Abstract: The invention describes a process for producing light products, such as engine and diesel fuels, and fuel oils for conventional use by thermal conversion of heavy metal- and sulfur-rich-crude oil residues. Thermal cracking of the residues is done by mild cracking in several stages, where the residue remaining after separation of the conversion products of the preceding stage is fed to the respective subsequent stage.

Abstract: The invention relates to a process for producing accurately scaled, well-defined surfaces of workpieces made from carbonaceous cast iron and having tribologic properties, more particularly of cylinders or internal combustion engines, said surfaces being subjected to at least two operating cycles consisting of an electrochemical and a subsequent mechanical removal. To obtain a constant surface quality, at least the last operating cycle is carried out in a specified ratio between the electrochemical and the mechanical removal and this is a fixed removal ratio. Preferably, a metal bearing plateau percentage of 40 to 65% of the surface is produced with the last operating cycle.

Abstract: The invention relates to a method and an apparatus for the treatment of surfaces of a workpiece of carbon-containing cast iron, and in particular of blind holes in gray iron cast workpieces, by electrochemical stock removal and mechanical reaming-and-plating. Electrochemical stock removal and mechanical reaming and plating are carried out in separate steps whose operating parameters are independently adjustable, the mechanical stock removal being essentially confined to a reaming-and-plating of the surface which does not entail a closing of graphite flakes. A cylinder bore produced by the method of the invention with desired roughness will have a dark, lustrous surface.

Abstract: A valve element is formed with a groove or notch in the region of the valve seat. The valve element is then introduced into a crucible pot which has the outer shape of the valve, when coated, and a cover is placed thereover completing the shape of the valve, when coated. Granular coating material, for example "Colmonoy 6" (0.75% C, 4.25% Si, 13 to 20% Cr. remainder Ni, 4.75% Fe and 3% B), is placed on the valve element, the cover is then placed thereover, leaving a small gap of the thickness of the coating around the valve element. The assembly is then subjected to vacuum, about 10.sup.-6 -10.sup.-7 torr, and heated to liquefaction temperature of the armor-coating material, which will fill the space between the valve element and the crucible pot and cover, thus coating the valve element with a thin coating therearound, and a thick layer in the region of the groove of the valve element, which may be in the order of millimeters, whereas the remainder may be in the order of thousandths of a millimeter.

Abstract: A threaded cap screwed into the piston head with a sealed joint to a sleeve tube open and flanged at the other end are provided to encase the clamping screws that fasten the piston head and the upper piston body member and lower piston body member together. The casing thus formed shields the screws from possibly corrosive coolant that under operating conditions could work through the joints between the parts of a composite piston in spite of the clamping pressure of the screws. Each screw is screwed into the threaded cap at the piston head end and its head or a nut bears on the flange of the sleeve tube at the other end. The screws and their protective casings fit within bores in an annular strut forming a large part of the upper piston body member that butts against a low annular ridge on the underside of the piston head into which the end caps of the screw casings are screwed.