Abstract: An evaporable foam pattern for casting a metal water-cooled exhaust manifold for an internal combustion engine. The assembled pattern is formed of an evaporable foam polymeric material, such as polystyrene, and includes an inner exhaust conduit composed of a generally upright body portion and a generally curved elbow portion. The body portion is provided with a plurality of inlet ports connected to the exhaust passages of a bank of cylinders, while the elbow portion defines a downwardly facing outlet. The pattern also includes an outer water jacket which is spaced from the exhaust conduit to provide a water passage therebetween. Both the exhaust conduit and the outer jacket are composed of two longitudinally split halves or sections having abutting edges, and the abutting edges are joined together by an adhesive. Spacing ribs interconnect the inner surface of the jacket and the outer surface of the exhaust conduit to space the sections apart.

Abstract: An evaporable foam pattern for casting a metal air induction manifold for an internal combustion engine. The pattern is formed from an evaporable foam material, such as polystyrene, and in the assembled condition the pattern is in the form of an elongated body member having a generally rectangular cross section. One end of the body member is enclosed by an end wall while the opposite end of the body member is open. One of the side walls of the body member is provided with a plurality of generally parallel slots which are elongated in a lateral direction with respect to the longitudinal axis of the body member. The pattern is composed of a pair of longitudinal pattern sections each being generally U-shaped in cross section and having abutting edges disposed on a parting line. An adhesive joins the abutting edges. The parting line between the pattern section splits the opening in the end of the body member and all of the slots are formed in one pattern section.

Abstract: The assembled evaporable pattern, which is substantially identical in shape to the cast metal two-cycle engine block, includes a plurality of in-line cylinders each having an end open to the crankcase end of the pattern. Each cylinder includes an exhaust passage that communicates with an exhaust manifold that extends to the exterior of the pattern and each cylinder has at least one longitudinally extending transfer passage. The assembled pattern also includes cooling passages that surround each cylinder, as well as surrounding the exhaust manifold passage. The foam pattern is composed of a plurality of separate foam sections joined together by an adhesive along planar interfaces. A first of the sections extends from the crankcase end of the pattern to the lower end of the transfer passages, and a second section extends from the lower end of the transfer passages to a location intersecting the exhaust passages of the cylinders. A third section extends from the exhaust passages to the cylinder heads.

Abstract: An evaporable foam pattern for producing a cast metal head for a multiple cylinder engine. The assembled pattern includes an elongated block of evaporable foam material having opposed inner and outer faces. A plurality of generally circular head recesses are formed in the inner face and define the cylinder heads in the metal casting. The block is also formed with an internal passage including a group of annular chambers that surround the head recesses and channels interconnect adjacent chambers. The block also has an inlet which communicates with one end of the internal passage and an outlet that communicates with the opposite end of the passage. The pattern is composed of a pair of longitudinal pattern sections having abutted edges that are joined together by an adhesive. The heads, as well as the inlet and outlet, are located in one of the pattern sections, while the two sections in combination define the internal passage.

Abstract: A lost foam casting system (2) includes a sprue (8) have a receiving portion (56) for receiving molten metal (14) from a source (16), a distribution portion (58) with a plurality of radial fingers (59-62) for distributing the molten metal (14) radially outwardly, and a lower section (63) having a plurality of feed passages (35-38) receiving molten metal (14) from the respective radial fingers (59-62) and interconnected by thin flat support walls (39-42) providing a relatively rigid structure. Workpieces (18 and 20) and in-gates (23-25 and 26-28) are connected to the flat exterior surfaces (39 and 41) of the lower section (63) of the sprue (8) and fed with molten metal (14) from respective feed passages.