Patent ID: 7454899

Claim:
A secondary air supply system for an internal combustion engine comprising: a cylinder head of the internal combustion engine including a row of cylinder head exhaust holes and a row of corresponding cylinder head air supply holes located between the cylinder head exhaust holes; an exhaust manifold attached to the cylinder head and including a manifold flange having a plurality of manifold exhaust holes communicating with corresponding ones of the plurality of cylinder head exhaust holes and with an exhaust collection pipe, and a plurality of manifold air supply holes communicating with corresponding ones of the plurality of cylinder head air supply holes; and a secondary air supply including: a separate lower shell having an inwardly facing surface and an opposed outwardly facing surface and a plurality of connection holes for alignment with a corresponding one of the plurality of manifold air supply holes, the outwardly facing surface of the lower shell abutting against the manifold flange, and following alignment of the plurality of connection holes with the corresponding one of the plurality of manifold air supply holes, the lower shell being secured to the manifold flange from the inwardly facing surface of the lower shell; a separate upper shell, having an inwardly facing surface and an outwardly facing surface and, only once the lower shell is secured to the manifold flange, a circumference of the upper shell being secured to a circumference of the lower shell, so that the upper and lower shells are joined with one another to define and form an air supply passage extending parallel to and laterally offset from the row of cylinder head air supply holes and the manifold, and a plurality of air supply branch passages, and each branch passage extending laterally from the air supply passage to one of the plurality of connection holes communicating with a corresponding one of the cylinder head air supply holes.