I am replying to my own post as a retraction to my assertion of a so called "factor" or a "constant" to simplify venturi area conversions.
Evidently, Don Repp spent some time and checked out my post and politely approached me yesterday at the flying field and explained to me
that there cannot be a fixed factor to convert and that my restrictor diameters are not consistent because of this. Last night I fired up
the laptop and did find a "factor" difference when calculating various sizes. So, Don was right! Thank-you, Don. I hope this will end
the confusion I created and is not as helpful as first thought. Case closed.
Moving on. Also, Don gave me a printout of ten examples of conversions ranging from .320" to .25" restrictor diameters with corresponding
true diameters and some differed as much as .011". Not a biggie with the restrictor type but more of a biggie with the true type. .010"
makes a difference in flow with a true type. Checking the computer calc with the pi x r squared did match but Don's restrictor sizes did
not. I also accidently found Bill Lee's post showing the NCRLA's link to a beautiful conversion that is within .001-.002" of the computer
results, so I didn't ask what method Don used. Perhaps typos? The programming software I have used for this venturi stuff was used for the Del Monte
R+D pet food pilot plant at Terminal Island, CA to make experimental Chewlotta dog food bone molds. The design engineers wanted to know
the volume and parting line areas. The software calculates any closed shape geometry and volume accurately.
I also saw Randy Smith's recommended listing of venturi sizes showing his real world experience with stunt engines. Super stuff!
For me I think I will use the NCRLS's link for just standalone area to area conversions for starting point sizes after all. It's a lot easier
than using the computer.
Did you find my posts somewhat amusing? I thought so!
Tom