[ItBites]

You can tape some 1" tufts of yarn around / in the scoop opening and drive the car (have someone film from a car in the next lane) to determine if air goes in or out of the scoop while driving. This is cheap wind tunnel testing, but it works.

I suspect air is going in. The vacuum you refer to (Todd) would be created if the opening were parallel to the flow (Bernoulli principle), but the scoop opening is perpendicular to the flow. However, due to the low aspect ratio of the opening, I would think what is referred to as "edge effects" may reduce the "equivalent hydraulic diameter" to a point where the scoop is not particularly efficient at getting large volumes of air to your engine.

As far as your filter goes, you are correct that a 1"tall element, even with the flow thru the top is not enough for your engine (even if you have a 302). Go to the K&N website and they have a formula there for determining adequate filter area based on engine size and RPM. Carburetor size has nothing to do with it: Since inlet speeds in the venturis are not sonic, the flow in your carburetor is not choked and as an engine demands more flow, it will lower the manifold pressure and resultingly more air will flow into the same carburetor. This will not produce the best HP possible, however, since the manifold pressure is lower, the density of the mixture entering the cylinder is down and resultingly HP. This is why racer engines seem to use carburetors that are way larger than the typical formulas I've seen thrown around in these forums. The larger carburetor will support a higher manifold pressure for any given flow than a smaller carburetor, resulting in increased density of the mixture in the cylinder - and more HP, but only at the expense of signal and trottle response. But I digress... sorry to go on and on.


Dont count on the scoop force feeding your engine and don't count on making the best possible HP with a tiny filter.

Let me know if you do the yarn test...