BMW M30 engines
Content
BMW M30 is a popular engine of the German concern, made in various modifications. He received 6 cylinders with 2 valves on each of them, was used on BMW cars from 1968 to 1992. Today, the internal combustion engine is considered obsolete, although different cars still drive it. This unit is deservedly considered one of the most successful engines of the BMW concern due to the unpretentiousness of maintenance, the absence of serious problems and a huge operational resource.
There are 6 main engine versions:
- M30B25
- M30B28
- M30B30
- M30B32
- M30B33
- M30B35
Some versions received additional modifications.
Features
The main parameters of the motor correspond to the table.
| Years of issue | 1968-1992 |
|---|---|
| Cylinder head | Cast iron |
| Food | Injector |
| A type | Inline |
| Number of cylinders | 6 |
| Number of valves | 2 per cylinder, 12 total |
| Piston stroke | 86 mm |
| Bore | 92 mm |
| Compression ratio | 8-10 (depends on exact version) |
| Volume | 2.5-3.5 l (depending on the version) |
| Power | 208 - 310 at 4000 rpm. (depends on version) |
| Torque | 208-305 at 4000 rpm. (depends on version) |
| Fuel consumption | Gasoline AI-92 |
| Fuel consumption | Mixed - about 10 liters per 100 km. |
| Possible oil consumption | Up to 1 l per 1000 km. |
| Required lubricant viscosity | 5W30, 5W40, 10W40, 15W40 |
| Engine oil volume | 5.75 l |
| Working temperature | 90 degrees |
| Resource | Practical - 400+ thousand kilometers |
M30 engines and modifications were installed on BMW 5-7 series 1-2 generations from 1982 to 1992.
Improved versions (for example, M30B28LE, M30B33LE) were installed on BMW cars of 5-7 generations of early production years, and advanced turbocharged internal combustion engines such as M30B33LE can only be found on cars of 6-7 generations.
Modifications
The BMW M30 in-line engine received versions that differ in cylinder size. Naturally, structurally, they differ slightly from each other and, apart from power and torque, they do not have serious differences.
Versions:
- M30B25 is the smallest engine with a displacement of 2.5 liters. It has been produced by the concern since 1968 and was used from 1968 to 1975 on BMW 5 series cars. Power was 145-150 hp. (achieved at 4000 rpm).
- M30B28 - a 2.8-liter engine with a power of 165-170 hp. It can be found on 5 and 7 series sedans.
- M30B30 - ICE with a cylinder capacity of 3 liters and a power of 184-198 hp. at 4000 rpm. The version was installed on BMW 5 and 7 series sedans from 1968 to 1971.
- M30B33 - version with a volume of 3.23 liters, a power of 185-220 hp and a torque of 310 Nm at 4000 rpm. The unit was installed on BMW 635, 735, 535, L6, L7 cars from 1982 to 1988.
- M30B35 - the model with the largest volume in the line - 3.43 liters. Power 211 hp achieved at 4000 rpm, torque - 305 Nm. Installed on models 635, 735, 535 from 1988 to 1993. The version also received various modifications. In particular, the M30B35LE power plant developed power up to 220 hp, and its torque reached 375 Nm at 4000 rpm. Another modification - M30B35MAE - is equipped with a supercharger-turbine and develops power of 252 hp, and its maximum torque is transferred to low revs - 2200 rpm, which provides a quick set of speeds.
Description of motors
M30 motors with different volumes are found on cars of the 5, 6 and 7 series. Regardless of the volume, engines are considered reliable and tenacious. The large resource of internal combustion engines is largely justified precisely by high power, since strong engines are loaded less with moderate city driving, which is why they live longer. The only less successful modification is with a volume of 3.5 liters. It turned out to be energy-loaded and less tenacious compared to other versions.
The most popular in the series is the M30B30 engine - it was installed in the 70-80s on all cars with an index of 30 and 30i. Like its B25 and B28 predecessors, this engine has 6 cylinders in a row. The unit is based on a cast iron block with cylinders with a diameter of 89 mm. There is only one camshaft in the cylinder head (SOHC system), there are also no hydraulic lifters, so after 10 thousand km. valves need to be adjusted.
The timing mechanism uses a chain with a long resource, the power system can be injection or carburetor. The latter was used until 1979, and after that only injectors were used to supply fuel-air mixtures to the cylinders. That is, injection engines are most widely used.
During the entire production period, the M30B30 motors (this also applies to engines with other volumes) have been modified, so there is no standard power and torque for them. For example, the carbureted engine, released in 1971, received a compression ratio of 9, and its power reached 180 hp. In the same year, they also released an injection engine with a compression ratio of 9.5 and a power of 200 hp, achieved at lower speeds - 5500 rpm.
Later, in 1971, other carburetors were used, which changed the technical characteristics of the engine - its power increased to 184 hp. At the same time, the injection units were modified, which affected the power. They received a compression ratio of 9.2, power - 197 hp. at 5800 rpm. It was this unit that was installed on the 730 BMW 32i E1986.
It was the M30B30 that became the "bridgehead" for the production of the M30B33 and M30B35 engines with volumes of 3.2 and 3.5 liters, respectively. In 1994, the M30B30 engines ceased to be produced, replacing them with newer M60B30 units.
BMW M30B33 and M30B35
Engines with volumes of 3.3 and 3.5 liters are bored versions of the M30B30 - they have a larger bore (92 mm) and a piston stroke of 86 mm (30 mm in the B80). The cylinder head also received a single camshaft, 12 valves; There are no hydraulic lifters there, so after 10 thousand kilometers, adjustment of valve clearances was required. By the way, many experts, through simple manipulations, turned the M30B30 into the M30B35. For this, the cylinder block was bored, other pistons and connecting rods were installed. This is the easiest option for tuning this internal combustion engine, allowing you to get an increase of 30-40 hp. If you put in an improved Schrick 284/280 camshaft and make a direct-flow exhaust, install the correct firmware, then the power can be raised to 50-60 hp.
There were several versions of this engine - some had a compression ratio of 8 and were equipped with catalysts, developed power up to 185 hp; others got a compression of 10, but had no catalysts, developed 218 hp. There is also a 9 compression motor with 211 hp, so there is no standard power and torque value.
The tuning possibilities of the M30B35 are extensive - there are tuning components on sale that allow you to unleash the potential of the internal combustion engine. Tuning options are different: you can install a crankshaft with a piston stroke of 98 m, bore the cylinders, increase the volume to 4-4.2 liters, put forged pistons. This will add power, but the cost of work will be high.
You can also buy some Chinese turbo kit with a capacity of 0.8-1 bar - with its help, the power can be raised to 400 hp, though only by 2-3 thousand kilometers, since turbo whales do not live long.
M30 motor problems
Like all motors, M30 engines have some problems, although there are no serious “illnesses” and technical miscalculations inherent in the series. Over the long life of the engines, it was possible to identify the shortcomings:
- Overheat. The problem occurs on many ICEs from BMW with a volume of 3.5 liters. If you notice an increase in temperature, then it is better to immediately check the condition of the cooling system, otherwise the cylinder head will lead very quickly. In 90% of cases, the reason for the increase in temperature lies in the cooling system - the radiator (it can be trivially dirty), pump, thermostat. It is not excluded the banal formation of air jams in the system after replacing the antifreeze.
- Cracks in the cylinder block near the bolt threads. A very serious problem with motors M Typical symptoms: low antifreeze level, formation of an emulsion in the oil. Often cracks form due to the fact that the master did not remove the grease from the threaded wells when assembling the motor. This problem is solved by replacing the cylinder block, it is rarely repaired.
It should also be borne in mind that all M30 engines in the middle of 2018 are old - they have not been produced for a long time, and their resource is almost rolled out. Therefore, they will definitely have problems associated with natural aging. Interruptions in the operation of the gas distribution mechanism, valves (they wear out) and the crankshaft, bushings are not excluded.
Reliability and resource
M30 engines are cool and reliable units with a long resource. Cars based on them can "run" 500 thousand kilometers and even more. At the moment, the roads of Russia are full of cars with ICE data, which are still on the move.
It is also worth highlighting the study of the design and problems of the M30 engines, so replacing or repairing components is easy, but often there are problems finding the right components. Therefore, the repair of the M30 engine may take longer.
Is it worth buying?
Today, these units are sold at specialized sites. For example, a 30 M30B1991 contract engine can be purchased for 45000 rubles. According to the seller, he “ran” only 190000 km, which is not enough for this motor, given that its practical resource reaches 500+ thousand kilometers.
M30B35 can be found for 30000 rubles without attachments.
The final price depends on the condition, mileage, the presence or absence of attachments.
Despite the reliability and technically successful design, all M30 motors are not recommended for purchase today. Their resource is coming to an end, so they are not able to ensure normal uninterrupted operation due to natural old age.
