An exhaust manifold for an internal combustion engine

摘要

An exhaust manifold for an internal combustion engine 10 is disclosed having two exhaust gas flow paths 12, 13 defined therein. A first flow path 12 directs exhaust gasses with no appreciable cooling effect to a three way catalyst 16 located downstream and the second flow path 13 includes water cooling for the exhaust gasses passing therethrough using coolant drawn from a main engine cooling circuit. One or more valves 15 are used to control the proportion of flow through the first and second flow passages 12 and 13 so as to regulate the temperature of the exhaust gasses entering the three way catalyst 16.