Exhaust manifold made of heat-resistant cast steel

Abstract

An exhaust manifold made of heat-resistant cast steel comprising pluralities of flanges each having a hole connected to each exhaust port of a cylinder head of an engine with bolts, pluralities of ports connected to the flanges, and a convergence portion in which the ports are converging, the thickness of the flanges being 80-150% of that of the ports.

1 . An exhaust manifold made of heat-resistant cast steel comprising pluralities of flanges each having a hole connected to each exhaust port of a cylinder head of an engine with bolts, pluralities of ports connected to said flanges, and a convergence portion in which said ports are converging, the thickness of said flanges being 80-150% of that of said ports. 
   
   
       2 . The exhaust manifold made of heat-resistant cast steel according to  claim 1 , wherein hole-surrounding portions are 110-300% as thick as said flanges. 
   
   
       3 . The exhaust manifold made of heat-resistant cast steel according to  claim 1 , which has a ridge extending along each port from said convergence portion. 
   
   
       4 . The exhaust manifold made of heat-resistant cast steel according to  claim 3 , wherein the thickness of said ridges is 70-140% of that of said ports. 
   
   
       5 . The exhaust manifold made of heat-resistant cast steel according to  claim 2 , which has a ridge extending along each port from said convergence portion.