Alterantive RX8 housing exhaust port

Following on from my previous post, the steel exhaust port insert is great apart from sealing it to the existing liner. Tig welding was possible but definitely not a preferred option.

Next option tried was to pocket out the area where an exhaust port would normally exist and press in a new piece from which a new port could be machined. This option is very involved but worked well. Aside from getting the correct fit for the insert, the most technical part was generating the 3D milling program that blends the exhaust port from typical Mazda port shape at liner to full round profile at manifold mount face: