BMW M30B33LE engine

The M30B33 engine was released at the end of 1973. It was installed in BMW 3.3 LE cars. The engine was equipped with a Zenith 35/40 INAT carburetor. The M30 series of internal combustion engines were ahead of their time. These were perfect, at the time of release, internal combustion engines. Even now on the roads of Russia, you can meet cars that are actively used, not standing in garages under a tarpaulin. This engine was called the best power unit of the 20th century. In view of the fact that these were modern and at the same time unpretentious internal combustion engines. They gave out enormous torque, a lot of horsepower and incredible potential for tuning. But first things first. And let’s start with the technical specifications.

The exact displacement of the powertrain is 3,295 cubic centimeters and has a compression ratio of 9.0. The working 3.3 liters are capable of producing 190 horsepower at 5,500 rpm. In order to develop a maximum torque of 300 Newton meters, it is necessary to reach 3,500 engine revolutions. The motor weighs 151 kilograms. The protagonist of our review is a bored m30b30. Engineers used in the engine m30b33 larger cylinder diameter and piston stroke than its predecessor. The cylinder head and one camshaft were inherited from the previous model. At the end of 1973, no hydrocompensator was installed on the cars. This led to the fact that every 10-12 thousand kilometers it was necessary to adjust the valve clearances.

There were several versions of the b33. Some power units were equipped with catalytic converters, had a compression ratio of 8 and were capable of producing up to 190 horsepower. Later versions had a compression ratio of 10, but were not equipped with catalytic converters. But, despite this, they developed useful power up to 220 horsepower. The intermediate was an engine with compression of 9 and 211 horsepower. That’s why it is quite difficult to distinguish the average value of power and torque.

M30B33LE engine specifications

Disadvantages

As for problems, the entire M30 line is characterized by almost the same “sore spots”. The first inconvenience is related to overheating, which often leads to a malfunction of the main cylinder block. Imperfection of the cooling system leads to a rapid increase in temperature above the recommended 90 degrees. It is necessary to monitor the pump, thermostat and radiator contamination very carefully.

The next trouble is cracks in the cylinder block that form near the threaded bolts. The main signs of this problem are a permanently low antifreeze level, and emulsion that forms in the oil.

The last, most important reason is that as of the end of 2018, these engines are technically obsolete. And so in addition to the reasons that we mentioned above, very often there will be faults that are related to the natural aging of the parts in the powertrain.

Reliability

As for the reliability of engines of the m30 line, the main indicator is that even at the end of 2018, you can see on the roads of Russia a large number of cars with these engines. Moreover, they are not in the garage, but are actively exploited on the roads. Everyone knows about these engines. Therefore, in order to replace or repair this unit, you do not need to look for specialized service stations. But on the other side of the coin – the market does not have the necessary components.

To summarize, the M30B33 is the standard for German quality and reliability. The engines’ high performance, enormous torque and unpretentiousness will remain in the hearts of motorists for a long time to come.

This engine is installed on the following models:

BMW 7-Series (E23)