Abstract: An exhaust gas recirculation (EGR) cooler for cooling exhaust gas includes at least one channel configured to allow the exhaust gas to flow through it, and a casing defining a cooling chamber around the at least one channel. The cooling chamber is configured to enable heat transfer between the exhaust gas and the coolant. The at least one channel has an interior surface and an exterior surface made of a first metal and a second metal, respectively, and configured to be in contact with the exhaust gas and the coolant, respectively. The second metal has a higher thermal conductivity than the first metal. The casing includes a coolant inlet and a coolant outlet configured to enable the coolant to enter and exit the cooling chamber, and an exhaust gas inlet and an exhaust gas outlet configured to enable the exhaust gas to enter and exit the at least one channel.

Abstract: An exhaust gas recirculation (EGR) cooler for cooling exhaust gas includes at least one channel configured to allow the exhaust gas to flow through it, and a casing defining a cooling chamber around the at least one channel. The cooling chamber is configured to enable heat transfer between the exhaust gas and the coolant. The at least one channel has an interior surface and an exterior surface made of a first metal and a second metal, respectively, and configured to be in contact with the exhaust gas and the coolant, respectively. The second metal has a higher thermal conductivity than the first metal. The casing includes a coolant inlet and a coolant outlet configured to enable the coolant to enter and exit the cooling chamber, and an exhaust gas inlet and an exhaust gas outlet configured to enable the exhaust gas to enter and exit the at least one channel.

Abstract: A method of making a piston with enhanced thermal conductivity. In one embodiment, the method includes providing a piston with an oil gallery, the piston made of a material; and depositing a layer of a material in the oil gallery, the material having a higher thermal conductivity than a thermal conductivity of the piston material. Another aspect of the invention is a piston having enhanced thermal conductivity.

Abstract: A method of making an aluminum piston is described. In one embodiment, the method includes placing a oil gallery core in a mold, the oil gallery core comprising a metal tube connected to a hollow inlet tube and a hollow outlet tube; introducing liquid aluminum into the mold around the oil gallery core; and allowing the liquid aluminum to solidify, the oil gallery core forming a channel in the piston. Aluminum pistons are also described.

Abstract: A piston with a cast bi-metallic dome feature and a method of making the piston. In one form, the piston is for use in a diesel engine, while in another, the piston is for use in a gasoline engine. The dome feature may include a laminate of a relatively high-temperature material (such as stainless steel) and a relatively low temperature material (such as aluminum or aluminum alloys) such that the portion of the dome made from the relatively high-temperature material is directly exposed to combustion within a cylinder into which the piston is placed. In another form, an aluminum coated stainless steel layer is used to form the dome. In one form, an ablation casting process may be used to manufacture the dome.

Abstract: A diesel piston with a cast bi-metallic dome and a method of making the piston. In one form, the dome may include a laminate of a relatively high-temperature material, for example, stainless steel, and a relatively low temperature material, for example, aluminum or aluminum alloys, such that the portion of the dome made from the relatively high-temperature material is directly exposed to combustion within a cylinder into which the piston is placed. In another form, an aluminum coated stainless steel ring is used to form the dome. In one form, an ablation casting process may be used to manufacture the dome.

Abstract: An aluminum-based diesel engine piston and a method of making the piston. The method involves casting the piston with complex geometries, including undercut or reentrant features. The casting uses an aggregate disposable mold that can be removed from the as-cast part. In one form, the complex geometry includes an undercut combustion bowl formed in the piston dome, while in another, it may include an internal cooling passage. The undercut bowl and internal passages may be produced using the aggregate disposable mold.

Abstract: A method of making a piston with enhanced thermal conductivity. In one embodiment, the method includes providing a piston with an oil gallery, the piston made of a material; and depositing a layer of a material in the oil gallery, the material having a higher thermal conductivity than a thermal conductivity of the piston material. Another aspect of the invention is a piston having enhanced thermal conductivity.

Abstract: A piston with a cast bi-metallic dome feature and a method of making the piston. In one form, the piston is for use in a diesel engine, while in another, the piston is for use in a gasoline engine. The dome feature may include a laminate of a relatively high-temperature material (such as stainless steel) and a relatively low temperature material (such as aluminum or aluminum alloys) such that the portion of the dome made from the relatively high-temperature material is directly exposed to combustion within a cylinder into which the piston is placed. In another form, an aluminum coated stainless steel layer is used to form the dome. In one form, an ablation casting process may be used to manufacture the dome.

Abstract: A method of making an aluminum piston is described. In one embodiment, the method includes placing a oil gallery core in a mold, the oil gallery core comprising a metal tube connected to a hollow inlet tube and a hollow outlet tube; introducing liquid aluminum into the mold around the oil gallery core; and allowing the liquid aluminum to solidify, the oil gallery core forming a channel in the piston. Aluminum pistons are also described.

Abstract: A diesel engine piston and a method of making the piston. The method involves casting the piston with complex geometries, including undercut features. The casting uses an aggregate disposable mold that can be removed from the as-cast part. In one form, the complex geometry includes an undercut combustion bowl formed in the piston dome, while in another, it may include an internal cooling passage. The undercut bowl and internal passages may be produced using the aggregate disposable mold.

Abstract: A diesel piston with a cast bi-metallic dome and a method of making the piston. In one form, the dome may include a laminate of a relatively high-temperature material, for example, stainless steel, and a relatively low temperature material, for example, aluminum or aluminum alloys, such that the portion of the dome made from the relatively high-temperature material is directly exposed to combustion within a cylinder into which the piston is placed. In another form, an aluminum coated stainless steel ring is used to form the dome. In one form, an ablation casting process may be used to manufacture the dome.