BMW S50B32 engine

Characteristics

Average fuel consumption for the E36 M3 is 16.9 liters per 100 km in the city, 7.5 liters per 100 km on the highway and 11.0 liters per 100 km in the mixed cycle.

Oil consumption can reach up to 1000 grams per 1000 km. Recommended engine oils include viscosities 0W-30, 0W-40, 5W-30, 5W-40, 10W-40 and 15W-40. The volume of oil in the engine is 5.5 liters. It is recommended to change the oil every 7000-10000 km.

The operating temperature of the engine is approximately 90 degrees Celsius.

The resource of the S50 engine on the factory data is not specified, but in practice it can be estimated at more than 400 thousand kilometers. Tuning potential of this engine can reach 1000 horsepower without loss of resource.

The S50 engine was installed on BMW M3 E36 and BMW Z3 M cars.

Reliability, problems and repair of the engine BMW S50 B32

Progress doesn’t stand still, and in 1995 it was time to improve the good 6-cylinder S50B30 engine to take its power to a new level and make the BMW M3 E36 even faster and more dynamic. The new engine was named S50B32 and was the most powerful in the M50 series (which also included the M50B20, M50B24, M50B25 and S50B30).

Looking at the name of the new power unit, it is not difficult to guess about its working volume. To achieve 3.2 liters in the cylinder block of the S50B30, a forged crankshaft with a stroke of 91 mm was installed, and the cylinder bore was increased to 86.4 mm. Graphite-coated connecting rods with a 139mm length and lightweight pistons with a compression height of 32.3mm were also used, resulting in an increase in compression ratio from 10.8 to 11.3 units.

The cylinder head of the S50B32 was further developed: for the first time, BMW engines utilized the Double-VANOS system of continuously variable valve timing on the intake and exhaust shafts. The characteristics of the camshafts remained unchanged (phase 260/260 degrees, lift 11.3/11.3 mm). The valves were changed: the diameter of the intake valves was increased to 35 mm, and the exhaust valves remained the same, the thickness of the valve stem was reduced from 7 mm to 6 mm. Changes were also made to the dual mass flywheel, exhaust system, and the intake became thicker and shorter.

The control system of the S50B32 is a Siemens MSS50.

All these innovations allowed the production BMW City to break the bar of 100 hp from 1 liter of displacement in the atmospheric version. Thus, the 3.2-liter motor showed an output of 321 hp at 7,400 rpm and torque reached 350 Nm at 3,250 rpm.

There was also a modification for South Africa, characterized by pistons under compression ratio of 10.5. Power of such M3 was 310 hp at 7400 rpm, and torque – 340 Nm at 3250 rpm.

The S50B32 engine was not fitted to cars intended for the North American market; the BMW M3 E36 used the S52B32 instead.

This powertrain was used in the BMW M3 E36 and Z3M. In 2000, the S50B32 was discontinued and its successor, the S54B32, was used in the next generation M3 E46.

Pros and cons of BMW S50B32 engines

Benefits

The S50B32 is considered the most powerful motor of the M50 series, as the engine produces 321 hp at 7400 rpm, with a torque of 350 Nm.

Such impressive results were achieved due to the presence of forged crankshaft, increased to 13.9 cm connecting rods with graphite coating. Manufacturers have installed lighter pistons, the compression ratio was 11.3.

The cylinder head was finalized. For the first time, the manufacturer used a system of constant change of the gas distribution phases on the shafts (intake, exhaust). The valves were modified:

• inlet valve diameter increased to 3.5 cm;
• the diameter of the exhaust valves remained the same;
• the thickness of the stem was reduced to 6 mm

Corrected dual-mass flywheel, exhaust system, intake manifold equal-length became a little shorter.

Siemens MSS50 control system is installed.

Disadvantages

Engine S50B32 has the following most common malfunctions: increased oil consumption, leaks, overheating, failures in the operation of the Vanos system, floating revolutions.

The power unit may overheat. Noticing this problem, you should definitely check the thermostat, radiator. Another common cause is air plugs formed in the cooling system, damage to the radiator cap.

It happens that the engine troits. In this case, you need to check the ignition coils and plugs. If the revs are unstable, the reason may be in the failed idle valve to restore the engine operation is enough to clean them.

Characteristic “rumbling” can be associated with a breakdown of the Vanos system. There is also a loss of engine power, unstable revolutions. To solve this problem, you can not do without a vanos remkompacket. With increased oil consumption, it is worth checking the gaskets of the valve cover, sump, expansion tank.

Periodically in the S50B32 (as well as all “representatives” S50) fail sensors crankshaft, camshaft.

Tuning of the engine BMW S50B32

Camshafts. Turbo

Tuning an S50B32 is similar to tuning an S50B30: you need to buy a cold intake, Schrick 284 camshafts, with springs, a full sport exhaust and do chip tuning. You’ll end up with about 360+ hp. We will get more power by removing the VANOS, by buying the proper kit, then buying Schrick 316/308 camshafts with pushrods and springs. We will need lightweight connecting rods and pistons under compression ratio 13+ units, enlarged valves, as well as porting of the cylinder head, airbox, injectors 500 cc. These mods will allow you to crank the engine past 9000 rpm and develop under 400hp.

MOTOR RATING: 5