Is the Nissan V6 60deg or 90deg? for proper balance V6s should be 60deg ( or 120 but that would not fit into most engine compartments)
I notice that the M-B V6 is 90 degrees... may make for cheaper tooling but one would hope that M-B would make a proper engine.
Are you sure? At least with twin-cylinder engines, the opposite is true. Ducati and Suzuki sport-twins have 90-degree Vs and are known for their perfect balance, whereas the Aprilia 60-degree V-twins require twin counter-balancer shafts.
Here's a detailed in-depth article about engine smoothness:
http://www.autozine.org/technical_school/engine/smooth1.htmFor better balance, most V6s are arranged such that the banks are placed at either 60° or 90° to each other. In this way, the movement of cylinders in bank A matches those in bank B, thus there is no vibration generated between banks.
And it goes on about other engine configs and stuff. Good reading.