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; 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 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, 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 from the exhaust port, said axial distance being measured axially along an axis of said exhaust pipe front portion in an unbent position, wherein said axial distance is within a range of ten to twenty times of the diameter 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; 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 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, 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 from the exhaust port, said axial distance being measured axially along an axis of said exhaust pipe front portion in an unbent position, wherein said axial distance is within a range of ten to twenty times of the diameter of the exhaust port to aid in faster temperature rise within the catalytic adaptor.