BMW S50B32 Engine
|Also called||BMW S50|
|Cylinder block alloy||Cast-iron|
4 valves per cylinder
|Piston stroke, mm (inch)||91 (3.58)|
|Cylinder bore, mm (inch)||86.4 (3.40)|
|Displacement||3201 cc (195.3 cu in)|
|Power output||228 kW (310HP) at 7,400 rpm
236 kW (321 HP) at 7,400 rpm
|Torque output||340 Nm (251 lb·ft) at 3,250 rpm
350 Nm (258 lb·ft) at 3,250 rpm
|HP per liter||96.8
|Weight, kg (lbs)||154 (340)|
|Fuel consumption, L/100 km (mpg)
|for E36 M3 Euro
|Oil consumption , L/1000 km
(qt. per miles)
|up to 1.0
(1 qt. per 750 miles)
|Recommended engine oil||0W-30
|Engine oil capacity, L (qt.)||5.5 (5.8)|
|Oil change interval, km (miles)||5,000-10,000
|Normal engine operating temperature, °C (F)||~90 (195)|
|Engine lifespan, km (miles)
-No life span loss
|The engine is installed in||BMW M3 E36
In 1995 time came to modify the 6-cylinder S50B30 engine to raise its power on new level and to make BMW M3 E36 faster and dynamic. The new engine named S50B32 and it became the most powerful in the M50 series (it includes M50B20, M50B24, M50B25 and S50B30). The main difference – the increased displacement to 3.2 liter. Engineers installed in the S50 cylinder block the new forged crankshaft (with a piston stroke of 91 mm), and diameter of cylinders increased to 86.4 mm. At the same time used connecting rods with graphite coating (length 139 mm), lightweight pistons (piston compression height – 32.3 mm). The compression ratio increased up 10.8 to 11.3.
In S50B32 improved the cylinder head. For the first time used continuously variable valve timing system on intake and exhaust camshafts – Double-VANOS on BMW engines. Also changed diameter of inlet valves it increased to 35 mm, diameter of exhaust valves remained the same, stem diameter decreased up 7 mm to 6 mm. Dual mass flywheel, exhaust system changed. The intake system became thicker and shorter.
The firing order for the BMW S50B32 engines is 1-5-3-6-2-4. The stock size of fuel injectors – 250 cc/min.
The electronic control unit in S50B32 engine – Siemens MSS50.
All these modifications gave the chance to naturally aspirated BMW to conquer level in 100 horsepower per 1 liter of displacement. This motor showed 321 HP at 7,400 rpm, and a torque 350 Nm at 3,250 rpm.
Produced a modification for Republic of South Africa. It differed in pistons with compression ratio 10.5. Power of M3 E36 was 310 horsepower at 7,400 rpm, and a torque 340 Nm at 3,250 rpm.
S50B32 didn’t install on the cars intended for North America market. Such BMW M3 E36 used S52B32.
This engine only used on the BMW E36 M3 and Z3M.
In 2000 S50B32 was laid off. Next generation of M3 E46 had more modern S54B32.
BMW S50B32 engine problems and malfunctions
The main problems of S50B32 are similar to S50. Learn about them more in details HERE.
S50 NA tuning. Turbo
The best mods for your S50B32 are following: a cold air intake, Schrick 284 camshafts, with valve springs, headers, performance exhaust system (or straight pipe). Then you have to adjust ECU for new performance parts. As a result you get about 360+ horsepower. For even more power, you need to remove VANOS. Then buy 316/308 Schrick camshafts, tappets and springs. You will also need lightweight rods and high compression pistons (CR~13), large valves and port and polish cylinder head, airbox, fuel injectors 500 cc/min. These mods will increase the maximum revs to 9,000 rpm and develop to 400 horsepower.
In addition to the construction naturally aspirated version, using S50B32 you can make BMW M3 turbo (Vi-PEC V88 ECU or other aftermarket ECU), with a power of 500-600 HP or more. Description of the process HERE.