Method of making a cast aluminum based engine block

A method of making a cast aluminum based engine block having one or more combustion chambers, the method comprising:

• (a) stationing a core assembly in a die casting assembly which is effective to provide a cavity when the assembly is closed to define a closed-deck block, said die casting assembly having means to reserve port openings and combustion chambers through the deck of the closed-deck block, said core assembly having a water soluble alkaline metal salt member selected from the group of KCl and NaCl, formed by die casting under pressure and heated to a shaped body effective to define in cooperation with said die casting assembly a submerged cast chamber, said salt member having at least one hollow cylindrical portion arranged to wrap about in spaced relation thereto one or more of said means to reserve combustion chambers, said core assembly also having a cylindrical iron liner spaced radially inwardly from said salt member and adapted to fit snugly about a portion of said means of said die casting assembly, and a resilient low melting metal mesh collar interposed between said core and liner to stabilize, support and center said liner on said core, said collar dissolved after the molten metal has been introduced into said cavity and is in place;
• (b) introducing molten aluminum based metal under pressure into said cavity to fill same and to form said block having said chamber;
• and
• (c) removing said salt member from said cast block by water dissolution, water being admitted to said chamber through said port openings and the dissolved salt member being withdrawn through said port openings.