When a company for complete cars already calls itself 'Motorenwerke', it's certainly worth to take a look at their range of engines, especially as it is in 2009 right in the transition. We have tried to take over the data as closely as possible.
First there are the measurements for bore and stroke, which are the same for all engines except the V-8. Whether the 0.1 mm difference in the bore are actually present and/or tactical origin, a technical reason for it does not occurs to me now.
This means that even the six cylinders are operated in principle with the same pistons. Of course, differ pistons of the diesel and gasoline engines. One recognizes the enormous degree of rationalization. More nearly can be done, unless you save the six-cylinder in principle.
And that's shown by the development of the 3 series of 2011. Why the larger cylinder numbers disappear you see at the CO2 emissions of the eight-cylinder, the is significantly higher despite latest technology (direct injection) than that of the other engines.
For this purpose a look at the M5, whose picture 2009 actually does not belong here because it is just presented 2011. He also is downgraded from V-10 to V-8. Who has ever heard its soundscape not so much at full throttle, but simply when shortly accelerating, will regret it.
There is still much more in the data. Why will survive the only six-cylinder in the 3 Series just as a turbo engine? Because the six-cylinder aspirated engine with the four-cylinder turbos can barely compete from peak performance, but even more from torque. Then the customer would ask why he has now bought the bigger engine.
Good thing, that it is still in this table as aspirated engine. Look at the compression ratios. The petrol turbos have come up to 1 to 2 points on the naturally aspirated engine. The precise control of boost pressure makes it possible, due to many parameters.
And the diesel engines? What happened to the formerly 18 to 24: 1 in the course of charging? And at other firms, it goes down furtherand the boost pressure is further increased, conditions as with the truck engine are on the horizon.
And significant differences to the charging in the petrol engine. Because there means a strong reduction of the geometric compression ratio, an increase of turbo lag, if that is not compensated by measures at the charging, e.g. retardation as little as possible.
The effort of BMW is noticeable, to give the turbo engines even as little as possible respite when accelerate. Recently, one builds in certain models, instead of two, also already three turbochargers, the cover very effectively different operational areas. 02/12