An internal combustion engine for a vehicle comprising: a cylinder head permitting entry of air fuel mixture for combustion, said cylinder head comprising an exhaust port through which hot exhaust gases are expelled, said exhaust port having a diameter (D); an exhaust device said exhaust device comprising: an exhaust pipe front portion connected to the exhaust port of the internal combustion engine , and a muffler unit , wherein said exhaust pipe front portion extends from the exhaust port for connecting with said muffler unit , wherein said exhaust pipe front portion includes a first exhaust pipe portion , said first exhaust pipe portion being configured to have a bent corner (C) and a second exhaust pipe portion having a rear end being configured to join said muffler unit ; a catalytic adaptor , wherein a portion of said first exhaust pipe portion extends horizontally rearward from said bent corner (C), for connecting said catalytic adaptor ; wherein said catalytic adaptor is a single structure secured between a rear end of first exhaust pipe portion and a front end of said second exhaust pipe portion ; a first catalytic converter which is enclosed within said catalytic adaptor ; characterized in that an upstream end of said catalytic adaptor is disposed at an axial distance (L) from the exhaust port , said axial distance (L) being measured axially along an axis of said exhaust pipe front portion in an unbent position, wherein said axial distance (L) is within a range of ten to twenty times of the diameter (D) of the exhaust port to aid in faster temperature rise within the catalytic adaptor . a cylinder head permitting entry of air fuel mixture for combustion, said cylinder head comprising an exhaust port through which hot exhaust gases are expelled, said exhaust port having a diameter (D); an exhaust device said exhaust device comprising: an exhaust pipe front portion connected to the exhaust port of the internal combustion engine , and a muffler unit , an exhaust pipe front portion connected to the exhaust port of the internal combustion engine , and a muffler unit , wherein said exhaust pipe front portion extends from the exhaust port for connecting with said muffler unit , wherein said exhaust pipe front portion includes a first exhaust pipe portion , said first exhaust pipe portion being configured to have a bent corner (C) and a second exhaust pipe portion having a rear end being configured to join said muffler unit ; a catalytic adaptor , wherein a portion of said first exhaust pipe portion extends horizontally rearward from said bent corner (C), for connecting said catalytic adaptor ; wherein said catalytic adaptor is a single structure secured between a rear end of first exhaust pipe portion and a front end of said second exhaust pipe portion ; a first catalytic converter which is enclosed within said catalytic adaptor ; characterized in that an upstream end of said catalytic adaptor is disposed at an axial distance (L) from the exhaust port , said axial distance (L) being measured axially along an axis of said exhaust pipe front portion in an unbent position, wherein said axial distance (L) is within a range of ten to twenty times of the diameter (D) of the exhaust port to aid in faster temperature rise within the catalytic adaptor . <EOS>