Mechanical Engineering - Automobile Engineering - Discussion

Most of the books has given 90. For good balancing of engine.

A v6 engine will generally have an angle of 60° between cylinder banks and a v8 will generally have an angle of 90° between cylinder banks. This relates to primary and secondary imbalances in the engine.

And mostly for balancing even no of cylinders are chosen.

Two full revolutions per cycle=720 degrees of rotation per cycle. 720/8 cylinders = 90 crank pin spacing (not true for a flat plane crank V engine, which is another matter).

720/6 =120 degree crank pin spacing for a V6. I have read that a bank angle of 120 degrees is ideal for a V6 but that few are made that way because of packaging issues, and that 60 degrees, the supplement of 180 is therefore used. I realise there are many exceptions. For example, Ferrari made a 65-degree angle V6, the VW VR6 bank angle is very narrow, and Lancia, I believe, made a 14-degree bank angle V8. But I believe I am correct in saying that 60 is most common for a V6 and 90 for a V8.