ULTIMATE DRIVING MACHINE(S).

Bayerische Motoren Werke – it’s in the name: BMW has developed and built countless engines and power units since the company’s founding. Always perfectly optimized for their area of use, many have left a lasting impression in the history of engine construction. This is especially true of engines made by BMW M, destined for one purpose from the day the company was set up in 1972: motor sport. The know-how transfer from the constant stress test of motor racing to series production of M vehicles was of course intended, but no one imagined the heights that BMW M and its legendary engines would reach.

The abbreviation M30 stood for the big six-cylinder engines from 2.5 litres cubic capacity upwards, which were introduced in the early 1970s in various power levels. To be exact: from an initially hesitant 150 hp right up to a mighty 800 hp in a small number of Group 5 racing cars a few years later. The probably best-known BMW M with a M30 power unit is however the BMW 3.0 CSL. The first product in which the newly founded BMW Motorsport GmbH was involved was based on lightweight versions of the E9 model, which in three production runs provided motors with between 180 and 206 hp. At first with carburettors, later with fuel injection, the combination of car and engine was so successful that the CSL garnered six European Touring Car Championships up to 1979, and outclassed the competition worldwide.

Is there really an engine block with a performance spectrum from 75 to 1,400 hp? Yes, there is. It belongs to a BMW inline four-cylinder unit with the  unspectacular name M10. It was used in many models, from family-friendly estates to the most powerful Formula 1 car ever made. It also propelled the compact BMW 2002 turbo sportscar which was thus the first series model with a turbo engine, supplying 170 hp at a max. torque of 240 Nm. At the beginning of the 1970s, this was most definitely a message to the much more expensive competition, which from this point onwards would always have the 2002 turbo in their rear-view mirrors – easily recognizable thanks to the optional mirror-inverted lettering on the front apron.

“Herr Rosche, we need a sporty engine for the 3 series”, was the request from the then BMW boss Eberhard von Kuenheim to the well-known constructor at BMW Motorsport. Paul Rosche set to work immediately and for the cylinder head chose the one from the M88 engine in the BMW M1. The result was the legendary S14B23: “We were lucky in that the big six-cylinder original had the same cylinder spacing as the four-cylinder. So we went and cut two combustion chambers off the four-valve cylinder head of the M88 and screwed a plate over the hole at the back of the rear front side.”
Why not a six-cylinder as basis? Besides the higher rev stability of the 2.3-litre engine, a low weight for the first BMW M3 was very important: it was then developed as the homologation model for motor sport.

There were several variants of the S14 over the production period, which were used in the evolution models and produced up to 238 hp in the BMW M3 Sport Evolution.

It’s hard to sum up the extremely strong S70/2 12-cylinder: 12 single throttle valves, continuously adjustable inlet timing, two injection jets per cylinder, aluminium flywheel, titanium exhaust rear silencer, dry sump lubrication with four suction pumps and one pressure pump. So much for the most important points. The only common elements with the lower-powered M70 from the BMW 8 series is the cylinder spacing, but every part was constructed anew. This was recognized by the decision-makers at McLaren. They put the 6.1-litre, 627 hp high-performer in the exclusive super sportscar McLaren F1 and later in the F1 GTR racing car. At BMW M itself, the engine was only used in the BMW M8 E31 Prototype. In total, only about 100 of the S70/2 were built.

In 1996, BMW brought out a new V8 engine with the abbreviation M62, which then made its way into the models of the 5 and 7 series. The maximum 347 hp was impressive enough, but the large-volume eight-cylinder only reached its full potential under the aegis of BMW M: named S62B50, it supplied 400 hp to the rear wheels of the BMW M5 E39 and was a major factor in the continuing popularity of the third generation of the high-performance sedan. As US magazine Automobile Magazine wrote in its annual All-Star Competition: “BMW makes the best sports sedans in the world, so it’s little wonder that the company’s ultimate sports sedan, the M5, has won the title again, despite competition that is more impressive than ever.“ Side note: the large-volume V8 also propelled the legendary BMW Z8, which was even good enough for James Bond 007.

Winning the 24 Hours of Le Mans is the ultimate goal of every car-maker. In 1995, it was BMW’s turn, but victory was not so satisfying: the victorious McLaren F1 GTR did have the 12-cylinder BMW M engine under its bonnet, but the chassis came from the British manufacturer. As the engine was still seen as fit for Le Mans, it was further developed as S70/3 for use in the BMW V12 LMR (Le Mans Roadster). The watchword of this power unit was resilience: the six-litre V12 was designed to last a race twice as long as the 24 Hours. In 1999, BMW and the 635 hp V12 LMR then won Le Mans.

After the 1980s, BMW returned to Formula 1 with the E41/2 V10 engine. This engine had – ideally for a V10 engine – a cylinder bank angle of 72°. The power unit from BMW Motorsport was first used in the Williams FW22 on March 12th 2000, with Ralf Schumacher coming in third. Since 1967, no manufacturer in Formula 1 had achieved a more successful debut. In the course of the season, the engineers reworked the engine several times, in the last version the newly-named BMW E41/4 developed around 810 hp at 17,500 rpm. And the sound? Pure adrenaline.

For the S54 engine in the BMW M3 E46, the engineers took the high-rev power unit from its predecessor M3 E36, which had proved so popular with drivers. In its last stage of development, the E36 was already very powerful, but a further reworking in almost every detail increased the output from 321 to 343 hp. Later, in the BMW M3 CSL, the developers managed to squeeze up to 360 hp out of the naturally aspirated engine. That corresponds to a power density of 111 hp –  the hitherto highest figure for a six-cylinder series engine without turbocharger.

The BMW M3 GTR was a sports car used by BMW M in 2001 in the ALMS (American Le Mans Series). Partly responsible for the resounding success of the car which is still legendary today was a very special motor: the P60. The especially light, 450 hp V8 power unit with a displacement of 4.0 litres wasn’t based on a series engine. Here, BMW M still went for the six-cylinder S54. No problem in racing, but the regulations were strict: to satisfy the ALMS rules of the time, 10 units of the BMW M3 GTR “Street” had to be verified to pass as homologation. No sooner said than done: The 250,000 Euro vehicles supply about 350 hp thanks to reduction and adaptations in the exhaust system.

In the mid-2000s, combustion engines with eight, ten or twelve cylinders in series vehicles had reached their zenith. BMW M also switched from a V8 to a newly developed V10 for the new BMW M5 E60. Studded with motorsport details, the extremely lightweight V10 power unit developed 507 hp from a capacity of 5.0 litres – not only the first performance peak over 500 hp, but it could also go up to almost 7,800 rpm. And the sound reminded many M Fans of Formula 1, which also featured V10 engines in 2005.

The first V8 engine in a BMW M3 appeared in 2007. The architecture and aluminium construction were shared by the S65 with the S85 10-cylinder BMW M5 E60 launched in 2005, minus two combustion chambers. The S65 is extremely rev-happy and with maximum revs of 8,400 rpm the highest-revving series engine ever developed by BMW M. Five years in a row, it won top spot at the International Engine of the Year Awards for engines of between three and four litres displacement. The BMW M3 E90 is also the first and last M3 with a V8 power unit.

The return of BMW M Motorsport to prototype endurance racing was set. But the window for developing a suitable engine for the BMW M Hybrid V8 was tight. In 2021, Ulrich Schulz, Head of Engine Construction at BMW M Motorsport, and his team started evaluating which engine would be best for use in the LMDh car. They decided on the ex-DTM P66/1 V8 power unit from 2017, which had been successful in the BMW M4 DTM. The 4.0-litre high-rev engine was not only put under pressure by an exhaust turbocharger, but according to the LMDh regulations also enhanced with a hybrid system. A challenge for the M engineers. But the evolution of the engine paid off: the two BMW M Hybrid V8 vehicles successfully completed their first race, with the first victory coming in the fifth season at the 6 Hours of Watkins Glen in 2023.

The S58 engine is the current development stage of the high-performance inline six-cylinder engine for series vehilces from BMW M. It’s deployed in the BMW M2, M3 and M4, as well as the X3 M and X4 M, and supplies between 480 hp in the basic models and 550 hp, for example in the BMW M4 CS.

Nerd facts: It shares just 10% of components with the B58 Performance engine, so popular in the tuning scene. In the S58 for instance, two single chargers are used instead of a twin-scroll turbocharger, the housing has a particularly pressure-resistant closed-deck construction and the series six-cylinder engine has a short-stroke design in order to improve the rev range. The engine is designed so elaborately because it is used in the BMW M4 GT3 racing car as a P58 with modifications to the turbocharging and oil supply.

The S58’s durability and performance has been proved in the Red Bull Driftbrothers Joe and Elias Hountondji’s BMW M4 Drift Racer. The specially tuned engine develops no less than 1,000 hp – with crank drive, pistons and housing as standard.