Catalytic converter exhaust section for an internal combustion engine

A catalytic converter exhaust section comprising:

• a first mounting plate with an inlet opening therethrough;
• a second mounting plate with an outlet opening therethrough;
• a plurality of substantially identical metallic catalytic converter substrates, each having a hexagonal cross section and an inlet end separated from an outlet end by six planar walls;
• said metallic substrates being attached to one another in parallel to form a compound cross section with an inlet side, an outlet side and an outer border defined by a portion of said planar walls, and said planar walls of adjacent metallic substrates being in contact with one another;
• a hollow cylindrically shaped tube with an inlet end separated from an outlet end by a wall impervious to exhaust, and being sized to surround said compound cross section;
• and
• means for affixing said compound cross section within said tube and between said first mounting plate and said second mounting plate such that said inlet opening of said first mounting plate opens to said inlet side of said compound cross section and said outlet opening of said second mounting plate opens to said outlet side of said compound cross section.