BMW S54 Engine

1. Specifications
2. Overview, problems
3. Performance tuning

BMW S54 engine specs

BMW S54 engine reliability, problems and repair

In 2000 there was next BMW M3 in E46 body. Neither the motor for North America not for Europe used in this model. Now in E46 M3 install only S54. This motor is the flagship of series M54 (which included M54B22, M54B25 and M54B30).
New S54 inline-6 based on the European version BMW S50B32. Cast-iron cylinder block of this engine has been improved: increased bore to 87 mm, forged crankshaft with a stroke of 91 mm and with 12 counterweights. Also applied reinforced forged connecting rods (length 139 mm), new high compression pistons (CR=11.5), their compression height 32.3 mm. The pistons are cooled by oil spray nozzles.
There were following changes in cylinder head: improved continuously variable valve timing system Double-VANOS, used new cast iron hollow camshafts (duration 260/260, lift 12/12 mm) and decreased weight of the cylinder head. Valves as on S50B32.
S54 still haven’t hydraulic lifters so every 30,000 miles of mileage (50,000 km) you have to adjust valves. Valve clearances are following (cold engine): inlet 0.18 – 0.23 mm, exhaust 0.28 – 0.33 mm. Individual throttle bodies still used on intake. The firing order on BMW S54: 1-5-3-6-2-4. The stock size of fuel injectors of S54 – 247 cc/min.
The electronic control unit of S54B32 – Siemens MSS 54. All these changes helped to increase the power of the engine to 343 horsepower at 7,900 rpm and a torque 365 at 4,900 rpm.
E46 M3 engine with power of 333 HP produced for North American. Differences between US E46 M3 and Euro version consist in two additional catalytic converters. Because of them S54 lost 10 HP.
S54 was a little simplified for BMW Z3M. Its power decreased to 325 HP (Euro version) and to 315 horsepower (US version).
Differences between S54 M3 and S54 Z3M consist in the changed intake manifold and air filter housing. The maximum revs decreased to 7,600 rpm. Two additional catalytic converters cased difference in 10 horsepower between US and Euro versions.
The most powerful modification of S54 installed on the lightweight version E46 M3 CSL. This car produced in 2003 in limited edition. CSL differs from usual S54 by improved intake system, aggressive camshafts (duration 288/280, lift 11.6/11.6 mm), exhaust valves and the lightweight exhaust system. It increase the power of 3.2-liter motor to 360 horsepower at 7,900 rpm. Such engine called S54B32HP.
The S54 installed on M3 E46 till 2006 then there was new M3, with absolutely another V8 motor – S65. Nevertheless, S54 continued to install on Z4M till 2008.

BMW S54 engine problems and malfunctions

Compare with BMW M54, on S54 there are no big problems with engine oil consumption. But if at your M3 is high oil consumption, then a problem in valve stem seals. If the consumption is too large, then you need to buy new piston rings.
Periodically there is an overheat on S54. Main reasons: air in the cooling system, a dirty radiator, a water pump, the thermostat and radiator cap. Check these details.
The lifespan of S54 is quite high, it can go without problems more than 100,000-150,000 miles of mileage (200,000+ km). But as these cars bought for active driving, for today practically all of them are in awful state. After 100,000 miles of mileage (150,000 km) you need to change connecting rod bearings, timing chain and timing chain tensioner on your M3. Generally it is related to engines till 2003, newer motors haven’t such problems.
If you could buy the S54 in a good state, then you shouldn’t save on service, use only high-quality engine oil, observe terms of replacement engine oil and your M3 won’t give you problems.

BMW S54 engine tuning

S54 upgrades

S54 has the highest ratio of horsepower per liter among all naturally aspirated of 6-cylinder BMW engines. Nevertheless, you can get even more power if you spend a little money. For this you need to buy Evolve intake system (or other “CSL Style”), headers, performance exhaust Supersprint (or straight pipe) and AEM Infinity EMS ECU (or Evolve software).
This will allow your S54 easily to show more than 370 horsepower.
The next step is to buy the Schrick 288/280 camshafts lift 12.5 mm with springs. After installation of these cams, to 3,000 rpm the motor will lose power a little, but after 5,000 rpm it will be increase. With such mode your E46 M3 will show about 400 horsepower at 8,500 rpm. Even more power you can get using the Schrick camshafts 304/296 lift 14 mm, but for this VANOS system need to disable. You receive the maximum power if buy high compression pistons (CR=12.5+) and make head porting. It will maximize redline (9,000+ rpm) and develop more than 400 horsepower.
To buy stroker kit for S54 is not a good idea without it you will get good power.
Prices on performance parts for the E46 M3 is high, it may be cheaper to buy a BMW E92 M3.

S54 Supercharger

Instead of difficult manipulations you can just buy an ESS supercharger kit (or VF) and get a lot of power. These sets are quite reliable and install on S54 stock internals. The maximum boost VT1 – 6 psi (0.4 bar) you do not even need forged pistons. It will easily provide 470 horsepower. With the help of a supercharger S54 you can get up to 600 horsepower and that’s enough for any driver.
Make S54 turbo or twin turbo isn’t too favorable, it is quite expensive and easier to buy a faster Nissan GTR.

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