Characteristics of the S52 engine
Manufacture and History
The S52 engine was manufactured at the Munich Plant and was used in BMW vehicles from 1995 to 2000. This engine became known for its reliability and excellent performance. The S52 was installed in the BMW M3 E36 and BMW Z3 M models, making them high-performance sports cars.
Design and Materials
The cylinder block of the S52 engine is made of cast iron for high strength and durability. The engine is equipped with an injected power system that provides precise fuel injection and improves performance. The S52 has an in-line configuration with six cylinders, each with four valves. The piston stroke is 89.6 mm and the cylinder diameter is 86.4 mm, which, with a compression ratio of 10.5, provides an engine displacement of 3,152 cubic centimeters.
Performance and Economy
The S52 engine develops 240 horsepower at 6,000 rpm and 320 Nm of torque at 3,800 rpm. The maximum engine speed is 6500 rpm, which allows vehicles to reach high speeds and provide excellent dynamics. It is recommended to use fuel with an octane rating of 95.
S52 complies with Euro 2 environmental standards. The weight of the engine is 141 kg, which makes it light enough to be installed in sports cars.
Fuel and Oil Consumption
Fuel consumption for the E36 M3 with the S52 engine is 16.1 liters per 100 km in the city cycle, 10.1 liters on the highway and 13.3 liters in mixed mode. Oil consumption can reach up to 1000 grams per 1000 km. The S52 engine is suitable for oils with different viscosities, including 0W-30, 0W-40, 5W-30, 5W-40, 10W-40 and 15W-40. The engine oil capacity is 5.5 liters and the recommended oil change interval is 7000-10000 km.
Maintenance and Resource
The operating temperature of the engine is about 90 degrees Celsius. According to the factory data the exact engine resource is not specified, but in practice the S52 engine demonstrates the resource exceeding 400 thousand kilometers, which indicates its high reliability and durability.
Tuning and Potential
The S52 engine has significant tuning potential, allowing you to increase horsepower to 1,000 or more without a significant loss of life, making it an attractive choice for car enthusiasts and professionals looking to improve the performance of their vehicles.
Gearbox and Transmission Ratios
The S52 engine is equipped with two types of transmissions: 5-speed manual (5MKPP) and 5-speed automatic (5AKPP). The manual transmission has the following gear ratios:
- 1st gear – 4.20
- 2nd gear – 2.49
- 3rd gear – 1.66
- 4th gear – 1.24
- 5th gear – 1.00
The automatic transmission has the following gear ratios:
- 1st gear – 3.67
- 2nd gear – 2.00
- 3rd gear – 1.41
- 4th gear – 1.00
- 5th gear – 0.74
The main gear for the 5 mcpd is 3.23, for the 5acpd is 3.38.
BMW’s S52 engine is an example of the combination of high technology and engineering excellence. Its reliability, durability and high tuning potential make it one of the best engines of its time. Installed in BMW M3 E36 and Z3 M models, it provided them with excellent dynamic performance and reliable operation for many years.
Reliability and repair of the BMW S52 B32 engine
After the end of production of the predecessor S50B30, the S50B32 version came to the European market, but it was not supplied for the North American market, the BMW M3 E36 was sold there with its own engine – S52B32. This motor still has nothing to do with the powerful and high revving European M-cars. The American S52 is the flagship of the M52 series (which, in addition to the protagonist, included the M52B20, M52B25 and M52B28) and is a slightly modified B28.
When developing the BMW S52 inline six-cylinder engine, the standard American M52 was taken as a basis; unlike its European counterpart, its cylinder block is cast iron, and for the M-version, the cylinder diameter was increased to 86.4 mm. Inside the block was installed its forged crankshaft S52, with a piston stroke of 89.6 mm, connecting rods long 135 mm, and compression height of the piston is equal to 31 mm. This allowed to increase the displacement to 3.15 liters.
The cylinder head was used from M52 with the following changes: lightweight pushrods, springs, new lightweight camshafts (phase 252/244, lift 10.2/10.2 mm) were used. A different cylinder-head gasket was installed. Intake is ordinary, single-throttle, from M52, exhaust system is a little more perfect.
All this allowed to get 240 hp at 6000 rpm and 320 Nm of torque at 3800 rpm.
The control system of the S52B32 is Siemens MS41.1.
This powertrain was used in BMW M3 E36 and Z3M cars produced for the USA and Canada.
In 2000, the S52 motor was replaced by a real M-engine – the well-known BMW S54.
Problems and disadvantages of BMW S52 engines
The S52 cylinder block is made of aluminum alloy with NICOSIL coating of the working surface of the cylinder walls. This coating, compared to cast iron, is less resistant to various harmful fuel elements, primarily sulfur. The piston rings have a lower height than in the M50 engine. Accordingly, a common problem is the wear of the piston ring, its loss of geometry and elasticity (formation of a gap in the lock up to a frightening 5-8 mm). As a result, oil consumption of 1 liter per 1000 km is reached, on average, already by the mileage of 200 – 230 thousand kilometers. Due to the appearance of a large breakthrough of the working body through the gap in the ring locks in the crankcase cavity, there is a local overheating of the piston, which usually leads to its burnout. Piston burnout can also lead to damage to the cylinder wall (formation of scoring, “piling” of the piston material on the cylinder wall). That is, to the burnout of exhaust valves at high oil consumption, as in the M50, there is also a high probability of piston burnout. It should be noted that both valve burnout and piston burnout occur when the engine is working under a heavy load for a long time, for example, when moving at a speed of more than 160 km/h for more than 20 minutes. That is, if the engine “eats” oil, and you want to delay the repair procedure, the maximum speed should be reduced. This will also reduce oil consumption. Blocks with nicosil coating have no repair dimensions, and the technology of restoration of nicosil coating is not widespread in Russia. If repair is necessary, the block is lined with thin-walled dry liners, piston rings are replaced with those designed to work on cast iron (different types of rings work on nicosil and on cast iron).
In addition to cylinder wall wear problems, aluminum alloy blocks have problems with the threaded holes for the block head mounting bolts. When re-installing the head on the block, there is a high probability that the head mounting bolts will destroy the threads in the block during tightening. The likelihood of this increases to almost 100% if the engine has been overheated. In order to install the head on the block was still possible, in the holes of the block for the head mounting bolts cut a thread of larger diameter, where threaded bushings (futorks) are screwed in, and already in them screwed head bolts. For cars operating on λ-regulation, a large breakthrough of crankcase gases leads to a discrepancy in the values of additive corrections for 1-3 and 4-6 cylinders and, as a consequence, there is an increased unevenness of the internal combustion engine in the idling mode. (Good criteria for assessing the condition of the internal combustion engine).
Appearance of crankcase ventilation system with differential valve (often it is called KRKG) on S52 also added problems. If the valve fails (diaphragm ruptures) or the drain tube of its separator loses patency, oil consumption increases significantly. There are problems with lambda regulation due to the appearance of air infiltration into the intake manifold. Sometimes there are cases of valve freezing with the subsequent increase in pressure in the crankcase cavity and extrusion of any seal (most often – the valve cover gasket). This situation is also typical for M54 engines, but is especially common in E53 body with M62TU engine.
Starting with the M52 engine, the thermostat housing is made of thin plastic, which over time is severely warped and from under it begins to leak antifreeze, which gets to the crankshaft position sensor (DPKV) and leads to its failure. Also on these motors, more often than on M50, there are cases of hydrostroke with deformation (precipitation), less often breakage, connecting rod. The cause of hydrostroke can be water ingress into the intake system through the brake vacuum booster (due to clogged drainage on E39) or when driving through a deep puddle.
Unpleasantly manifested wear of the dual-mass flywheel: the appearance of eccentricity (imbalance) of the dual-mass flywheel leads to the appearance of vibration with the first harmonic in the area of 1200-1400 rpm.
Complaints about “blinking” of the oil pressure lamp are quite frequent. The symptom usually occurs at oil pressure of about 0.6 -0.7 bar when idling (at idle). Despite the fact that the sensor is written 0,2-0,5 bar, at this pressure, the end switch opens only at room temperature, and at 100 degrees the sensor triggers at a pressure of 0,6-0,7 bar. “Little blood” – normalization of the temperature regime, on which the oil pressure strongly depends, and changing the oil to a more viscous, to solve the problem is not always possible, but you can operate the car at this oil pressure. The reasons for the pressure drop are different: wear of the oil pump, “sliding” of the pressure reducing valve, damage of the drain seal in the oil filter cup, wear of the liners, wear of the RV-RV pastel pair, leakage on the VANOS control valve, “sliding” of the valve in the piston cooling nozzle (for engines with the volume of more than 2L).
Tuning engine BMW S52 B32
S52 Atmo. Spreaders
The S52 engine is choked with an intake manifold (the cross-section of the runners is 30% smaller than in the M50), oriented to the lows and medium revs. Therefore, to make your car go faster, you need to buy an M50 intake manifold, cold intake, 252 cc injectors, or a Turner Motorsport Stage 2 kit. This will increase the horsepower to 270hp. Adding Schrick 264/256 camshafts will increase power to 280hp. By installing a sport exhaust system your S52 will show around 290 hp and come close to a European throttle-body S50B30.
This is the easiest and moderately affordable way to upgrade a strangled BMW S52. Nobody forbids to refine the bottom, buy more wicked camshafts, do porting, try to install throttles, however, all this is not easy and not too budget.
S52 Turbo. Compressor
Getting 350 hp on the S52 is realistic, you just need to buy a compressor kit. Most of such offers inflate 0.4 bar and allow you to get an additional 110 hp. The stock motor holds a supercharger up to 400hp and briefly up to 450-500hp (as luck would have it). You just need to buy such a kit and put it on a standard motor and drive until you get bored.
Sooner or later 350 hp will not be enough and you will want not just to drive, but to go full throttle. It is worth to remove the compressor and buy H-beam connecting rods, pistons for compression ratio 8.5 – 9, steel cylinder-head gasket and ARP studs. This will decompress the motor and get it ready for supercharging. Next you need to order a Precision 6266 turbocharger, intercooler, westgate, block-off, pump (such as Walbro 400), fuel pressure regulator. You also need to fabricate a manifold to fit the turbo and a 90mm exhaust system. Once tuned on the Megasquirt (or other ECU), you will get over 600hp.
ENGINE RATING: 5-