Hybrid Ceramic/Sand Core for Casting Metal Engine Parts with Passages or Holes Having a Cross Section Too Small for Sand Casting

An improved core pack for use in casting an engine cylinder block, the core pack having cores that define the internal cavities of the engine cylinder block, the improvement comprising:

• hybrid sand/ceramic cores for defining a coolant jacket having interbore sections that extend completely between the bridge regions of the cylinders;
• wherein the hybrid sand/ceramic cores have ceramic sections for defining the interbore sections.

An improved core pack for use in casting an engine cylinder block, the core pack having cores that define the internal cavities of the engine cylinder block, the improvement comprising:

• ceramic cores for defining a fluid flow network within the cylinder block;
• wherein the fluid flow network has at least one of the following features:
• a cross section of less than 10 millimeters or a bend radius of less than 5 millimeters.

An improved core pack for use in casting an engine cylinder head, the core pack having cores that define the internal cavities of the engine cylinder head, the improvement comprising:

• one or more hybrid sand/ceramic cores, each defining an air intake port having a swirl radius of less than 5 millimeters;
• wherein the hybrid sand/ceramic cores have ceramic sections for defining the swirl radius.

An improved core pack for use in casting an engine cylinder head, the core pack having cores that define the internal cavities of the engine cylinder head, the improvement comprising:

• one or more hybrid sand/ceramic cores, each defining a coolant jacket flow tube having a cross sectional dimension of less than 10 millimeters;
• wherein the hybrid sand/ceramic cores have ceramic sections for defining the cross sectional area of less than 10 millimeters.

An improved core pack for use in casting an engine cylinder head, the core pack having cores that define the internal cavities of the engine cylinder head, the improvement comprising:

• one or more hybrid sand/ceramic cores, each defining a surface of a coolant jacket having indentations or protrusions with a cross sectional dimension of less than 10 millimeters;
• wherein the hybrid sand/ceramic cores have ceramic sections for defining the cross sectional area of less than 10 millimeters.