The BMW

BMW

Bayerische Motoren Werke AG is a German automobile, motorcycle and engine manufacturing company founded in 1916. It also owns and produces the Mini marque, and is the parent company of Rolls-Royce Motor Cars. BMW produces motorcycles under BMW Motorrad and Husqvarna brands...

 M88/3 is an in line 6 cylinder (I6)

Straight-6

The straight-six engine or inline-six engine is a six-cylinder internal combustion engine with all six cylinders mounted in a straight line along the crankcase...

 piston engine. It was based on the M88/1 that was used in the BMW M1's street version, with double overhead cam and four valves per cylinder. The M88/1 was in turn based on the M49 engine which was used in the BMW 3.0CSi

BMW E9

-BMW 2.5CS:The last version of the E9 to be introduced was the 2.5CS in 1974. This was a response to the 1973 oil crisis, such that the buyer could choose the smaller, more economical engine. The engine, from the 2500 sedan, displaced and produced at 6000 revolutions per minute...

. The M88/3 was used in the early BMW M635CSi and BMW M5

BMW M5

The first BMW M5, based on the E28 5 Series, made its debut at Amsterdam Motor Show in February 1984. It was the product of demand for an automobile with the carrying capacity of a saloon , but the overall performance of a sports car. It utilized the 535i chassis and an evolution of the engine from...

 (E28

BMW E28

The BMW E28 BMW 5-Series was made between 1981 and 1988. It replaced the BMW E12 in 1981 and was replaced by the BMW E34 in 1989.E28 Production started in July 1981 and ended in December 1987...

) and produced 286 PS (210 kW/282 hp).

BMW engineers used a 4-valve head and a single-row chain. The cylinder head was made in two parts. The lower part formed the combustion chambers and water jackets, and the upper half contained the camshaft bearings and the bores for the tappets.

Kugelfischer fuel injection was used with individual throttle valves and the distinctive six inlet pipes. The M88 produced 277 bhp in the version built from 1978 to 1981 for the BMW M1.

For the Procar M1's, the M88 was tuned to 470 to 490 bhp. The resulting M88/1 engine had new camshafts, bigger valves, reshaped ports, forged pistons, use of throttle slides (instead of butterfly valves), and improved exhaust.

For Group 5 racing, the engine was pushed to between 850 and 900 bhp by the addition of two turbochargers. This was the M88/2 powerplant.

From 1985 to 1987 the M88 was used in the European-market 5 Series M5 (E28) and from 1983 to 1989 in the 6 Series M635CSi Coupe (E24). The engine was designated M88/3 and produced 286 bhp. It was also fitted to the South African 745i as substitute for the turbocharged motor due to the proximity of turbocharger in the right-hand side of engine bay where the steering column and box would be.

S38

The S38 was an updated M88/3 and produced in three versions :

S38 B35 - US-spec BMW M5 (E28) and E24 BMW M6

BMW M6

The BMW M6, also known as the BMW M635CSi, is a high-performance version of the 6-Series automobile, designed by the motorsport division of BMW...

 and late-production catalyst-equipped European market M635CSi (260 DIN HP).

S38 B36 - all US-spec and '89-'92 European-spec BMW M5 (E34)

S38 B38 - '92-'96 European-spec BMW M5 (E34)

The S38 B35 was a revision of M88/3 with dual-row timing chain, reduced compression, catalyst-equipped and fitted with tubular exhaust manifolds rather than equal length "bundle of snakes" headers.

For the S38 B36 displacement was enlarged from 3453 to 3535 cc. Thanks to the use of a Bosch

Robert Bosch GmbH

Robert Bosch GmbH is a multinational engineering and electronics company headquartered in Gerlingen, near Stuttgart, Germany. It is the world's largest supplier of automotive components...

 Motronic 1.2 engine management, power grew to 315 PS (232 kW/310 SAE hp) at 6900 rpm. A dual-stage intake plenum helped to improve flexibility over the rev range. All versions were catalyst-equipped. With respect to the B35 unit, the B36 revision had increased compression and used longer duration camshafts, larger throttles and larger valves. European and US versions both used equal-length exhaust headers.

In 1992, with the introduction of Euro I emission legislation, BMW opted to enlarge the engine once more, to 3795 cc, with power climbing to 340 PS (250 kW/335 SAE hp) and torque

Torque

Torque, moment or moment of force , is the tendency of a force to rotate an object about an axis, fulcrum, or pivot. Just as a force is a push or a pull, a torque can be thought of as a twist....

 going up to 400 Nm (295 ft·lbf). Coil-on-plug ignition replaced the traditional distributor from the B35 & B36. The B38 engine also received a Motronic 3.3 engine management. This engine was used in the M5 until the E34 finished production in 1996.

Production Models

Engine	Displacement	Power	Torque	Bore	Stroke	Year	Application
M88/1	3.5 L (3453 cc)	203 kW @ 6500 rpm	330 newton metre @ 5000 rpm	93.4 mm (3.7 in)	84 mm (3.3 in)	1978–1981	BMW M1 BMW M1 The BMW M1 is a sports car that was produced by German automaker BMW from 1978 to 1981.In the late 1970s, Italian manufacturer Lamborghini entered into an agreement with BMW to build a production racing car in sufficient quantity for homologation. The result was sold to the public, from 1978 to...
M88/3		210 kW @ 6500 rpm	340 newton metre @ 4500 rpm			1983–1989	BMW E28 M5 BMW M5 The first BMW M5, based on the E28 5 Series, made its debut at Amsterdam Motor Show in February 1984. It was the product of demand for an automobile with the carrying capacity of a saloon , but the overall performance of a sports car. It utilized the 535i chassis and an evolution of the engine from... , BMW M635CSi BMW M6 The BMW M6, also known as the BMW M635CSi, is a high-performance version of the 6-Series automobile, designed by the motorsport division of BMW...
S38 B35		188 kW @ 6500 rpm	330 newton metre @ 4500 rpm			1986–1988	BMW E28 M5 BMW M5 The first BMW M5, based on the E28 5 Series, made its debut at Amsterdam Motor Show in February 1984. It was the product of demand for an automobile with the carrying capacity of a saloon , but the overall performance of a sports car. It utilized the 535i chassis and an evolution of the engine from...  (NA spec), BMW M6 BMW M6 The BMW M6, also known as the BMW M635CSi, is a high-performance version of the 6-Series automobile, designed by the motorsport division of BMW...  (NA spec), BMW M635CSi BMW M6 The BMW M6, also known as the BMW M635CSi, is a high-performance version of the 6-Series automobile, designed by the motorsport division of BMW...  with catalytic converter Catalytic converter A catalytic converter is a device used to convert toxic exhaust emissions from an internal combustion engine into non-toxic substances. Inside a catalytic converter, a catalyst stimulates a chemical reaction in which noxious byproducts of combustion are converted to less toxic substances by dint...
S38 B36	3.6 L (3535 cc)	231 kW @ 6900 rpm	360 newton metre @ 4750 rpm	93.4 mm (3.7 in)	86 mm (3.4 in)	1989–1993	BMW E34 M5 BMW M5 The first BMW M5, based on the E28 5 Series, made its debut at Amsterdam Motor Show in February 1984. It was the product of demand for an automobile with the carrying capacity of a saloon , but the overall performance of a sports car. It utilized the 535i chassis and an evolution of the engine from...  (NA spec) and Euro spec 1989-1992
S38 B38	3.8 L (3795 cc)	250 kW @ 6900 rpm	400 newton metre @ 4750 rpm	94.6 mm (3.7 in)	90 mm (3.5 in)	1992–1996	BMW E34 M5 BMW M5 The first BMW M5, based on the E28 5 Series, made its debut at Amsterdam Motor Show in February 1984. It was the product of demand for an automobile with the carrying capacity of a saloon , but the overall performance of a sports car. It utilized the 535i chassis and an evolution of the engine from...