Abstract: An improved Roots type supercharger for use with high performance vehicle engines. The supercharger includes rotors within a casing having rotor lobes with raised apex lands that move in a sealing relationship to the casing inside wall and rotor ends that move in a sealing relationship to the inside wall of casing end plates. A plurality of grooves are formed in at least one of the land, rotor end and end plate inside wall to reduce leakage of gases through those seals. The grooves are preferably formed generally perpendicular to the path of gas leakage through the seal.

Abstract: An improved Roots type supercharger for use with high performance vehicle engines. In Roots type superchargers as the lobes of the two cooperating rotors mesh, air is compressed between the approaching lobe on one rotor and inter-lobe area on the other rotor. This rapidly and severely compressses the air caught at that nip, tending to bend the rotors, overload the bearings and the rotor end seals. Also, compression heating of that air overheats the supercharger and charge air. Both of these phenomena tend to shorten the useful life of the supercharger. To overcome this problem, a row of relief passages is provided through the face of each lobe communicating with a large interior volume within the lobe. As the perforated lobe approaches the inter-lobe area of the second rotor, the air in the nip passes through the relief passages, only slightly increasing the pressure of the relatively large volume within the lobe rather than highly increasing the pressure in the nip.

Abstract: The disclosure is directed to an improved aerodynamic helmet. The helmet has a continuous aerodynamic curvilinear front, side and top surfaces whereby the fluid flowing over and around the sides of the helmet flows in a substantially continuous flow direction from the forward curved area aft of a straight area at the greatest width or largest transverse dimensions of the helmet after leaving the surface influence thereof.

Abstract: In an internal combustion engine utilizing hydraulic valve lifters, a source of pressurized engine oil at a higher than normally expected pressure is supplied thereto. The oil delivered to the lifter galley is derived from either an engine oil pump which produces a higher pressure oil flow then conventionally desired for normal engine operation or a separate oil pump. The pressure setting of the oil output from either pump is determined by the engine RPM, i.e. higher pressure with higher engine RPM or from pump speed if an electrically operated separate pump is employed.

Abstract: A muffler for use with an internal combustion engine or the like having improved attenuation capabilities. The muffler of the disclosure comprises at least two separate passages interconnected in series with a single or multiple output exhaust manifold and a single or multiple tail pipe of an engine exhaust system. At least one of the passages has a length greater than the other or others. The total cross-sectional area of the passages is approximately equal to or greater than the cross-section of the single or multiple exhaust manifold and single or multiple tail pipe to eliminate back pressure and maintain column inertia. In an embodiment, a housing encloses the passages and the overall appearance is that of a conventional muffler. In still another embodiment, at least one of the passages within the housing are perforated with a plurality of apertures. These apertures can be all of the same dimension or can be of different cross-sectional areas.