There is no direct relationship, its entirely upto what the manufacturer is aiming for.
Most cars now are classed in engine size, which affects target market and insurance ratings/tax/registration, so the have capacities groups to play into.
No point having a 2ltr v8 in a production car as the costs will be high as will complexity, but ultimately it has the capability of producing more power due to more total valve area available.
And the bore/stroke relationship (square, over or under square design) affects (along with torque relationship from rod/stroke ratios) if its going to be a high revving high bhp bike engine, low revving high torque tractor engine etc.
Renault wouldnt of considred it because there is no 3ltr 4 cylinder available, and the v6 was a marketing excercise which they used all parts that are already available. If you look under a V6 you can actually see where they cut the bottom/back out and drove a laguna V6 into the space.
large capacity individual cylinders make the physical dimentions of the engine large aswell, and installing a tall engine affects the handling and centre of gravity and overall vehicle styline etc etc etc.
