BMW M10 (M64) engine

The M10 (M64) engine is a gasoline power unit from the famous Bavarian company, which was produced specifically for installation on the first generation BMW third series cars in the E21 body. With a working volume of 2 liters, it is capable of developing up to 125 horsepower of maximum power.

M10 (M64) engine specifications

Advantages

The BMW M64 engine was developed by experienced engineers who were tasked with ensuring maximum practicality and simplicity of design, which was fully achieved. The developers simply placed all cylinders according to the classics – in-line arrangement of all 4 “pots”. The motor is very easy and inexpensive to repair, at the same time, for such work can be undertaken by employees of almost any maintenance service. Engines are considered quite reliable and successful, so finding the necessary spare parts is not very difficult.

The cylinder head is made of high-strength aluminum alloy, while the cylinder block is made of the classic cast iron material. Thanks to this combination of materials, it has been possible to make a motor with minimal weight, which is combined with engine reliability. The driving qualities of the power unit were developed specifically to ensure maximum owner satisfaction, and the engineers succeeded. At the same time, thanks to the use of a cast iron cylinder block, the engine is very easy to overhaul.

The engineers decided that, relative to its axis, the motor is tilted 30 degrees to the right side. This is done to ensure that the negative impact from the forces that occur during motor operation is minimized. Thanks to this solution, it has been possible to maintain the same technical characteristics in combination with a good operating life. Just to ensure that the need for engine overhaul is delayed as much as possible, it is necessary to use quality lubricants and gasoline.

The developers also paid great attention to the location of the exhaust and intake manifolds. These components are located on opposite sides of the engine. Thanks to this arrangement, all engine parts are as accessible as possible, which significantly reduces the cost of repairs and maintenance work.

Disadvantages

One problem faced by owners of such motors is the occurrence of cracks in the cylinder block. Threaded holes, on which the block head with cooling jacket channels is installed, are most often the places of formation of such defects. As a rule, such problems appear as a result of incorrect bolt tightening torque, as well as due to overheating of the motor. Because a crack occurs, coolant can get into the lubricant, causing increased wear on the parts that are rubbing. This is a typical problem that occurs in almost all owners of cars with such motors under the hood, so it is almost impossible to find a cylinder block in normal condition today.

The cam-rocker pair located in the timing mechanism is also characterized by a short service life. If the broken part is not replaced in time, its increased wear leads to difficulties during valve adjustment. If the thermal clearances of the timing valves are adjusted incorrectly, then during the operation of the engine there are unpleasant sounds in the form of scratching, and also it negatively affects the resource of other units in the timing mechanism.

Flaps occurring during the air stroke can cause the air flow meter to break down. The most common cause of such pops is that the air flow meter blade changes its shape, which causes the accelerator pedal to jam constantly when the driver presses it. This is why you need to be careful when setting the ignition timing to avoid big problems.

The power system in the engine corresponds to its age, so the carburetors installed in it often cause problems for owners. But malfunctions do not occur by themselves, but are caused by broken seals or improper adjustment.

Although designers have made every effort to minimize the length of the cylinder head, overheating is not a good thing. The cylinder head can simply warp, or the gasket can be punctured. This is one of the main causes of cracks in the block.

These power units have proven to be as reliable as possible, and are considered one of the best engines that were produced by Bavarian engineers. The M64 gives its owners problems not because of design features, but because of exhaustion or high age.

Technical specifications

The M64 engine (for the US market M74) is a slight modification of the previous model of the M15 engine from Bavarian engineers, which did not receive quite serious innovations.

Maximum power of 125 horsepower is developed at 5.7 thousand rpm. If the motor is cranked up to 4,350 rpm, a peak torque of 175 Nm can be taken off. Production of the engine continued from 1975 to 1979, and it was installed under the hoods of the BMW E21 320i and E12 520i.