BMW OHV V8 engine

BMW OHV V8 engine
BMW OHV V8 installed in a BMW 503
Overview
Manufacturer BMW
Production 19541965
Layout
Configuration V8 OHV
Displacement 2,580 cc (157 cu in)
3,168 cc (193 cu in)
Chronology
Predecessor -
Successor BMW M60

The BMW OHV V8 is an overhead valve (pushrod) V8 petrol engine produced from 1954 to 1965. It is BMW's first V8 engine, and BMW did not produce another V8 automobile engine until the M60 in 1992.

The engine does not have an official model code,[1] therefore it is often identified as being the only overhead valve ("OHV") V8 engine produced by BMW, since all other BMW V8 engines use a DOHC valvetrain.

Although not a direct replacement, in 1965 the 6-cylinder M30 took the OHV V8's place at the top of BMW's engine range.

Development

BMW 502
BMW 3.2

The BMW 501, which began production in 1952, was the first car produced by BMW after World War II. It was powered by the 2.0 L (122 cu in) M337 straight-6 engine[2](p46)[3] (based on the pre-war M78 engine), which struggled with the 1,285 kg (2,833 lb) mass of the 501. Mercedes-Benz's competing model, the W187, was powered by a larger 2.2 L (134 cu in) engine, which provided superior performance.[2](p46)

However, BMW had been developing a V8 engine since 1949,[2](p46) which was produced in 2.6 L (159 cu in) and 3.2 L (195 cu in) capacities. The design was finalized by Fritz Fiedler when he returned to BMW in 1952.[4](p90)

In 1954, the V8 engine was introduced (in 2.6 Litre form) in the BMW 502 - a higher specification version of the 501. In 1955, the 3.2 Litre version of the engine was introduced in the BMW 3.2, which was based on the 502.

Design

At the time, unique features of the BMW OHV V8 included the aluminium construction of the block and head, and a coolant passage design that increased the block stiffness over typical engines with wet cylinder liners.[2](p48) The layout of the engine is a longitudinally-mounted 90° V8 with cast iron wet liners and stiffening webs between the cylinders.[2](p48) Apart from the materials, the engine was similar in overall design to the Cadillac OHV V8 and Oldsmobile V8 engine of the late 1940s, with a central camshaft using pushrods to operating overhead valves in crossflow cylinder heads with wedge-shaped combustion chambers.[4](p90)[2](p48)

The 2,580 cc (157 cu in) versions have a bore of 74.0 mm (2.9 in) and a stroke of 75.0 millimetres (2.95 in). Initially, this engine used a two barrel Solex 30 PAAJ carburettor, a compression ratio of 7.0:1[4](p91)[2](p49) and had a power output of 75 kW (100 hp).

The extra capacity of the 3,168 cc (193 cu in) version was achieved by increasing the bore to 82.0 mm (3.2 in). The larger engine initially used a single Zenith 32 mm carburetor, a compression ratio of 7.2:1 and produced 89 kW (120 hp). The highest power output version of the BMW OHV V8 produced 119 kW (160 hp) and was used in the 3200 S released in 1961.[4](p93)

Models

The following is a summary of the engine's variants.[5][6](p508)

EngineDisplacementCarburettorPowerTorqueYears
M502/12,580 cc (157 cu in)Solex 30 PAAJ75 kW (100 bhp)
@ 4800 rpm
184 N⋅m (136 lb⋅ft)
@ 2500 rpm
1954–1961
M502/100Zenith 32 NDIX75 kW (100 bhp)
@ 4800 rpm
185 N⋅m (136 lb⋅ft)
@ 2500 rpm
1961–1963
M502/110,
M533
82 kW (110 bhp)
@ 4900 rpm
186 N⋅m (137 lb⋅ft)
@ 3000 rpm
1961–1963
M506/13,168 cc (193 cu in)Zenith 32 NDIX89 kW (120 bhp)
@ 4900 rpm
214 N⋅m (158 lb⋅ft)
@ 2500 rpm
1955-1961
M506/140,
M534
Zenith 36 NDIX104 kW (140 bhp)
@ 5400 rpm
242 N⋅m (178 lb⋅ft)
@ 3000 rpm
1961-1963
M503/1dual
Zenith 32 NDIX
104 kW (140 bhp)
@ 4800 rpm
220 N⋅m (162 lb⋅ft)
@ 3800 rpm
1956-1961
M507/1112 kW (150 bhp)
@ 5000 rpm
240 N⋅m (177 lb⋅ft)
@ 4000 rpm
1956-1959
M503/160,
M532
dual
Zenith 36 NDIX
119 kW (160 bhp)
@ 5600 rpm
245 N⋅m (181 lb⋅ft)
@ 3600 rpm
1961-1963

M502/1

The original 2.6 L version of the engine was developed for the BMW 502 and was introduced with it in 1954.[2](p48)[4](p92) The compression ratio is 7.0:1. A 95 horsepower (71 kW; 96 PS) version of this engine was available in the 501 V8 of 1955.[4](pp250–251)

In 1958, the 501 V8 and 502 were renamed the 2.6 and 2.6 Luxus respectively, with no changes in engine specification.[4](pp250–251)

Applications:[5]

M502/100 and M502/110

In the summer of 1961, the 2.6 L engines were uprated with the Zenith 32 NDIX carburetor from the earlier 3.2 L engines and a 7.5:1 compression ratio. With this upgrade, the 2.6 became the 100 horsepower (75 kW; 100 PS) 2600 and the 2.6 Luxus became the 110 horsepower (82 kW; 110 PS) 2600 L. These cars continued in production until December 1963[5]

Applications:[5]

M533

M533 is version of M502/110 with gearbox directly mounted to engine.[6](p151)

Applications:

M506/1

The 3.2 L engine was developed in 1956, and was offered in the 502-based 3.2 from then until 1961.[7][4](p93) The compression ratio is 7.2:1.

Applications:

M503/1 and M507/1

BMW's V8 sports models, the 503 and 507, used M503/1 and M507/1 engines respectively, each with a pair of Zenith 32 NDIX two-barrel carburetors. With these, and a compression ratio of 7.5:1, the 503's engine produced 140 horsepower (100 kW) at 5000 rpm. The tuning of the 507's engine went further, with high-lift cams, a different spark advance curve, polished combustion chamber surfaces, and a compression ratio of 7.8:1, producing 150 horsepower (110 kW; 150 PS) at 5000 rpm.[4](p113) Both models were discontinued in March 1959.[4](p115)

The twin-carburetor engine from the 503 was used in the 502-based 3.2 Super from 1957 to 1961.[8]

Applications:[6](p508)

M506/140 and M503/160

The single-carburetor 3.2 and two-carburetor 3.2 Super were replaced in 1961 with the M506/140 (140 horsepower (100 kW)) for 3200 L and the M503/160 (160 horsepower (120 kW)) for 3200 S respectively.[4](p93) The increase in power came from larger Zenith 36 NDIX carburetors and a compression ratio of 9.0:1.[9]

Production of V8 sedans ended in 1963,[4](p93) but the engine from the 3200 S was used in the 3200 CS coupé from January 1962 to September 1965.[4](pp131–132)

Applications:[4](p93)

M532 and M534

M532 and M534 were replacement for M503/160 and M506/140 with gearbox directly mounted to engine.[6](p151)

Applications:[6](p508)[4](pp131–132)

Use by other manufacturers

Frazer-Nash Continental

Frazer-Nash was an importer of BMW cars into the United Kingdom and had used the Bristol straight-six engine, which was based on the BMW M328. The BMW OHV V8 was fitted to the Frazer Nash Continental model.[11] The Continental was intended to be available with either the 2.6 or 3.2-litre V8, but only a single prototype was ever made, with the 3.2 engine. It was the last motor car Frazer-Nash made.[12](p74)

Talbot-Lago America

The 1955 Talbot-Lago Sport was originally powered by Talbot's own 2.5 Litre 4-cylinder engine. In 1957, due to reliability problems, Talbot switched over to the BMW OHV V8 and renamed the car the Talbot-Lago America.[13]

References

  1. "BMW 502 saloon model selection". www.realoem.com. Retrieved 28 May 2017.
  2. 1 2 3 4 5 6 7 8 Noakes, Andrew (2005). The Ultimate History of BMW. Bath, UK: Parragon Publishing. ISBN 1-4054-5316-8.
  3. "1952 BMW 501". www.globalcar.com. Archived from the original on 2 December 2013.
  4. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Norbye, Jan P. (1984). BMW - Bavaria's Driving Machines. Skokie, IL, USA: Publications International. ISBN 0-517-42464-9.
  5. 1 2 3 4 "BMW Classic- Recherche-Client". www.bmw-grouparchiv.de (in German). With searches for individual models. Retrieved 9 June 2017.
  6. 1 2 3 4 5 6 7 Lange, Karlheinz (2000). BMW Dimensions: The History of Engines - Engines That Made History 1945-2000. ISBN 3932169050.
  7. "BMW 501 V8 / 502". www.motorbase.com. Archived from the original on 6 June 2011.
  8. 1 2 "BMW 502 Limousine". www.bmw-classic.com (in German). Archived from the original on 3 December 2013. Retrieved 9 June 2017.
  9. "Betribsanleitung BMW 2600, 2600 L, 3200 L, 3200 S". bmw-grouparchiv.de (in German). Retrieved 7 June 2017.
  10. Norbye 1984, pp. 131-132.
  11. "Snapshot From 1960". www.curbsideclassic.com. Retrieved 9 June 2017.
  12. Gunnell, John (2004). Standard Guide to British Sports Cars. Iola, WI USA: Krause Publications. pp. 73–75. ISBN 0-87349-757-0.
  13. "Lost Marques: Talbot Lago". www.ucapusa.com. Retrieved 9 June 2017.
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