(Rev. 2, 1 May 2007)
Calculation Tools

Selecting A Mechanical Secondary Carburetor

Adapted by from data in the nomogram in “SELECTING A MECHANICAL SECONDARY CARBURETOR“ in the file “Selecting A Carburetor.pdf” on the Holley.com website: http://holley.com/data/TechService/Technical/Selecting%20A%20Carburetor.pdf Spreadsheet with curve fit: http://alteredz.com/tools/HolleyMechSecSizing.xls A spreadsheet that calculates the Mechanical Secondary carb flow needed, depending on the minumum rpm that Wide Open Throttle (WOT) will be applied, and the engine displacement (in cubic inches). This tool replicates the data in the nomogram to within +/- 6 cfm. Be aware that the advertised "size" of some carburetors are much lower than the actual flow that they are capable of producing at the standard 1.5 inHg. For instance, the Barry Grant Mighty Demon 650 mechanical secondary carb flows approximately 830 cfm. Right Click to "Save As"

Cam Timing vs. Compression Analysis

From the equations presented on: http://victorylibrary.com/mopar/cam-tech-c.htm A spreadsheet that calculates the cranking pressure (dynamic compression) and a "Volume Pressure Index" of an engine based on it's static compression ratio and camshaft seat timing specs. Right Click to "Save As"

Valve Spring Calculations

A spreadsheet that calculates different valve spring loads at various installed heights. Right Click to "Save As"

Tire and Engine RPM as a function of transmission, gearing and tire size

Right Click to "Save As"

Speedometer Driven Gear Calculations

A spreadsheet that calculates which speedometer driven gear to use. Right Click to "Save As"