Inlet and exhaust manifold flange thickness Feb 21, 2017 13:50:49 GMT Quote Select PostDeselect PostLink to PostMemberGive GiftBack to Top Post by sonus on Feb 21, 2017 13:50:49 GMT I am having some flanges cut to make an intake and exhaust manifolds for my Daimler V8. I am considering both stainless, mild steel and aluminium for the intake manifold. Which thickness should I have these cut in for each material? For the the exhaust it'll be either stainless or mild steel - what thickness should these be?And where can I get megaphones made that are Inner Ø28mm one side and inner Ø40mm the other side with a length of 175mm?Or is this easy to make out of a flat piece? If so how?