PTS Flowbench Forum

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Postby maxracesoftware » Wed Jan 19, 2005 3:42 am

My first question is how do I reconcile my development experience, which leads me to believe that the optimum intake camshaft lift is 30% of the OD of the intake valve , with others (very informed others at that) suggesting lifts between 38% to 43% of intake OD. Is it simply the difference between a two valve head and a four valve head? Or are there are factors in play?



====== Intake Valve L/D Ratios ======
.37 % to .42 % Lift/Diameter Ratio for 2-Valve Heads

you would reduce the L/D Ratios by approx .916 PerCent to =>

.33892 to .38472 for all out max effort DragRacing type Cylinder Heads with 4 Valves

a good Street/Strip/Bracket Racing recommended L/D Ratio = .250 to .2844

also minimum recommended OEM L/D Ratios
for 4-Valve Heads would be approx .184 for pure street applications

for 2- Valve Heads = .201

and the Curtain and Valve Areas are equal at .25 L/D Ratio
regardless to whether 2 or 4 valves .

Meaux Racing Heads
MaxRace Software
PipeMax and ET_Analyst for DragRacers
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