Flow numbers and max HP potential

Cuda416 said

I saw a video choosing a cam that claimed (in a general sense) if you take the flow of an intake port for a given lift, and multiply it by 0.26, that will give you the max theoretical hp for that cyl at that lift. So for magnum heads, that's 233 from the factory as far as I understand, so at that rate, each cyl should be able to support 60.5 HP, or a total of 484 HP. How far off of reality us that? I understand reality over theoretical but software can effectively predict HP based on such things so how far off is this?

Opinions?

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What don’t you by calculators. There are few things to bench race about when it comes to cylinder heads making power. But to break it down to simple, the KISS method would be, cfm X 2 = possible power output and only for a hot street engine. It is reasonable accurate for the basic bench race discussion of what a hot street car or mild track car can pull off.

It is not unreasonable to say a honest 300 cfm head can make 600hp and do it without going overboard on a few things that make for race type only material and fuel. You can build a 600 hp pump gas engine. I just wouldn’t try it with a small engine, like a 340 and expect it to be a grandma smooth idle smooth running delight to drive.