Welcome to ModelEngineMaker !If you have problems registering or logging in, please use the contact menu option to request assistance.
The position of the crankpins needs to be considered, if the cylinders are driving the same crankpin then a 90o V makes sense but if each cylinder drives its own crankpin then you can use any angle of V from 0o to 180o by setting the crank throws to the required offset in order to all the smoothest self starting configuration.