belt or chain is critical to preventing the piston from striking the valves. A timing belt is a toothed belt—a drive belt with teeth on the inside surface. A timing chain is a roller chain. Many modern production automobile engines use a timing belt to synchronize crankshaft and camshaft rotation; the use of a timing belt or chain instead of gear drive enables engine designers to place the camshaft further from the crankshaft, in engines with multiple camshafts a timing belt or chain enables the camshafts to be placed further from each other. Timing chains were common on production automobiles through the 1970s and 1980s, when timing belts became the norm, but timing chains have seen a resurgence in recent years.
Timing chains are more durable than timing belts—though neither is as durable as gear drive—however, timing belts are lighter, less expensive, operate more quietly. In the internal combustion engine application the timing belt or chain connects the crankshaft to the camshaft, which in turn control the opening and closing of the engine's valves. A four-stroke engine requires that the valves open and close once every other revolution of the crankshaft; the timing belt does this. It has teeth to turn the camshaft synchronised with the crankshaft, is designed for a particular engine. In some engine designs the timing belt may be used to drive other engine components such as the water pump and oil pump. Gear or chain systems are used to connect the crankshaft to the camshaft at the correct timing; however and shafts constrain the relative location of the crankshaft and camshafts. Where the crankshaft and camshaft are close together, as in pushrod engines, most engine designers use a short chain drive rather than a direct gear drive.
This is because gear drives suffer from frequent torque reversal as the cam profiles "kick back" against the drive from the crank, leading to excessive noise and wear. Fibre or nylon covered gears, with more resilience, are used instead of steel gears where direct drive is used. Commercial engines and aircraft engines use steel gears only, as a fibre or nylon coated gear can fail and without warning. A belt or chain allows much more flexibility in the relative locations of the crankshaft and camshafts. While chains and gears may be more durable, rubber composite belts are quieter in their operation, are less expensive and more efficient, by dint of being lighter, when compared with a gear or chain system. Timing belts do not require lubrication, essential with a timing chain or gears. A timing belt is a specific application of a synchronous belt used to transmit rotational power synchronously. Timing belts are covered by metal or polymer timing belt covers which require removal for inspection or replacement.
Engine manufacturers recommend replacement at specific intervals. The manufacturer may recommend the replacement of other parts, such as the water pump, when the timing belt is replaced because the additional cost to replace the water pump is negligible compared to the cost of accessing the timing belt. In an interference engine, or one whose valves extend into the path of the piston, failure of the timing belt invariably results in costly and, in some cases, irreparable engine damage, as some valves will be held open when they should not be and thus will be struck by the pistons. Indicators that the timing chain may need to be replaced include a rattling noise from the front of the engine. Timing belts time periods. Failure to replace the belt can result in complete breakdown or catastrophic engine failure in interference engines; the owner's manual maintenance schedule is the source of timing belt replacement intervals every 30,000 to 50,000 miles. It is common to replace the timing belt tensioner at the same time.
The usual failure modes of timing belts are either stripped teeth or delamination and unraveling of the fiber cores. Breakage of the belt, because of the nature of the high tensile fibers, is uncommon. Overlooked and dirt that mix with oil and grease can wear at the belt and materials advancing the wear process, causing premature belt failure. Correct belt tension is critical - too loose and the belt will whip, too tight and it will whine and put excess strain on the bearings of the cogs. In either case belt life will be drastically shortened. Aside from the belt itself common is a failure of the tensioner, and/or the various gear and idler bearings, causing the belt to derail; when an automotive timing belt is replaced, care must be taken to ensure that the valve and piston movements are synchronized. Failure to synchronize can lead to problems with valve timing, this in turn, in extremes, can cause collision between valves and pistons in interference engines; this is not a problem unique to timing belts since the same issue exists with all other cam/crank timing methods such as gears or chains.
A timing belt is rubber with high-tensile fibres running the length of the belt as tension members. The belt itself