BMW M30B32LAE engine

Today on our review BMW 7 series M102 engine with the index M30B32LAE. The power unit is represented by a 6-cylinder motor, which has a working volume of 3.2 liters.  Until April 1983, the unit was fueled by l-jetronic electronics. Under this index was also produced a power unit with a volume of 3.4 liters, with a powertrain power supply system motronic 1.0. The latter version was equipped with a turbine, and the first modification was released in May 1983.

When it comes to the 102 and 103 series, this powertrain lineup is 80% modified M-30 powertrain. Yes, with serious innovations and innovations that were in keeping with its time and customer desires. In this powertrain, the motorists’ emphasis was on maximum power, ease and comfort in the maintenance and operation of the unit.

That’s why the power and ease of maintenance of the engine of those times was much more convenient than modern ones. Power of engines, after two thousand years artificially clamped by ecological norms. But the protagonist of our article was not conceived as the most environmentally friendly and economical engine of its time. But it is necessarily worth pointing out that it was an easy-to-maintain power unit.

The first version came out in 1983. It was one of the most technologically advanced engines from Bavaria Motors at the time. The powertrain won several prestigious awards, and the motorists were proud of their brainchild and installed it on the fifth and seventh series of Bavaria Motors cars. Let’s talk about the features and advantages of this power unit.

M30B32LAE engine specifications

Advantages

Let’s consider the main features of the M102 engine (in comparison with M30): Under the index M30B32LAE two versions of the engine were produced, which had a volume of 3.2 L and 3.4 L respectively. Due to the different displacement, the piston stroke and cylinder diameter increased. In our case, for the power unit with a volume of 3.2 liters characteristic 89 and 86 mm, and for the version with a volume of 3.4 -92 and 86 mm.

As for the pistons of the M102 engine, Bavaria Motors used most of the technology from the North American version of the M30 engine. This version of the engine was famous for its low compression ratio, compared to the other versions. At the same time, connecting rods, piston pins are absolutely identical to those installed on the M30.

Another major difference is that on the M30 version of the engine, the temperature detonation sensor locations were marked, but motorists or service station attendants had to drill the holes themselves. While on the M102 version, the place was prepared for the installation of these sensors. As for the intake manifold, it is fixed with stainless studs, which have a diameter of 10 mm. The exact same fixing can be seen on the M30 engine version.

The M30B302LAE power unit has a combustion chamber with a working volume of 60 cubic centimeters. While the M30 is equipped with a smaller combustion chamber and correspondingly smaller volume of 60 cubic centimeters. As for the innovations that distinguish the M30 from the M102 are the intake valves, which have been coated with sodium filler. This coating significantly improves cooling of the entire system. The throttle position sensor of the M102 is different from that of the M30.

As far as performance is concerned, the 102 series engine significantly beats its smaller sibling in performance because it is equipped with a K27 turbine that has an air cooling system. The entire system is able to maintain its operating temperature thanks to a spigot that attaches to the body. As a result, the turbocharger is cooled by the oncoming airflow. At the same time, on the move, the system is cooled by an electric fan that is integrated into the radiator. Another peculiarity of the unit with the index m102, this is the exhaust manifold, which was the pride of the motorists at Bavaria Motors. The main feature was that it is made of cast iron and, instead of making a single piece, the motorists decided to create it from two parts, which are connected by a stainless steel coupling.

This is a distinctive feature of the protagonist of our review. Another feature is the pressure reducing valve, which from the factory is equipped with additional software that is responsible for supercharger control. This is worth emphasizing, as the motorists have developed a rather unique system.  The pressure that is supercharged in the lower chamber of the reduction manifold is supplied by a solenoid air valve. The corresponding signal is given by the detonation tracking unit. This significantly increases the performance and useful life of the turbine.

Now let’s look specifically at the powertrain power systems. On the engine, which has a working volume of 3.2 liters, installed a power system l-Jetronic and bypass valve. But later, when the engine with a volume of 2.4 liters went into wide production, with a modified Motronic power system, the motorists of the company Bavaria Motors abandoned the bypass valve. L-jetronic also requires special attention. It is for engines that have a small volume, it is a kind of unique system that is responsible for multipoint and intermittent fuel injection. The distinctive feature of this system is that it is economical and significantly reduces the percentage of Co2 emissions in the exhaust gases.

Another interesting feature of the M102 series engines should be noted. Each power unit is equipped with an altitude sensor. Thanks to this detail, the engine is able to develop the power declared by the manufacturer at absolutely any altitude above sea level. It is rather a tribute to fashion and degree of professionalism of Bavaria Motors motorists than a real need for this sensor. But in any case, it shows the attention of Bavaria Motors engineers, but brings an incredible amount of troubles to motorists.

Disadvantages

The first and most common is a crack that occurs in the manifold. It appears due to the constant high operating temperatures of the engine. Another trouble on a technical level is damage to the mechanical pressure reducing valve. As a result, it is prone to premature opening. The solution is quite simple, and is to install a stiff spring on the pressure reducing valve. This artisanal solution was developed by domestic craftsmen at car service stations, and solves the problem with little blood. But you will have to get used to the deterioration of the valve that controls the supercharger.

Despite all the stereotypes, the manual transmission that was paired with the M30 E32 LAE engine, despite the fact that most BMW 745i were equipped with an automatic, has a vulnerable part. It is the torque converter.

Despite all the claims, the Motronic power system has proven itself to be on the best side, but it is seriously cluttered from a technical point of view and is not without vulnerabilities. The first problem is the frequent failures that occur in the ignition circuit. The most common cause is insufficient fit and fixation of the wires.

Another telltale sign that the power system is malfunctioning is jumping rpm at idle. The first thing to look at is the throttle linkage. Over time, the fasteners become unusable. Also wears out the contact track, which is responsible for the air flow meter. This malfunction can lead to late ignition and detonation, due to over-enrichment of the ignition mixture. It is necessary to pay attention to this malfunction, because the flow meter determines the fuel consumption and the correct ratio of the air mixture to the fuel.

Below, we will briefly digest the minor faults that are frequently encountered in the M102/M103 engine range. The power unit may smoke, the most common reasons that cause this problem are high oil level in the crankcase or leakage at the intake and exhaust valves.

Incorrect fuel/air ratio, for which the Motronic system is responsible. Lack of tightness of the fuel injectors.

The BMW m102 power unit was installed in the following BMW E23 745i 1980 – 1982 BMW 745i (E23 body).

Characteristics

It is a gasoline power unit, with a displacement of 3.2 liters and an average output of 252 horsepower. The power unit is turbocharged and is installed on the BMW Seventh Series. The volume of the engine is 3210 cubic centimeters. The maximum power that this unit can develop is equal to 252 horsepower. The torque available under the accelerator pedal is 380 Newtons per meter, once it reaches 4,000 rpm. The powertrain uses gasoline with an octane rating of 95. Average fuel consumption in the mixed cycle is 13.7 – 15.6 liters per 100 km.

By structure, it is an inline 6 cylinder engine. The cylinder diameter is 89 mm. The number of valves per cylinder is 2. Maximum power is 185 kW at 5200 rpm. A turbine is used. The power plant has a compression ratio of 7 and a piston stroke of 86 millimeters.

Chip tuning

As far as chip tuning is concerned, our review protagonist is easy on the computer. In doing so, the vehicle’s performance figures, such as torque and horsepower, are boosted by either custom or factory firmware.

Therefore, it is safe to say that the arrival of the new 7-15 horses does not require any mechanical modifications to the powertrain components. With the new firmware, it is possible to increase engine performance by 5-7 percent without loss of resource. We’re talking about Stage 1. In the case of Stage 2, a more aggressive version of the firmware will affect the overall durability of the powertrain and reduce engine life by 20 to 23 percent.

Of course, engine life will be affected by driving style and general care of the powertrain, but if you squeeze the maximum out of the engine, drive the revs to the red zone, you can significantly reduce the overall life.

As far as mechanical interventions are concerned, this powerplant easily lends itself to boring the cylinder block, replacing the connecting rods and installing a new crankshaft. All this will add about 25 horsepower.

If that’s not enough, the vastness of the internet will allow you to buy a new cylinder head that has more wear-resistant exhaust valves. As for the supercharger modification, these engines have a fairly low compression ratio. The problem is solved by installing a new Garrett GT35 Turbo whale and a control unit on top of that.

All of this will inflate the engine to just over 1 bar of pressure. Failure of a Chinese turbine can cause serious trouble with the powertrain. And don’t forget about installing new brakes and suspension.

This engine is installed on the following models:

BMW 7-Series (E23)