BMW S55: the magic of 6 cylinders

BMW s55 is a revolutionary engine with a large fan base. Given its short reigning period, it served well until the much better S58 was replaced. Its longevity, reliability, and high-performance nature make it a dynamic choice for street and track.

Table of Contents

What is BMW?

BMW badge close-up

Bayerische Motoren Werke AG, abbreviated as BMW, stands for Bavarian Motor Works. It is a German multinational automaker of sporty and luxury vehicles and motorcycles. BMW’s headquarters is in Munich, Bavaria, Germany.

The company was founded in 1916. At the start, the domain of this company was to manufacture aircraft engines, which was only done from 1917 to 1918 and continued again from 1933 to 1945; after that, manufacturing aircraft engines for BMW wasn’t an enthusiastic aim as they suffered a little lag in cash flow and investments. After an authoritarian tenure of aimlessness, BMW struck a comeback and started producing some of the finest and most well-renowned automobiles and motorcycles, a mark of excellence to date.

BMW headquarters Munich

BMW has also indulged in motorsport, especially in touring cars, sports cars, and the Isle of Man TT. Manufactured automobiles are marketed under the brands BMW, Mini, and Rolls-Royce, whereas motorcycles are marketed under the brand BMW Motorrad. BMW went on to be one of the most accomplished and decorated manufacturers as, S55’senhancein 2017world’ss the world’s fourteenth-largest motor vehicle producer, with 2,279,503 vehicles produced all around, while BMW was the 7th largest company by revenue.

Headquartered in Munich, BMW also has production plants in many other countries, such as

  • Brazil
  • China
  • India
  • Mexico
  • Netherlands
  • South Africa
  • The United Kingdom
  • United States.

The Quandt family is a long-term shareholder of the company as the Quandt brothers, Herbert and Harald, invested heavily in BMW in 1959, saving BMW from bankruptcy. The public owns other remaining shares.

About the BMW s55

BMW S55 engine

While producing some of the most likable automobiles, BMW is also renowned for manufacturing excellent engines. One of the examples of these great is the BMW s55.

Produced from 2BMW’so date, BMW’s S55 engine is not your average fancy engine. It is a 3.0L twin-turbocharged, direct-injection gasoline engine with a legendary and reliable inline-6 configuration. In a modern world of V-configuration engines, BMW dared to revive the long-lost in-line configuration. Who thought this venture might be a hiBMW’s one of BMW’s most praised products?

BMW S55 engine look

The S55, marking the reintroduction of the inline-6-cylinder dBMW’s to the BMW’s M division M3 after the V8-powered E9X S65, was indeed the best replacement that could ever exist. After the success of the s55 engine in the M3, BMW started offering it in other M models, which was satisfying for the enthdoesn’t. Who doesn’t love a naturally aspirated engine in an M model? But with little tweaks to the s55, more power output was also ensured. The twin-turbo arrangement in the BMW s55 was inspired by the N54 engine, which was very popular due to this twin-turbo arrangement.

BMW S55 engine under the hood

Being a sensation under the hood of a BMW M vehicle, the 3.0 twin-turbocharged S55 engine is heavily based on the BMW N55 engine- a not-so-memorable engine in the M lineup. The S55 engine is an aluminum 3.0L inline-6 engine equipped with a couple of technologies just as in the N55 engine, which is:

  • A double-VANOS
  • Valvetronic variable valve timing.

The Difference between the N55 and BMW S55

N55 vs. S55: A Comparative Overview



Because of the manual valve timing back in the day, the drivers would experience limitations to low-end torque or high-end power. So, the goal was to achieve electronic or automatic timing adjustment to enhance torque on the low end with no compromise in force at the high end, also called Variable Valve Timing. In oBMW’sBMW’swords, BMW’s technology, which allows for Variable Valve Timing, is known as VANOS. All automakers have different names for this technology, such as Honda calling it VTEC.

VANOS technology in BMW

The tBMW’slogies BMW’s s55 uses weren’t double-VANOS or dual-VANOS and Valvetronic variable valve timing. A double VANOS system reins the valves on the intake and exhaust camshafts. The Vanos Solenoids control the camshafts. The benefits of owning the exhaust camshaft are fewer emissions and a quicker engine warm-up time. The dual-Vanos system is also used in the ill-reputed N54 engine and is very much disposed to failure in these engines, but fortunately, the repair is a lot easier. Valvetronic adjusts the height of the valve or the valve lift. Valvetronic also compensates for the need for a throttle body, and Valvetronic combined with VANOS provides:

  • optimal performance
  • Good drivability
  • increased horsepower
  • improved fuel economy and better emissions

Making of the s55

BMW S55 production

As told earlier, the s55 is an Aluminum block, 3.0L inline-6 direct-injection gasoline engine with a twin-mono scrolled turbocharged as aspiration.

BMW S55 aluminum block

Bore x Stroke of 84.0 mm x 89.6 mm with a Compression Ratio of 11.5:1 enables it to produce from 405 to 493 hp. Unlike the N55, it has a closed-deck crankcase design, which decreases the cooling efficiency, so the cooling had to be divided into two circuits for optimal outcomes. Still, the closed-deck crankcase design gave stiffness and more significant cylinder pressure.

BMW S55 in factory being checked

The cylinder bores possess a twin-wire arc-sprayed coating. A twin-wire arc-sprayed layer is a more sophisticated but nimbler atomized metal spray. Friction-reducing Grafal-coated aluminum alloy makes up the pistons.


BMW M2 F87

Offering satisfying numbers of reliability and performance, the s55 engine BMW’ssed in BMW’s major M-models, such as the F87 M2, F80 M3, and F82 M4.


All these models had outrageous statistics, thanks to the revolutionary s55.

Tweaks on the BMW s55

BMW S55 engine cover carbon fiber

The BMW s55 offers a wide range of modifications and tuning, perhaps more than any BMW engine.

Piggyback ECU tune for BMW S55

A piggyback tune that boosts the parameters of the engine and alters specific signals and sensors to accomplish other tuning goals is a popular one that increases the total output up to 80 hp.

Flash ECU tune for BMW S55

Another tune is the Flash tune. It rewrites or engine’sthe engine’s factory DME programming, allowing the tuner to control engine tuning parameters like boost, fueling, timing, and load.

Carbon Fiber charge pipes upgrade

Some other mods include High-flow Downpipes, upgraded Chargepipes, intercoolers, heat exchangers, turbo upgrades, and fueling.

BMW s55’s competition

2JZ engine in a Toyota Supra

The most renowned engine we have heard about and seen is the Toyota 2JZ-GTE. Same as the BMW s55, it also has the inline-6 configuration. The most cherished thing about the 2JZ is its smooth power delivery, longevity, reliable handling of enormous horsepower levels, and numerous modifications and tuning options, as we have seen some 2JZ engines tuned over 1000 hp. However, this engine produces 276-325 hp and 434 Nm of torque- less than the s55 but has a sequential twin-turbocharged aspiration and bore x stroke of 86 mm each. The engine material is the same aluminum block as the s55.


BMW M2 drifitng

BMW s55 is a revolutionary engine with a large fan base. Given its short reigning period, it served well until the much better S58 was replaced. Its longevity, reliability, and high-performance nature make it a dynamic choice for street and track. It has been an element of surprise for the aftermarket enthusiasts as the number of tweaks manageable on it is so exciting. The factor of its in-line configuration has proven to be its main highlight. Overall, the s55 is worth owning and keeping under the hood of your whip.

Issues to keep in mind regarding the BMW s55:

Charge Pipe Issues

Some BMW S55 owners have faced problems with the plastic charge pipes in their engines. Due to the constant heat cycling and high temperatures, these plastic pipes can warp or crack over time. Another related issue involves the rubber couplers connecting the charge pipes to the valve-cover-mounted heat exchanger. If these couplers come loose, it can cause extreme power loss and put the engine into limp mode. A s55’sstandard solution to this problem is upgrading to aftermarket aluminum charge pipes, which are more durable and resistant to heat-related issues.

Valve Cover and Oil Filter Housing Gasket Leaks

Like many engines, the BMW S55 is susceptible to oil leaks from the valve cover gasket and oil filter housing gasket as it ages. The high operating temperatures and continuous heat cycling of the S55 engine can cause these gaskets to degrade over time. Additionally, the S55’s plastic valve cover is prone to warping and cracking. Similarly, the oil filter housing gasket, shared with the N55 engine, can also degrade due to heat cycling and age. Regular replacement of these components is recommended to prevent leaks and maintain the engine’s performance.

Written by: TAZ

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