BMW M30 Engine: Description And Characteristics. The Heart Of The ...

The M30 engine is a large inline 6-cylinder engine with 2.5, 2.8, 3.0, 3.2 and 3.5 liter displacement. It can be found on the 5 Series (E12, E28 and E34), 6 Series (E24) and 7 Series (E23 and E32), as well as the famous BMW M1.

The engine turned out to be very successful, both in design and in survivability. Of course, partly the survivability of the engine was provided by its high power. Due to the fact that more powerful motors also load less.

Only the modification of the M30B35 with a cylinder diameter of 93.4 mm was unsuccessful - it turned out to be too energy-loaded. But do not confuse it with the M30B34, which was installed on almost all 3.5 liter cars.

The M30 is an engine for a quiet ride, it has a too heavy piston and too large piston strokes, which do not allow it to spin up quickly and create heavy loads on the bearings (liners).

Also, due to the high mass of the piston system, the engine is very picky about oil, if you feed it with mineral oil and at the same time keep it in the 4-6 thousand rpm range, after a few thousand you will have to grind the crankshaft. Only synthetic oil needs to be poured into this engine, and if you like to turn it, then on volumes of more than 2.8 liters, an oil cooler must be installed.

On the other hand, the advantages of inline-six balance and high power at low revs more than compensate for these disadvantages.

Also, the M30 was the second and last engine to be turbocharged as standard - the turbocharged versions of the M30 were used only in the 745i in the E23 body. In fact, their volume was 3.2 and 3.4 liters, depending on the modification. But both variants were marked M102. The power is the same - 252 hp. The main difference is the ignition and power supply system.

The engine was installed on cars of the third, fifth, sixth and seventh series.

3rd series: E30- 333i - 3.2. liters, with the Motronic injection system. Supplied only to the UAE. 5th series: E12- 525 - 2.5 liters with carburetor, 528 - 2.8 liters. with carburetor and injector, 535i - 3.5 liters, with injector only. E28- models 525i, 528i, and from 1985 535i and M535i. Starting with the E28 body, only injection modifications were installed. E34- 530i - 3 liters., 535i - 3.5 liters. Also, only an injector with a Motronic injection system and a crankshaft position sensor located on the crankshaft damper, and not on the gearbox. 6th series: E24- 628CS with carburetor and injection (628CSi), 633CSi, 635CSi - injector only. 7th series: E23- 728 injector / carburetor, 730 carburetor, 732i / 733i, 735i, 745i - a turbocharged version of the engine was installed on the 745i model. E32- 730i, 735i - 3.0 and 3.5 liters, respectively.

BMW M30 engine block heads.

The cylinder head of the BMW M30 engine is perhaps the most unified of all.

Only the carburetor and injection heads have cardinal differences, and the difference is so strong that it is impossible to interchange them in principle.

Otherwise, the heads of the block are completely identical, up to the valve timing (camshafts).

Otherwise, in the design of the cylinder head there are no cardinal differences from other BMW engines. The movement of gases through the engine is transverse, the combustion chambers have a three-spherical shape, a V-shaped arrangement of valves with an overhead camshaft.

Valve disc diameter:

Inlet Outlet

Height of the cylinder head of the M30 engine: 129 ± 0.1 mm. Reducing the height of the cylinder head during grinding is allowed by an amount not more than: 0.5 mm (in this case, it is necessary to grind the timing gear cover by the same amount). Minimum permissible cylinder head height since model year 1980: 128.6 mm.

Piston system

Distinctive characteristics of pistons. Engine pistons have their own distinctive marks: Marking on the bottom of standard pistons: engine type / compression ratio (for example 2.8 / 9.3); diameter of the piston skirt (for example, 85.97); as well as an arrow for orienting the piston in the cylinder during installation.

Specifications

For all M30s:

Volume

Diameter cylinders

St. Szh.

Power (hp)

Max. moment (H * m)

Detailed technical information about the engine.

Basic technical data
A type: M86, M30	petrol
Number and arrangement of cylinders
Number of valves	2 per cylinder
Fuel system types
Carburetor (E12 only) L-Jetronic (only on E28)
Carburetor L-Jetronic
Carburetor L-Jetronic (USA only) Motronic 1.3 (E32, E34)
L-Jetronic (up to 9/79 and up to 09/80 for Sweden) Motronic 1.0 (from 09/79)
L-Jetronic Motronic 1.0 Motronic 1.0 Adaptive Motronic 1.3 (E32, E34)
Cylinder diameters
Piston group
Unique for each type
Identical for all engine types
Crankshaft: Stroke:
Working volume, cm 3
Interchangeability	Fully interchangeable, but without changing the carburetor-injection
Valve seats	pressed into the cylinder head
Valve guides
Cylinder head height
Maximum allowable cylinder head height reduction during grinding	0.5 (in this case, it is necessary to grind the cover of the distribution mechanism by the same amount)
Gas movement	transverse
Three-spherical CS
Cylinder head gasket
The cylinder head gasket is installed in only one position, dry, with the exception of the front (on the side of the camshaft drive), to which apply sealant.
It is not allowed to install a carburetor engine cylinder head gasket on an engine equipped with a fuel injection system.
Valve seats.
Valve guides
The valve guides are cast iron and pressed into the cylinder head. The sizes of the guide bushings of the intake and exhaust valves are the same.
Length up to 80g with 80g
Outside diameter	14 +0,033 +0,044
Inner diameter
Cylinder head socket diameter
Repair dimensions:
increased by 0.1
increased by 0.2
Preload when pressing the valve guides into the cylinder head: up to 78 from 78	0,033-0,0690,015-0,044.
Protrusion of the valve guides relative to the plane of the cylinder head
Heating temperature of the cylinder head when pressing in the valve guides, 0 С
Valve springs
The valve springs are the same for the intake and exhaust valves. Springs are color coded down and towards the cylinder head.
Spring diameter
M86, M30 up to 06.86
M30 c 06.86 External Internal	31.2 mm 21.2 mm
Valves
The valves are steel, the rods are chrome-plated.
Valve disc diameter
The total open angle of the intake and exhaust valves, degrees:
Lift height of camshaft cams of engines
From the 82nd year:
Gas distribution mechanism (GRM)
Chain tensioner plunger length
Number of teeth:
Crankshaft sprockets
Camshaft sprockets
Number of chain links
Number of chain rows:
Pistons
The maximum allowable clearance in operation between the piston and the cylinder
The difference in the mass of pistons in the assembly of one engine	no more than 10 g
Connecting rods
Weight tolerance:
For one engine
Lower head
Top head

Engine	Disassemble and assemble
Engine only	Remove and install
Engine only (with automatic gearbox installed)	Remove and install
Engine. Replacing the unit	Remove and install
Engine repair. "Short" block "	Remove and install
Compression pressure	Check
Valve cover and gasket	Remove and install
Valves. Clearances	Check and adjust
Valves. Stem compaction	Remove and install
Cylinder head	Disassemble and assemble
Cylinder head and gasket	Remove and install
Camshaft	Remove and install
Camshaft. Drive belt / chain	Remove and install
Crankshaft. Rear oil seal	Remove and install
Crankshaft. Rear oil seal (with power steering system installed)	Remove and install
Crankshaft. Main bearings	Remove and install
Crankshaft. Front oil seal	Remove and install
Piston rings	Remove and install
Connecting rods and pistons	Remove and install
Oil pressure	Check
Oil pan	Remove and install
Oil cooler	Remove and install

Initially, based on the M30 engine, a model was developed with two camshafts and a two-row chain, as well as 4 valves per cylinder. The cylinder head consisted of two parts: the lower one formed the combustion chambers and the "cooling jacket", and the upper one was the gas distribution mechanism. Fuel was injected individually into each cylinder through a special Kugelfischer intake manifold, with 6 distinctive intake pipes on the cylinder head. This version of the engine was installed from 1978 to 1981 on BMW M1 supercars and had a power of 277 hp. Later, during the fuel crisis, the same engine, with minor modifications and M88 / 3 coding, was installed on the BMW M635CSi, and later received the S38 B35 marking. The modification of the M88 engine of the M1 sports car, which was intended for racing in the Procar series, was boosted to 470 - 490 hp. This unit was distinguished by new camshafts, larger valves, forged pistons, and electromagnetic valves were used in the intake system (instead of throttle valves), in addition, a modified exhaust manifold was installed. To participate in Group 5 races, the engine power was increased to 850 - 900 hp. by additional installation of two turbochargers. This power plant received the index - M88 / 2. From 1985 to 1987, the M88 was used in the BMW M5 and from 1983 to 1989 in the BMW 6 Series - the M635CSi. This engine modification had the M88 / 3 index and developed a power of 286 hp.

So, there were the following options:

BMW M88 / 1 engine

The M88 / 1 engine was the first iteration of the M88 and was installed in the BMW M1. Engine displacement 3453 cc. It produced 277 hp. (207 kW) at 6500 rpm and 324 Nm at 5500 rpm. Produced from 1978 to 1981

BMW M88 / 2 engine

Engine displacement 3453 cc. For group 5 races, the M88 engine was turbocharged and became known as the M88 / 2. This racing engine produced up to 900 hp. (670 kW).

BMW M88 / 3 engine

The M88 / 1 engine also known as the S31B35ME was modified for use in the BMW E24 M635 CSi and BMW E28 M5 vehicles, this engine was known as the M88 / 3. Engine displacement 3453 cc. The Kugelfisher fuel injection was replaced with Bosch Motronic and the engine produced 286 hp. (213 kW) at 6500 rpm and the torque was 340 Nm at 4500 rpm. The M88 / 3 engine was also fitted to the South African BMW E23 745i, due to packaging problems with the turbocharged engine in the M102, which has been used in other markets. The BMW M88 / 3 engine was produced from 1983 to 1989.

BMW M90 engine

The smaller M90 engine with a single overhead camshaft (SOHC) 3453 cc, which was based on the BMW M88 engine. It uses the same block from the M88 and maintains the same bore and stroke, but uses Bosch Motronic for fuel injection instead of Bosch L-Jetronic. Produced from 1978 to 1982. Used on BMW E24 635CSi, BMW E12 M535i and BMW E23 735i.

Specifications:Modification: M88 / 1 The volume is 3453 cm cube. Bore, 93.4 mm Piston stroke 84 mm Compression ratio 9.0: 1 Power @ RPM [email protected]Max. Torque @ RPM [email protected]Injection type: Kugelfischer

Engines of the BMW M30 series are a representative of the oldies. This is a large inline-six that the world saw in 1971. From 1971 to 1975, the engine was equipped with carburetors, after which the injection system became an injection system.

Characteristics and features of motors

The M30 engine received a volume of 3.0 liters. Cast iron block paired with an aluminum head, no modern bells and whistles. The gas distribution mechanism has a chain drive.

BMW E21 with M30 engine

The M30B30 carburetor model appeared along with the injection model in 1971, had a compression ratio of 9 and developed 180 hp. at 6000 rpm. The injection model came with Bosch D-Jetronic injection and a compression ratio of 9.5, which made it possible to remove 200 hp. at 5500 rpm.

Since 1976, Solex Zenith 35/40 INAT carburettors have been replaced by Solex DVF-4A1. The power of these motors increased to 184 hp. at 5800 rpm, and since 1979, instead of the carburetor M30B30, they began to install the injection M30B28.

M30 engine

In 1975, the injection M30B30s were modified: the compression ratio was reduced to 9, the injection was replaced by Bosch L-Jetronic and this was reflected in the power, which dropped to 195 hp. at 5800 rpm.

In 1986, the M30B30 engine was installed on a new, at that time, BMW 730i E32. This engine had a compression ratio of 9.2 and developed 197 hp. at 5800 rpm. A version with a catalyst and a compression ratio of 9 was produced, its power was 188 hp. at 5800 rpm.

Consider the main technical characteristics of the M30 series motors:

Service

Maintenance of M30 motors is no different from standard power units of this class. Maintenance of motors is carried out at intervals of 10,000 km. The recommended service must be carried out every 7,500 km. So, let's look at a detailed technical service card:

TO-1: Oil change, oil filter change. Carried out after the first 1000-1500 km of run. This stage is also called the break-in stage, since the engine elements are lapped.

TO-2: The second maintenance is carried out after 10,000 km of run. So, the engine oil and filter, as well as the air filter element are changed again. At this stage, the pressure on the engine is also measured.

TO-3: At this stage, which is performed after 20,000 km, the standard procedure for changing the oil, replacing the fuel filter, as well as diagnostics of all engine systems is carried out.

TO-4: The fourth maintenance is perhaps the simplest. After 30,000 km, only the oil and the oil filter element change.

TO-5: The fifth TO for the engine, like a second wind.

Typical malfunctions

In principle, all motors are similar in design and performance. So, let's consider what common problems can be found on the M30:

BMW M30 engine repair process

1. Oil leak. It occurs as a result of the breakdown of one of the gaskets.
2. Overheat. A common cause of a BMW malfunction. In this case, it is worthwhile to diagnose the cooling system - a thermostat, water pump or radiator.
3. Does not start. The problem may be hiding in the gas pump or candles. It is worth checking the other elements of the fuel system.

Conclusion

The M30 engine is an old man worthy of respect. Maintenance and repair of the power unit can be carried out independently. Many motorists of the late 80s - early 90s remember this power unit and know about its reliability.

Each car company has its own successful designs. Most of them remain at the conceptual level, fate is more favorable to some, and they still end up in the series. But only a few are worthy, as they say, to go through the centuries and remain in the annals of history. The greatest development at BMW, I think, is the M30 series engine. A motor that combined the incompatible: sport, comfort, torque and power. And, most importantly, not every motor can boast of such a long production period.

In 1979, part of the M30 engine lineup underwent changes. This year has become a landmark for the M30, as this year there is a completely new intake manifold of a very unusual configuration. If you remember the early manifold, everything was clear there: pipes of equal length led to each cylinder for the least resistance to the incoming air. But the early manifold has one undeniable drawback: it takes up too much space and impairs access to the oil filter, which is located on the driver's side.

The new manifold is a kind of three-story structure, where the first floor supplies air to cylinders 1 and 6, the second to 2 and 5, and the third to 3 and 4 cylinders. But with such an arrangement, the question is pertinent: how could BMW engineers spit on the racing fate of the engine, which, by the way, was in full swing? The answer is both simple and complex at the same time. Inside the manifold there are small bumps that create certain air turbulences that contribute to the fullest possible filling of the combustion chamber. The whole physics of this process was calculated in an empire way, since not a single most powerful computer even today can cope with this task, therefore, the fact of creating such a product in principle causes me great respect for the BMW minders.

With the advent of a new collector, and the modernization process dragged on from 1979 to September 1982, depending on the volume, all motors of the M30 series began to be equipped with a very unusual, but extremely necessary device. The 7th, the so-called starting nozzle was screwed into the collector from below, near the sockets. Its original purpose is to simplify starting a cold engine by feeding a portion of fuel directly into the cylinders, bypassing 6 standard injectors. But the BMW minders came up with an ingenious idea: to flash their brains for the emergency activation of the injector, either when the gas is pressed sharply, or when 5500 rpm is reached. This gave an additional "charge" that was not required for a quiet ride. This very interesting fact also explains the fact that even the most serviceable restyled M30s "spit" with fire after the cut-off.

But let's go back 2 years ago, to 1977. This year, the Motorsport division got its first thoughts on a twin-shaft engine. This decision was expected, since a significant increase in the power of atmospheric М30В35 was required without reducing the resource. At the first stage, the task was to design exclusively the cylinder head itself without any other changes in principle. Considering that this engine will be actively used in racing, a dry sump lubrication system was introduced. Further, the thermostat underwent modification, which, due to the increased size of the cylinder head, did not rise to its native place. A different thermostat led to more and more changes in attachments, therefore, as a result, only the block remained from the M30V35.

Georg Thill - Chief Engineer Engineer Motorsport GmbH from 1976 to 1985

The intake manifold on the M88 engine is 6-throttle, the solution is simple and trouble-free, and most importantly, not a single horse is lost at the intake, each of which is so valuable in the heat of the fight with rivals. The oil pump, as well as the water pump, were replaced with more efficient ones, so that the engine felt confident at high revs. Actually, for the sake of high revs, it was decided to completely sacrifice the moment, therefore, 282/282 camshafts with a rise of 11.0 were used in the cylinder head as standard. Together with the LE-Jetronic injection, the engine power was 277 forces, and the torque was 338 Nm. The first and only central-engined supercar BMW M1 was equipped with this engine.

In 1983, when Eberhard von Künheim nevertheless decided to release the BMW M635CSi e24, there was little to do: figure out what kind of engine to put in the car, so as not to burn out very much in case of failure, but also not to fall face down in the mud if such a wicked novelty will become popular. Paul Roche, the head of Motorsport GmbH, who replaced Johan Neerpach in 1981, made a proposal to install a modified M88 engine with the M88 / 3 index.

Despite all the insanity of the idea, the M88 / 3 with the latest Bosch Motronic injection at that time and a simple wet sump lubrication system with a capacity of 286 forces and a torque of 351 Nm took its place under the hood of the BMW six, and a year later it appeared in BMW M5 e28. This motor is extremely unusual in operation. Rough idling, accompanied by strong vibration, a high probability of engine overheating in traffic jams, as well as oil starvation, lasting up to 4500 rpm, make the same M5 or M635CSi very difficult for everyday use. But what else can we expect from a racing engine, which, through simple machinations, is already capable of developing 400 forces?

In 2010, I had a chance to ride an M5 E28, and I remember the feelings from that trip as it is now. Up to 3000 rpm, the motor is simply dead. No traction, no sound, just a treacherously low level of oil pressure in the engine, and nothing more. From 3 to 4.5 thousand, the motor seems to begin to come to life, but still it is not perceived as something worth being afraid of. But as soon as the tachometer needle crosses the mark "4500" ... this is where the real show called "The Wolf in Sheep's Clothing" begins! The motor begins to growl menacingly and rush forward, like a fighting dog that sees its enemy! Such a radical change in "mood" is nothing more than the merit of the "evil" camshafts, which are tuned only for maximum revs. In this mode, the car really wakes up and accelerates the one and a half ton sedan to the control hundred in 6.5 seconds! And it is in this mode that the engine, having quenched its oil thirst, sings its aria with pleasure in a baritone.

The M88 / 3 engine has a rich history. In addition to its racing variations with a capacity of from 350 to 850 forces, which crushed everyone and everything in championships from ETCC and Group 2 to the top Group 5, this engine is famous for a huge number of the craziest tuning projects.

This engine was destined to be in the "three-ruble note" e30, and in the "seven" e23, and even in the 124th Mercedes!

In 1988, all world magazines touted the novelty of the German car industry in the face of the BMW M5 e34. The S38B36 engine, which was a further development of the M88 / 3, deserved special praise. This is the same classic inline-six with a 24-valve cylinder head, 6-throttle intake, "evil" shafts and forged pistons, but with one small difference. This time, the motor was rebuilt, with a focus on operation in a quiet city mode.

S38B36

S36B38

That the 315-horsepower S38B36, that its 340-horsepower version of the S38B38, updated in 1991, the engines are quieter and more balanced. They don't have the sudden explosive effect of their racing ancestor. These motors are inherent in a more even shelf of moment, they are not afraid to stand in traffic jams for many hours, they are not shaken, but in no case have they lost their fighting qualities. It is not without reason that the BMW M5 e34 was called the Businessman Express: a comfortable and high-profile car that can turn into a real conqueror of autobahns and race tracks at any time!

Having told about the sports branches of the M30 engine, I cannot fail to mention the experiments of BMW AG in the field of engine turbocharging. This technology of increasing power was successfully used in motorsport, which is clearly shown by the Formula 1 car of Nelson Piquet, which developed 1200 forces from 4 cylinders and two liters of volume! Relying on racing experience, BMW minders in cooperation with Motorsport minders tried in 1978 to create a turbo engine with the M102 index based on M30V32 for a luxury sedan, that is, for a BMW seven in the back of an e23. In 1983, this engine was created on the basis of the already 3.4-liter M30B34 block (restyled M30B35) and was called the M106. Both motors were equipped with a KKK ball bearing turbine K27 without water cooling of the central part.

The differences between the M102 / M106 and M30 motors can be called microscopic, since they are visible only with a very detailed examination, however, these differences make almost all parts of the motors non-interchangeable. So, for example, the block contains oil jets pressed into the upper part of the main bearings. They help cool and lubricate the piston pins and pistons. And to feed these nozzles, vertical oil channels are made in the block, which are also absent on atmospheric blocks. The pistons from the turbo engine have recesses that help reduce the compression ratio, which is necessary for installing the turbine, otherwise the block would simply burst into pieces. Due to the installation of a supercharger, all rings, both oil scraper and compression rings, were replaced with stronger ones.

The M102 / M106 cylinder head also differs from the M30 head. In the turbo version, the exhaust manifold is attached with studs with a diameter of 10 millimeters, while in the "aspirated" the studs have a diameter of 8 millimeters, which is justified by a simple reinforcement of the structure, so as not to "tear off". As strange as it may sound, the camshaft on the M30 and on the M102 / 106 is the same! But if you look at it, then there is nothing surprising here, because the runoff phases and the rise are more than enough even for engines with a turbine! But the valves are different depending on the type of air supply. The exhaust valves of the M102 / 106 are made of sodium alloy for better cooling.

The Westgate M102 / 106 has a stamped top and 1 additional port for boost pressure control. Westgate controls boost pressure by directing excess exhaust gases around the turbine impeller. A spring installed in the wastegate housing presses the valve until the gas pressure is sufficient to overcome the spring force. Blow-offs were installed on the M102, as BMW was planning to use manual transmissions on the 745i. Then this idea was abandoned, and the bypass valve was no longer installed on the M106, although the space for it was still left.

Another 10 long years of happy production after the last update was in store for the M30 motor. Since 1987, it was produced in only two variations - the 188-strong М30В30 and М30В34, inside which 211 selected German ponies were hiding. And only in 1992, with the appearance on the stage of the 8-cylinder M60 engine, the old M30 was solemnly discontinued. Many of those who have assembled these engines for 27 years saw off the BMW 535i e34, equipped with the latest M30 in history, as they usually see off their favorite actors on their last journey, with all due honors. And the car itself solemnly took its place in the BMW Museum.

The M30 has become the most iconic engine in the history of the Bavarian brand with a propeller on the hood. At one time, there was an insane amount of different tuning for various purposes on it, there were jokes and endless jokes about it, like "If an M30 was not installed in a BMW, then this is not a BMW." Moreover, they say that in Germany there is even more than one monument dedicated to the M30, built with the money of fans. I would like to say a huge thank you to Alex von Falkenhausen for giving us an example of real engineering art, which will remain in the annals of history forever.

BMW M30B35 / M30B34 engine

Characteristics of the M30V35 engine

Production	Munich plant
Engine brand	M30
Years of release	1982-1992
Cylinder block material	cast iron
Supply system	injector
A type	inline
Number of cylinders	6
Valves per cylinder	2
Piston stroke, mm	86
Cylinder diameter, mm	92
Compression ratio	8.09.0 10.0(see description)
Engine displacement, cubic cm	3430
Engine power, hp / rpm	185/5400 211/5700 218/5500 (see description)
Torque, Nm / rpm	290/4000 305/4000 310/4000 (see description)
Fuel	92
Environmental standards	-
Engine weight, kg	~145
Fuel consumption in l / 100 km (for E34 535i)- city - track - mixed.	17.38.0 9.8
Oil consumption, gr. / 1000 km	up to 1000
Engine oil	5W-30 5W-40 10W-40 15W-40
How much oil is in the engine, l	5.75
Oil change is carried out, km	7000-10000
Engine operating temperature, deg.	~90
Engine resource, thousand km- according to the plant- on practice	- 400+
Tuning, h.p. - potential - without loss of resource	800+ n.d.
The engine was installed	BMW M535i E28 BMW 535i E34 BMW 635 CSi E24 BMW 735i E32 BMW M535i E12 BMW 735i E23

BMW M30B35 / M30B34 engine reliability, problems and repair

Before the appearance in 1992 of the M60 series, with a V8 configuration, its place was occupied by large-volume inline sixes, called the M30. Despite the fact that the M30 was produced simultaneously with the M20 (also in-line 6-cylinder), the 30th model has more in common with the younger four M10. The first M30s appeared almost 50 years ago, and over time they were constantly refined and modernized. One of the top variants called M30B35 / M30B34 was released in 1982 and was intended for BMW 35i cars.

The BMW M30B35 / M30B34 engine is an inline six in a cast iron cylinder block, the same as the M30B30, but the crankshaft has a piston stroke of 86 mm (versus 80 mm for the M30B30), the bore has been increased from 89 mm to 92 mm. The cylinder block height is the same. The length of the connecting rod is 135 mm, the compression height of the piston is 39.85 mm. The head of the block of cylinders М30B34 / B35 is single-shaft with 12 valves,without hydraulic lifters, so every 10 thousand km it is advisable to adjust the valves. Inlet and outlet clearances (cold engine) - 0.3 mm. M30B35 camshaft specifications: 248 phase, 8mm lift. The intake manifold has been redesigned using 214 cc injectors. Timing chain drive. The fuel supply system is injector. Various versions of this engine were produced: with a catalyst, pistons for a compression ratio of 8 and Bosch Motronic 1.0, developing 185 hp. at 5400 rpm; without a catalyst and with pistons for a compression ratio of 10, their output is 218 hp. at 5500 rpm; as well as a catalyst version with pistons for a compression ratio of 9 and with Bosch Motronic 1.3, the power of such M30B35 reached 211 hp. at 5700 rpm. In 1992, the M30V35 engine was replaced with a more modern V8 - M60B40.

BMW M30B35 engine problems and malfunctions

1. Overheating. This problem is inherent in many in-line 6-cylinder BMW engines and it is not worth starting it - the cylinder head will drive. The cause of the malfunction is a dirty radiator, pump, thermostat, or air locks in the cooling system. 2. Cracks in the cylinder block. Formed around the threads for the cylinder head bolts, due to the failure to remove oil from the threaded wells after disassembling the engine. Symptoms indicating the appearance of cracks in the M30: antifreeze leaving, emulsion in oil. You can try to solve the issue by repairing, but it is safer and more correct to buy a used cylinder block without cracks.

Given the very advanced age of BMW M30 engines, wear of everything that is possible is added to the above: most often problems arise in the gas distribution mechanism, with the subsequent impossibility of adjusting the valve, this is solved by replacing eccentrics, worn valves, guide bushings. Malfunctions associated with the mass air flow sensor are also frequent. At the moment, all BMW M30 engines have rolled out their resource, despite the fact that it can easily exceed 500,000 km. Also, often cars with M30 are operated quite toughly (especially E34), this additionally leaves its mark. The BMW M30B35 itself is a great engine for its time, but age takes its toll. If you want to buy a BMW and there is a choice between the M30 or the M50 (and other engines of this series), you should take the more recent M50.

BMW M30B35 engine tuning

M30B35 Atmo. Stroker

There are a lot of tuning parts for the M30, and if you have money, you can take off a few horses from it, but first, bring your engine to normal condition, if the engine asks for capital, then no shafts will help you. After restoring the M30B35, there are two ways: to make a stroker or an aspirated shaft on the shafts. The first option involves the installation of a crankshaft with a piston stroke of 98 mm, short connecting rods and cylinder bore for forged pistons of 93.4 mm. This will provide 4.0 liters of working volume, bore to 95 mm, you get 4.2 liters, no more. The cost of such whales is higher than the cost of the entire car. The second way: you need to mill the cylinder head to increase the compression ratio to ~ 11, modify the channels and combustion chambers, you also need a sports intake, a Schrick 284/280 camshaft (or other similar) with springs, reinforced rockers, 76 mm straight-through exhaust and brain tuning ... All this will allow you to remove about 240-250 hp, but the piston is old, heavy, spinning reluctantly, and it is better to replace it with light forging, add an S38 throttle. As a result, it is cheaper to buy a BMW S38 with 340 hp chokes. and make a swap.

Turbo M30B35

BMW M30 engines from the factory have a very low compression ratio, so it is not necessary to unclench it for supercharging, which means it is much easier to inflate than an aspirated one. Buy a cheap Chinese turbo kit for BMW M30 on eBay and install it on the stock motor. Or buy separately the Chinese Garrett GT35, with manifold, 3-inch pipes, intercooler, wastegate, blow-off, 630 cc injectors and Megasquirt control unit. Inflate 0.8-1 bar and get under 400 hp. Chinese turbines do not last long, several thousand kilometers and need to be replaced. The original 35th garrett is much better and more effective, but the price is different at times. Something like this can be assembled using a compressor, but with a turbine it will be more efficient.