Controlled pollution control valve by-pass device for carbureted internal combustion engine

摘要

A fuel saving device for a carbureted engine having a pollution control valve comprising a by-pass duct adapted to convey gases from the crankcase around the pollution control valve directly to the carburetor and a valve in the duct controlled by the manifold vacuum to open the valve at lower pressure in the manifold and close it at less depressed pressures.