Calculate Intake valve OD from RPM and CID
Calculate What Intake valve OD Would Be From RPM and CID.
To learn more about Mach Index or other theories try checking out these books on Amazon.com:
Scientific Design of Exhaust & Intake Systems (Engineering and Performance) : and
Internal Combustion Engine in Theory and Practice:
And A. Graham Bellís Performance Tuning in Theory and Practice..
VALVE / BORE Ratio The valve to bore ratio should be: 52-52.5% of the bore for Wedge heads. 53-53.5% for Canted valve, rotated canted valve (Mopar P/S hemi) and true Hemi. If you decrease intake exhaust ratio down to 70-71% you can move both intake and exhaust valves over to the exhaust side and increase intake valve size by .5-1%. Anytime you increase valve size over the above stated Valve/Bore ratio you will see a small gain in CFM but the discharge coefficient drops and takes your power with it. An over shrouded valve instills a host of nasty scenario's, the two worst being decreased discharge coefficient and increased reversion below and above intake tuned power band. (according to Darin Morgan)