Abstract: A process for manufacturing a siamese-type clyinder block which is disclosed herein comprises a blank making step of providing a cylinder block blank in which a sleeve made of a cast iron is cast in each cylinder barrel of a siamese-type barrel made of an aluminum alloy and consisting of a plurality of cylinder barrels connected in series, and a mechanically working or machining step of forming the inner peripheral surface of each sleeve of the cylinder block blank into a true circle. The process is characterized in that the blank making step includes placing highly rigid sleeves each having a thickness set as large as 10% or more of the inner diameter thereof into a siamese-type cylinder barrel molding cavity in a mold and then pouring a molten metal of aluminum alloy under a pressure into the cavity to effect a casting. The sleeve is cast-in as it is at an ambient temperature or in a heated state.

Abstract: A siamese-type cylinder block blank which is composed so that upon the pouring a molten metal under a pressure, a sleeve of cast iron is cast in each cylinder barrel of a siamese-type cylinder barrel made of an aluminum alloy and consisting of a plurality of cylinder barrels connected in series. The cylinder block blank is characterized in that each sleeve cast presents a substantially oval configuration in section with the lengthwise axis parallel to the direction of cylinder barrels arranged, as a result of the reception of the solidification shrinkage force of each cylinder barrel.

Abstract: A method for manufacturing a siamese-type cylinder block, which comprises the steps of pouring under pressure a molten metal of aluminum alloy into a siamese-type cylinder barrel molding cavity with an expansion force applied to the sleeve placed in such cavity, and then removing the expansion force after the completion of solidification of the molten metal to cast a cylinder block blank, and subjecting the resulting blank to a working operation for forming the peripheral inner surface of the sleeve into a true circle.

Abstract: A process for casing a fiber-reinforced metal body by placing a shaped fibrous article made of a reinforcing fiber into a cavity in a casting mold and filling a molten metal into the shaped fibrous article to solidify it, the process further including the steps of pouring the molten metal into the cavity from the lower portion thereof, while venting gas present within the cavity through a gas vent passage having a very small opening communicating with the upper portion of the cavity, and closing the gas vent passage and completely solidifying the molten metal under a higher pressure.

Abstract: A process for casting a cylinder block blank made of light alloy provided with a cylinder barrel reinforced around its cylinder bore with a reinforcing tubular body and a crankcase provided continuous to the cylinder bore, which includes placing the reinforcing tubular body in a first cavity formed for shaping a cylinder barrel at the lower portion of a mold which is formed at its upper portion with a second cavity for shaping a crankcase communicating with the first cavity, and pouring a light alloy molten metal from the lower portion of the first cavity into the first and second cavities while simultaneously venting gas from the first and second cavities.

Abstract: A casting process which is disclosed herein comprises placing a breakable core into a cavity in a mold and pouring a molten metal under a pressure into the cavity by means of a plunger. The casting process is characterized in that the speed of plunger moved is controlled at three stages of first, second and third velocities, the second velocity being set higher than the first velocity and the third velocity being lower than the second velocity.

Abstract: A method for injecting molten metal in a vertical diecasting machine. In order to efficiently produce high quality castings, a molten metal is injected into a mold cavity with the upper part of the mold cavity communicating with the atmosphere, the mold cavity is occluded before the completion of the injection, and then the molten metal is pressurized to suppress the trapping of air or gases in the casting.

Abstract: A method of charging molten metal into a vertical die casting machine, wherein molten metal is introduced into a lower sleeve in which a lower plunger is slidably received, to store therein a mass of molten metal having a surface level not higher than the bottom of a molten metal inlet to a mold cavity. Next, an upper plunger is lowered to a predetermined position, raising the lower plunger to urge the molten metal upwardly and move it into the mold cavity. The upper plunger can then be moved to apply pressure to the molten metal. The method ensures smooth charging of molten metal and casting of a product free of casting defects.