secondaries won't open on holley 3310

Ricks70Duster340 said

Disagree with saying vacuum carbs are a no-no on big cam engines. We are not talking about vacuum at idle, but when the engine is revving up and demanding more fuel. With him changing his secondary spring to white, the secondaries will start to open at a very low RPM. In fact, they open so fast he would notice a "bog" as they do so. No, no double pumper needed.

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Well it doesn't look he is having much success with springs. Vacuum secondary carburetors are great for a replacement of a factory carb on a Street engine built to factory specs.

Once you start building bigger they are a loss in performance . Nothing is better then mechanical. There is no wondering if your secondaries are working at wide open throttle. Vacuum secondary Carbs are for passenger cars , Trucks and RV's . Not for built high performance applications.

Most people drive on the 2bbl . When they use the 4bbl it is usually pushed in the wide open position.