sorry for the late respond... been trying to understand the formula and busy...
here is the formula to caculate the runner length.
L=[(ECD x 0.25 x V x 2) / (rpm x RV) - (D/2)
ECD = effective cam duration (720 - Adv duration - 30)
V= pressure wave speed (usually is 1300 ft/s)
RV = Reflective Value (this value i think is the which set of pressure wave you want to use. if you use 1 set of pressure wave mean the pressure wave will travel 1 time up and down of the runner. if you use 2 set of pressure wave mean it will travel 2 time up and down. this is to reduce the lenght of the runner as the time require to travel will be same.)
D = runner diameter in inches
the runner length must include the length from your intake manifold gasket to your inlet valve. so you will have to subtract the lenght of gasket to your valve to get your manifold runner lenght.
i am still trying to understand the rest of the stuff....
here is the formula to caculate the runner length.
L=[(ECD x 0.25 x V x 2) / (rpm x RV) - (D/2)
ECD = effective cam duration (720 - Adv duration - 30)
V= pressure wave speed (usually is 1300 ft/s)
RV = Reflective Value (this value i think is the which set of pressure wave you want to use. if you use 1 set of pressure wave mean the pressure wave will travel 1 time up and down of the runner. if you use 2 set of pressure wave mean it will travel 2 time up and down. this is to reduce the lenght of the runner as the time require to travel will be same.)
D = runner diameter in inches
the runner length must include the length from your intake manifold gasket to your inlet valve. so you will have to subtract the lenght of gasket to your valve to get your manifold runner lenght.
i am still trying to understand the rest of the stuff....
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