BMW N46B18 engine

The engine is the youngest representative of the N46 family. The B18 was originally based on the B20 model, produced since 2004. The only BMW model that received the N46B18 engine was the E45 316. Already in 2006, the car was removed from production, and the engine failed to become global. The manufacturer intended to launch mass production, alas, the goals failed to materialize. The engine was promptly replaced by its successor, which was characterized by fewer shortcomings and a high rate of output.

Engine specifications N46B18

Advantages

N46B18 differed from its predecessor by camshaft, intake manifold and had minor swap options. Due to the short-stroke crankshaft it was possible to increase power in a narrow torque range. In contrast to the 42 version, the 46 was redesigned almost the entire structure. The control unit of the Valvetronic system was integrated into the ECU. The engine management system was the time-proven Bosch ME 9.2.

Disadvantages

This BMW motor was a veritable treasure trove of factory defects. As is known, owners had to deal with Valvetronic malfunctions and increased oil consumption. The problem was caused by valve seals, which had used up their life. Also the quality of the oil poured in played an important role. After 30 thousand mileage, even with proper maintenance, the owner expected noise in the power unit and vibration in the process of its operation. In this case, the problem was in the tensioner of the timing drive (in 50% of cases the problem was the chain). Already at 50 thousand kilometers of mileage the cylinder-head gasket together with the vacuum pump had to be replaced. Owners of N46 in two-liter version had similar problems.

Modifications

Injector engines are now characterized by wide possibilities for tuning. However, earlier such goals were not pursued. The BMW brand was characterized not only by quality, but also by competent work of marketers.

There were several engine modifications from the factory:

• The N42B18 is the pioneer of its segment and has not been tuned in any way;
• The N46B18 is the direct successor to the N42 and M43 lineup.

N46B18 differed from its predecessor with a modified crankshaft, modified shafts and connecting rods. Similar changes were made to the cylinder-head cover, chain tensioner, and timing mechanism.

The crankshaft on the 1.8-liter engine had a stroke of 81 mm, and the pistons had a compression ratio of 10.2 (the N42B18 has a compression ratio of 10.5).

Chip Tuning

The BMW N46B18 fully adheres to the trends of small German motors. It is not overly adaptable to modifications. among the possibilities for extending the technical potential is to change the firmware.

In addition, the tuning studio offers the installation of a sports filter and removal of the catalytic converter. Such a solution allows you to squeeze an extra ten horsepower out of the engine. The indicator is not cosmic, but it is noticeable in dynamics. If the power of tuning four-cylinder N46B18 is not enough, the only solution is to replace the power unit.

This engine is installed on the following models:

BMW 3-Series (E46)