BMW has built a certain reputation for itself over the years as a master builder of inline 6-cylinder engines. They are the brand’s specialty but that doesn’t mean the Bavarians don’t know how to make other engine architectures as well. It took them a while but BMW did come up with a V12, back in the 1980s. Back then, the first BMW V12 would end up as the backbone of a legendary engine otherwise also known as the S70.
In the 1980s things like emissions and gas prices weren’t nearly as restrictive on the way car makers operated as they are today. It was a completely different era from many points of view. Therefore, in the early ’80s, BMW started work on a V12 mill for its 7 Series flagship.
What they came up with was basically a mill created by soldering together two straight six mills, to put it so crudely. The M70, the first-ever BMW V12, was no more than two M20 2.5-liter straight six engines joined at the base.
Of course, there were certain differences between the M70 BMW V12 and the two straight-sixes but the main specs were much the same, such as the compression ratio, the bore and stroke and valvetrain. The joint-together theory gains more traction when you take into account the fact that each cylinder bank had its own ECU.
The video below shows that, even though this approach might seem complicated, it works and the sound it delivers is quite impressive.
The 5-liter mill might not have had the highest power output per liter but it did have a lot of torque from down low, typical for a V12 engine, and useful on a big car such as the 7 Series. The biggest contribution this BMW V12 engine had for the world though, was the fact that it served as a perfect testing bed for the much more powerful and deeply loved S70 mill. Don’t know what that is?
Well, check under the ‘hood’ of a McLaren F1 and you might have a revelation.