Patent ID: 9238993
Filing Date: 2016-01-19
CPC Classification: B21D,F01N,Y10T

Claim Text:
1. A method for making an exhaust manifold for internal combustion engines and the like, comprising: selecting a first metal sheet having a first wall thickness, and being constructed from a first metallic material; stamping from the first metal sheet an outer-most manifold half having a half clamshell shape with opposite side edges; selecting a second metal sheet having a second wall thickness which is different from the first wall thickness, and being constructed from a second metallic material which is different from the first metallic material; stamping from the second metal sheet an inner manifold half having a half clamshell shape which mates with the shape of the outer-most manifold half, and includes opposite side edges and at least one laterally extending aperture; rigidly joining the opposite side edges of the outer-most manifold half and the inner manifold half along a butt joint formed by the opposite side edges in a longitudinal direction to define a hollow exhaust manifold body having an inlet side and an outlet side; forming a port flange, and rigidly connecting the same to the inner manifold half along the inlet side of the exhaust manifold body; and forming an outlet flange, and rigidly connecting the same to the outer-most manifold half and the inner manifold half at the outlet side of the exhaust manifold body.