Abstract: A crankcase ventilation system withdraws vapors from the crankcase of an internal combustion engine by using intake manifold vacuum to transfer crankcase vapors from a position in the engine crankcase, away from any lubricant pool, into the air/fuel intake manifold system, thereby moving the crankcase vapors along with a controlled amount of bleed (ambient) air to the intake manifold of the engine. The engine crankcase is kept under negative pressure by careful sizing of the parts, and the intake tube for bleed air is the only air admission to the crankcase so as to maintain this negative pressure condition within the engine crankcase. The bleed air intake tube is located adjacent the outlet tube for combining crankcase vapors and bleed air, without particulate or contaminates from the crankcase, and directed to the engine fuel/air intake manifold through a thermal cooling chamber.

Abstract: A system for withdrawing vapors from the crankcase of an internal combustion engine and directing the vapors into the air intake manifold thereof for combustion within the engine is described which comprises a first vapor flow circuit interconnecting the crankcase in vapor flow communication with the air intake manifold at a region thereof where a vacuum is generated or maintained, the first circuit including in a described embodiment, an orifice and expansion chamber for expanding and cooling the vapors to an aerosol state; a second vapor flow circuit of generally lower flow impedance than that of the first circuit may be included on certain engine-fuel/air system types for interconnecting the crankcase in vapor flow communication with the air cleaner of the fuel/air system for conducting vapor to the carburetor at high throttle operating conditions.

Abstract: An improved system for ventilating and utilizing crankcase vapors in an internal combustion engine uses an air pump for feeding air to both the first and second air flow circuits of the system such that air and crankcase vapors will be withdrawn from the engine crankcase to the first circuit and directed to the engine intake system, while air will be added to the crankcase from the second circuit. The air pump is connected to and driven by the engine such that feeding of air to the first and second circuits is regulated in direct proportion to the rpm of the engine.

Abstract: In a first air flow circuit filtered ram air cooperating with an aspirator draws crankcase vapors from the crankcase of an internal combustion engine. Heavy particulate matter in the crankcase vapor is heated and further vaporized by a heat exchanger cooperating with an exhaust manifold of the engine. A second aspirator draws the vaporized particulate matter back into the original vapor steam of the first air flow circuit. The crankcase vapors mixed with the incoming ram air are then directed into the interior cavity of the carburetor air filter. In a second air flow circuit filtered ram air is directed into the crankcase and carburetor air filter cavity and in a third air flow circuit filtered air is drawn through a variable annular orifice and metered in accord with intake manifold pressure and directed into the engine air intake system below the carburetor throttle plate.