One day I was sitting around wondering "how do you go about selecting the right carburetor size for a given engine?". That ultimately lead to a spreadsheet calculator into which you plug in engine displacement, assumed volumetric efficiency and a series of RPM values, and voila - out come CFM numbers.
The next step came from wondering whether I could get rated engine power outputs to align with theoretical power outputs given typical values for engine efficiency, fuel air ratio, thermal energy contained in gasoline, etc.
These screenshots show how it came out. Not bad at predicting horsepower.
Maybe I could work for Edelbrock.
Note the CFM for a 440 at 5,000 rpm is 637. Then note the predicted horsepower for that flow would be about 375 HP. It's a miracle. Actually, I adjusted the amount of gasoline per cubic foot of charge and the engine efficiency to get it close, BUT, the numbers I used are in fact realistic.
Too Much Time On My Hands
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71_bronze_gtx
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Too Much Time On My Hands
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- Formulas used to calculate flow CFM, and Horsepower
- engine calc. formulas.jpg (11.37 KiB) Viewed 6718 times
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- CFM
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CtownRunner
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moparite
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Re: Too Much Time On My Hands
I guess we can call you the madd scientist of cfm! 
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steved
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Re: Too Much Time On My Hands
would you mind sharing the spreadsheet??
as a mechanical engineer, that sounds really really cool.
sjd
as a mechanical engineer, that sounds really really cool.
sjd
1971 GTX, GY9 Tawny Gold.