calculation holes for air passage

[S.O.1212]

Hello everyone!
I wanted to ask a question because I have to consider the drilling of one or more panels for the passage of the air inside a closed group consisting of a motor, alternator and radiator.

as I said the purpose and to make appropriate holes based not only on the radiant surface but also that for the group itself.

do you know how to recommend a site or a specific text that talks about the topic, maybe with some example of calculation?

Thank you in advance!

 

[meccanicamg]

I think they're the secrets of car manufacturers.

If the furi serve to the carburetor to take air I would say that the section of the holes must allow an air flow greater than the one necessary to the combustion otherwise you squeeze and slowly the engine is fatigued.
If it is for a dissipation speech you should have it all drilled.
You should actually do a simulation with a cfd to establish the geometry of the steps.
Surely if you have a radiator you also have a flow of air to dissipate....you have to know.
the two courses are added if they are not able to fish independently and channeled from the outside.